Michael Fredericson, MD

All Publications

• Iliotibial Band Syndrome in Runners Biomechanical Implications and Exercise Interventions PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA Baker, R. L., Fredericson, M. 2016; 27 (1): 53-?

  Abstract

  Iliotibial band syndrome (ITBS) has known biomechanical factors with an unclear explanation based on only strength and flexibility deficits. Neuromuscular coordination has emerged as a likely reason for kinematic faults guiding research toward motor control. This article discusses ITBS in relation to muscle performance factors, fascial considerations, epidemiology, functional anatomy, strength deficits, kinematics, iliotibial strain and strain rate, and biomechanical considerations. Evidence-based exercise approaches are reviewed for ITBS, including related methods used to train the posterior hip muscles.

  View details for DOI 10.1016/j.pmr.2015.08.001

  View details for Web of Science ID 000367203700005

  View details for PubMedID 26616177

• Bone Stress Injuries in Runners PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA Tenforde, A. S., Kraus, E., Fredericson, M. 2016; 27 (1): 139-?

  Abstract

  Bone stress injuries (BSIs) are common running injuries and may occur at a rate of 20% annually. Both biological and biomechanical risk factors contribute to BSI. Evaluation of a runner with suspected BSI includes completing an appropriate history and physical examination. MRI grading classification for BSI has been proposed and may guide return to play. Management includes activity modification, optimizing nutrition, and addressing risk factors, including the female athlete triad. BSI prevention strategies include screening for risk factors during preparticipation evaluations, optimizing nutrition (including adequate caloric intake, calcium, and vitamin D), and promoting ball sports during childhood and adolescence.

  View details for DOI 10.1016/j.pmr.2015.08.008

  View details for Web of Science ID 000367203700009

  View details for PubMedID 26616181

• Participation in Ball Sports May Represent a Prehabilitation Strategy to Prevent Future Stress Fractures and Promote Bone Health in Young Athletes PM&R Tenforde, A. S., Sainani, K. L., Sayres, L. C., Milgrom, C., Fredericson, M. 2015; 7 (2): 222-225

  Abstract

  Sports participation has many benefits for the young athlete, including improved bone health. However, a subset of athletes may attain suboptimal bone health and be at increased risk for stress fractures. This risk is greater for female than for male athletes. In healthy children, high-impact physical activity has been shown to improve bone health during growth and development. We offer our perspective on the importance of promoting high-impact, multidirectional loading activities, including ball sports, as a method of enhancing bone quality and fracture prevention based on collective research. Ball sports have been associated with greater bone mineral density and enhanced bone geometric properties compared with participation in repetitive, low-impact sports such as distance running or nonimpact sports such as swimming. Runners and infantry who participated in ball sports during childhood were at decreased risk of future stress fractures. Gender-specific differences, including the coexistence of female athlete triad, may negate the benefits of previous ball sports on fracture prevention. Ball sports involve multidirectional loading with high ground reaction forces that may result in stiffer and more fracture-resistant bones. Encouraging young athletes to participate in ball sports may optimize bone health in the setting of adequate nutrition and in female athletes, eumenorrhea. Future research to determine timing, frequency, and type of loading activity could result in a primary prevention program for stress fracture injuries and improved life-long bone health.

  View details for DOI 10.1016/j.pmrj.2014.09.017

  View details for Web of Science ID 000349995500019

  View details for PubMedID 25499072

• Athlete Return-to-Play Decisions in Sports Medicine. AMA journal of ethics Tenforde, A. S., Fredericson, M. 2015; 17 (6): 511-514

  View details for DOI 10.1001/journalofethics.2015.17.6.ecas3-1506

  View details for PubMedID 26075977

• On the Horizon: Defining the Future of Sports Medicine and the Role of the Physiatrist PM&R Fredericson, M. 2012; 4 (10): 707-710

  View details for DOI 10.1016/j.pmrj.2012.08.016

  View details for Web of Science ID 000310718200001

  View details for PubMedID 23093214

• Influence of Sports Participation on Bone Health in the Young Athlete: A Review of the Literature PM&R Tenforde, A. S., Fredericson, M. 2011; 3 (9): 861-867

  Abstract

  Peak bone mass is attained during the second and third decades of life. Sports participation during the years that peak bone mass is being acquired may lead to adaptive changes that improve bone architecture through increased density and enhanced geometric properties. A review of the literature evaluating sports participation in young athletes, ages 10-30 years, revealed that sports that involve high-impact loading (eg, gymnastics, hurdling, judo, karate, volleyball, and other jumping sports) or odd-impact loading (eg, soccer, basketball, racquet games, step-aerobics, and speed skating) are associated with higher bone mineral composition, bone mineral density (BMD), and enhanced bone geometry in anatomic regions specific to the loading patterns of each sport. Repetitive low-impact sports (such as distance running) are associated with favorable changes in bone geometry. Nonimpact sports such as swimming, water polo, and cycling are not associated with improvements in bone mineral composition or BMD, and swimming may negatively influence hip geometry. Participating in sports during early puberty may enhance bone mass. Continued participation in sports appears to maintain the full benefits of increased peak bone mass, although former athletes who do not maintain participation in sports may retain some benefits of increased BMD. Long-term elite male cycling was reported to negatively influence bone health, and female adolescent distance running was associated with suppressed bone mineral accrual; confounding factors associated with participation in endurance sports may have contributed to those findings. In summary, young men and women who participate in sports that involve high-impact or odd-impact loading exhibit the greatest associated gains in bone health. Participation in nonimpact sports, such as swimming and cycling, is not associated with an improvement in bone health.

  View details for DOI 10.1016/j.pmrj.2011.05.019

  View details for Web of Science ID 000305438100010

  View details for PubMedID 21944303

• Patellofemoral Pain Syndrome CLINICS IN SPORTS MEDICINE Collado, H., Fredericson, M. 2010; 29 (3): 379-?

  Abstract

  Patellofemoral pain (PFP) syndrome is a frequently encountered overuse disorder that involves the patellofemoral region and often presents as anterior knee pain. PFP can be difficult to diagnose. Not only do the etiology, diagnosis, and treatment remain challenging, but the terminology used to describe PFP is used inconsistently and can be confusing. Patellofemoral pain syndrome (PFPS) seems to be multifactorial, resulting from a complex interaction among intrinsic anatomic and external training factors. Although clinicians frequently make the diagnosis of PFPS, no consensus exists about its etiology or the factors most responsible for causing pain. This article discusses the pathophysiology, diagnosis, and management of PFP.

  View details for DOI 10.1016/j.csm.2010.03.012

  View details for Web of Science ID 000280029700006

  View details for PubMedID 20610028

• Platelet-rich plasma compared with corticosteroid injection for chronic lateral elbow tendinosis. PM & R : the journal of injury, function, and rehabilitation Mishra, A., Collado, H., Fredericson, M. 2009; 1 (4): 366-370

  View details for DOI 10.1016/j.pmrj.2009.02.010

  View details for PubMedID 19627920

• Epidemiology and aetiology of marathon running injuries SPORTS MEDICINE Fredericson, M., Misra, A. K. 2007; 37 (4-5): 437-439

  Abstract

  Over the last 10-15 years, there has been a dramatic increase in popularity of running marathons. Numerous articles have reported on injuries to runners of all experience, with yearly incidence rates for injury reported to be as high as 90% in those training for marathons. To date, most of these studies have been cohort studies and retrospective surveys with remarkably few prospective studies. However, from the studies available, it is clear that more experienced runners are less prone to injury, with the number of years running being inversely related to incidence of injuries. For all runners, it is important to be fully recovered from any and all injury or illness prior to running a marathon. For those with less experience, a graduated training programme seems to clearly help prevent injuries with special attention to avoid any sudden increases in running load or intensity, with a particularly high risk for injury once a threshold of 40 miles/week is crossed. In both sexes, the most common injury by far was to the knee, typically on the anterior aspect (e.g. patellofemoral syndrome). Iliotibial band friction syndrome, tibial stress syndrome, plantar fasciitis, Achilles tendonitis and meniscal injuries of the knee were also commonly cited.

  View details for Web of Science ID 000246820600043

  View details for PubMedID 17465629

• Stress fractures in athletes. Topics in magnetic resonance imaging Fredericson, M., Jennings, F., Beaulieu, C., Matheson, G. O. 2006; 17 (5): 309-325

  Abstract

  A stress fracture is a partial or complete bone fracture that results from repeated application of stress lower than the stress required to fracture the bone in a single loading. Otherwise healthy athletes, especially runners, sustain stress injuries or fractures. Prevention or early intervention is the preferable treatment. However, it is difficult to predict injury because runners vary with regard to biomechanical predisposition, training methods, and other factors such as diet, muscle strength, and flexibility. Stress fractures account for 0.7% to 20% of all sports medicine clinic injuries. Track-and-field athletes have the highest incidence of stress fractures compared with other athletes. Stress fractures of the tibia, metatarsals, and fibula are the most frequently reported sites. The sites of stress fractures vary from sport to sport (eg, among track athletes, stress fractures of the navicular, tibia, and metatarsal are common; in distance runners, it is the tibia and fibula; in dancers, the metatarsals). In the military, the calcaneus and metatarsals were the most commonly cited injuries, especially in new recruits, owing to the sudden increase in running and marching without adequate preparation. However, newer studies from the military show the incidence and distribution of stress fractures to be similar to those found in sports clinics. Fractures of the upper extremities are relatively rare, although most studies have focused only on lower-extremity injuries. The ulna is the upper-extremity bone injured most frequently. Imaging plays a key role in the diagnosis and management of stress injuries. Plain radiography is useful when positive, but generally has low sensitivity. Radionuclide bone scanning is highly sensitive, but lacks specificity and the ability to directly visualize fracture lines. In this article, we focus on magnetic resonance imaging, which provides highly sensitive and specific evaluation for bone marrow edema, periosteal reaction as well as detection of subtle fracture lines.

  View details for PubMedID 17414993

• Effects of ball sports on future risk of stress fracture in runners CLINICAL JOURNAL OF SPORT MEDICINE Fredericson, M., Ngo, J., Cobb, K. 2005; 15 (3): 136-141

  Abstract

  To evaluate whether playing ball sports during childhood and adolescence is associated with the risk of stress fractures in runners later in life.Retrospective cohort study.National track and field championships, held at Stanford University.One hundred fifty-six elite female and 118 elite male distance runners, age 18 to 44 years.A 1-page questionnaire was used to collect data regarding ages during which athletes played basketball and soccer, as well as other important covariates and outcomes.Athletes reported the ages when stress fractures occurred. Time to event was defined as the number of years from beginning competitive running to the first stress fracture or to current age, if no fracture had occurred.In both men and women, playing ball sports in youth correlated with reduced stress fracture incidence later in life by almost half, controlling for possible confounders. In men, each additional year of playing ball sports conferred a 13% decreased incidence of stress fracture (adjusted hazard ratio [HR] and 95% confidence interval, 0.87 [0.79-0.95]. Among women with regular menses, the HR for each additional year of playing ball sports was similar: 0.87 (0.75-1.00); however, there was no effect of length of time played among women with irregular menses (HR, 1.03 [0.92-1.16]). In men, younger ages of playing ball sports conferred more protection against stress fractures (HR for each 1-year-older age at first exposure, 1.29 [1.14, 1.45]).Runners who participate during childhood and adolescence in ball sports may develop bone with greater and more symmetrically distributed bone mass, and with enhanced protection from future stress fractures.

  View details for Web of Science ID 000230329000004

  View details for PubMedID 15867555

• High hamstring tendinopathy in rummers - Meeting the challenges of diagnosis, treatment, and rehabiliatation PHYSICIAN AND SPORTSMEDICINE Fredericson, M., Moore, W., Guillet, M., Beaulieu, C. 2005; 33 (5): 32-43

  Abstract

  High hamstring tendinopathy is an uncommon overuse injury seen in running athletes. Patients typically report deep buttock or thigh pain. A detailed physical examination and, occasionally, imaging studies are necessary to confirm the diagnosis. Rehabilitation involves soft-tissue mobilization, frequent stretching, and progressive eccentric hamstring strengthening and core stabilization exercises. In recalcitrant cases, an ultrasound-guided corticosteroid injection into the tendon sheath can be helpful, and, occasionally, surgery may be necessary to release the scar tissue around the proximal hamstring muscles and the sciatic nerve.

  View details for Web of Science ID 000229192000006

  View details for PubMedID 20086362

• Core Stabilization Training for Middle- and Long-Distance Runners IAAF New Studies in Athletics Fredericson M, Moore T 2005; 20 (1): 25-37
• Iliotibial band syndrome in runners - Innovations in treatment SPORTS MEDICINE Fredericson, M., Wolf, C. 2005; 35 (5): 451-459

  Abstract

  Iliotibial band syndrome (ITBS) is the most common cause of lateral knee pain in runners. It is an overuse injury that results from repetitive friction of the iliotibial band (ITB) over the lateral femoral epicondyle, with biomechanical studies demonstrating a maximal zone of impingement at approximately 30 degrees of knee flexion. Training factors related to this injury include excessive running in the same direction on a track, greater-than-normal weekly mileage and downhill running. Studies have also demonstrated that weakness or inhibition of the lateral gluteal muscles is a causative factor in this injury. When these muscles do not fire properly throughout the support phase of the running cycle, there is a decreased ability to stabilise the pelvis and eccentrically control femoral abduction. As a result, other muscles must compensate, often leading to excessive soft tissue tightness and myofascial restrictions. Initial treatment should focus on activity modification, therapeutic modalities to decrease local inflammation, nonsteroidal anti-inflammatory medication, and in severe cases, a corticosteroid injection. Stretching exercises can be started once acute inflammation is under control. Identifying and eliminating myofascial restrictions complement the therapy programme and should precede strengthening and muscle re-education. Strengthening exercises should emphasise eccentric muscle contractions, triplanar motions and integrated movement patterns. With this comprehensive treatment approach, most patients will fully recover by 6 weeks. Interestingly, biomechanical studies have shown that faster-paced running is less likely to aggravate ITBS and faster strides are initially recommended over a slower jogging pace. Over time, gradual increases in distance and frequency are permitted. In the rare refractory case, surgery may be required. The most common procedure is releasing or lengthening the posterior aspect of the ITB at the location of peak tension over the lateral femoral condyle.

  View details for Web of Science ID 000229726900006

  View details for PubMedID 15896092

• Hip abductor weakness in distance runners with iliotibial band syndrome CLINICAL JOURNAL OF SPORT MEDICINE Fredericson, M., Cookingham, C. L., Chaudhari, A. M., Dowdell, B. C., Oestreicher, N., Sahrmann, S. A. 2000; 10 (3): 169-175

  Abstract

  To examine hip abductor strength in long-distance runners with iliotibial band syndrome (ITBS), comparing their injured-limb strength to their nonaffected limb and to the limbs of a control group of healthy long-distance runners; and to determine whether correction of strength deficits in the hip abductors of the affected runners through a rehabilitation program correlates with a successful return to running.Case series.Stanford University Sports Medicine Clinics.24 distance runners with ITBS (14 female, 10 male) were randomly selected from patients presenting to our Runners' Injury Clinic with history and physical examination findings typical for ITBS. The control group of 30 distance runners (14 females, 16 males) were randomly selected from the Stanford University Cross-Country and Track teams.Group differences in hip abductor strength, as measured by torque generated, were analyzed using separate two-tailed t-tests between the injured limb, non-injured limb, and the noninjured limbs of the control group. Prerehabilitation hip abductor torque for the injured runners was then compared with postrehabilitation torque after a 6-week rehabilitation program.Hip abductor torque was measured with the Nicholas Manual Muscle Tester (kg), and normalized for differences in height and weight among subjects to units of percent body weight times height (%BWh). Average prerehabilitation hip abductor torque of the injured females was 7.82%BWh versus 9.82%BWh for their noninjured limb and 10.19%BWh for the control group of female runners. Average prerehabilitation hip abductor torque of the injured males was 6.86%BWh versus 8.62%BWh for their noninjured limb and 9.73%BWh for the control group of male runners. All prerehabilitation group differences were statistically significant at the p < 0.05 level. The injured runners were then enrolled in a 6-week standardized rehabilitation protocol with special attention directed to strengthening the gluteus medius. After rehabilitation, the females demonstrated an average increase in hip abductor torque of 34.9% in the injured limb, and the males an average increase of 51.4%. After 6 weeks of rehabilitation, 22 of 24 athletes were pain free with all exercises and able to return to running, and at 6-months follow-up there were no reports of recurrence.Long distance runners with ITBS have weaker hip abduction strength in the affected leg compared with their unaffected leg and unaffected long-distance runners. Additionally, symptom improvement with a successful return to the preinjury training program parallels improvement in hip abductor strength.

  View details for Web of Science ID 000088773700004

  View details for PubMedID 10959926

• A comprehensive review of running injuries. Critical Reviews in Physical Medicine and Rehabilitation Fredericson M, Bergman AG 1999; 11: 1-34.
• Relaxin Receptor RXFP1 and RXFP2 Expression in Ligament, Tendon, and Shoulder Joint Capsule of Rats JOURNAL OF KOREAN MEDICAL SCIENCE Kim, J. H., Lee, S. K., Lee, S. K., Kim, J. H., Fredericson, M. 2016; 31 (6): 983-988

  Abstract

  Numerous musculoskeletal disorders are caused by thickened ligament, tendon stiffness, or fibrosis of joint capsule. Relaxin, a peptide hormone, can exert collagenolytic effect on ligamentous and fibrotic tissues. We hypothesized that local injection of relaxin could be used to treat entrapment neuropathy and adhesive capsulitis. Because hormonal effect depends on the receptor of the hormone on the target cell, it is important to confirm the presence of such hormonal receptor at the target tissue before the hormone therapy is initiated. The aim of this study was to determine whether there were relaxin receptors in the ligament, tendon, and joint capsular tissues of rats and to identify the distribution of relaxin receptors in these tissues. Transverse carpal ligaments (TCLs), inguinal ligaments, anterior cruciate ligaments (ACLs), Achilles tendons, and shoulder joint capsules were obtained from male Wistar rats. Western blot analysis was used to identify relaxin receptor isoforms RXFP1 and RXFP2. The distribution of relaxin receptors was determined by immunohistochemical staining. The RXFP1 isoform was found in all tissues examined. The RXFP2 isoform was present in all tissues but the TCLs. Its expression in ACLs tissues was relatively weak compared to that in other tissues. Our results revealed that RXFP1 and RXFP2 were distributed in distinctly different patterns according to the type of tissue (vascular endothelial cells, fibroblast-like cells) they were identified.

  View details for DOI 10.3346/jkms.2016.31.6.983

  View details for Web of Science ID 000377169000022

  View details for PubMedID 27247510

• Use Of Dietary Supplements, Energy and Protein Bars, Gels and Drinks Among Elite Collegiate Endurance Runners: 2692 Board #215 June 3, 9: 30 AM - 11: 00 AM. Medicine and science in sports and exercise Barrack, M. T., Fredericson, M., Tenforde, A. S., Kim, B., Kraus, E., Singh, S., Ratanapratum, J., Nattiv, A. 2016; 48 (5): 753-?

  View details for DOI 10.1249/01.mss.0000487261.91993.b7

  View details for PubMedID 27361328

• Piriformis Syndrome With Variant Sciatic Nerve Anatomy: A Case Report. PM & R : the journal of injury, function, and rehabilitation Kraus, E., Tenforde, A. S., Beaulieu, C. F., Ratliff, J., Fredericson, M. 2016; 8 (2): 176-179

  Abstract

  A 68-year-old male long distance runner presented with low back and left buttock pain, which eventually progressed to severe and debilitating pain, intermittently radiating to the posterior thigh and foot. A comprehensive workup ruled out possible spine or hip causes of his symptoms. A pelvic magnetic resonance imaging neurogram with complex oblique planes through the piriformis demonstrated variant anatomy of the left sciatic nerve consistent with the clinical diagnosis of piriformis syndrome. The patient ultimately underwent neurolysis with release of the sciatic nerve and partial resection of the piriformis muscle. After surgery the patient reported significant pain reduction and resumed running 3 months later. Piriformis syndrome is uncommon but should be considered in the differential diagnosis for buttock pain. Advanced imaging was essential to guide management.

  View details for DOI 10.1016/j.pmrj.2015.09.005

  View details for PubMedID 26377629

• Parallels with the Female Athlete Triad in Male Athletes SPORTS MEDICINE Tenforde, A. S., Barrack, M. T., Nattiv, A., Fredericson, M. 2016; 46 (2): 171-182

  Abstract

  Participation in sports offers many health benefits to athletes of both sexes. However, subsets of both female and male athletes are at increased risk of impaired bone health and bone stress injuries. The Female Athlete Triad (Triad) is defined as the interrelationship of low energy availability (with or without disordered eating), menstrual dysfunction, and low bone mineral density. The Triad may result in health consequences, including bone stress injuries. Our review presents evidence that an analogous process may occur in male athletes. Our review of the available literature indicates that a subset of male athletes may experience adverse health issues that parallel those associated with the Triad, including low energy availability (with or without disordered eating), hypogonadotropic hypogonadism, and low bone mineral density. Consequently, male athletes may be predisposed to developing bone stress injuries, and these injuries can be the first presenting feature of associated Triad conditions. We discuss the evidence for impaired nutrition, hormonal dysfunction, and low bone mineral density in a subset of male athletes, and how these health issues may parallel those of the Triad. With further research into the mechanisms and outcomes of these health concerns in active and athletic men, evidence-based guidelines can be developed that result in best practice.

  View details for DOI 10.1007/s40279-015-0411-y

  View details for Web of Science ID 000378134500003

  View details for PubMedID 26497148

• The Role of Cartilage Stress in Patellofemoral Pain MEDICINE AND SCIENCE IN SPORTS AND EXERCISE Besier, T. F., Pal, S., Draper, C. E., Fredericson, M., Gold, G. E., Delp, S. L., Beaupre, G. S. 2015; 47 (11): 2416-2422

  Abstract

  Elevated cartilage stress has been identified as a potential mechanism for retropatellar pain; however, there are limited data in the literature to support this mechanism. Females are more likely to develop patellofemoral pain than males, yet the causes of this dimorphism are unclear. We used experimental data and computational modeling to determine whether patients with patellofemoral pain had elevated cartilage stress compared with pain-free controls and test the hypothesis that females exhibit greater cartilage stress than males.We created finite element models of 24 patients with patellofemoral pain (11 males and 13 females) and 16 pain-free controls (8 males and 8 females) to estimate peak patellar cartilage stress (strain energy density) during a stair climb activity. Simulations took into account cartilage morphology from magnetic resonance imaging, joint posture from weight-bearing magnetic resonance imaging, and muscle forces from an EMG-driven model.We found no difference in peak patellar strain energy density between those with patellofemoral pain (1.9 ± 1.23 J·m(-3)) and control subjects (1.66 ± 0.75 J·m(-3), P = 0.52). Females exhibited greater cartilage stress compared with males (2.2 vs 1.3 J·m(-3), respectively; P = 0.0075), with large quadriceps muscle forces (3.7 body weight in females vs 3.3 body weight in males) and 23% smaller joint contact area (females, 467 ± 59 mm2, vs males, 608 ± 95 mm2).Patients with patellofemoral pain did not display significantly greater patellar cartilage stress compared with pain-free controls; however, there was a great deal of subject variation. Females exhibited greater peak cartilage stress compared with males, which might explain the greater prevalence of patellofemoral pain in females compared with that in males, but other mechanical and biological factors are clearly involved in this complex pathway to pain.

  View details for DOI 10.1249/MSS.0000000000000685

  View details for Web of Science ID 000362940900021

  View details for PubMedID 25899103

• Femoral Neck Stress Fractures and Imaging Features of Femoroacetabular Impingement PM&R Goldin, M., Anderson, C. N., Fredericson, M., Safran, M. R., Stevens, K. J. 2015; 7 (6): 584-592

  Abstract

  Prior literature has suggested an association between the radiographic signs of femoroacetabular impingement (FAI) and femoral neck stress fractures (FNSF) or femoral neck stress reactions (FNSR). At the time of the writing of this article, no study has described the association of FAI and FNSF/FNSR along with the need for surgical intervention and outcomes.To determine the prevalence of radiographic features of FAI in patients diagnosed with FNSF.Retrospective case series.Tertiary care, institutional setting.A medical records search program (Stanford Translational Research Integrated Database Environment, Stanford University, California) was used to retrospectively search for patients 18-40 years old with a history of FNSF or FNSR. The records were obtained from the period July 25, 2003, to September 23, 2011.For assessment of risk factors, plain radiographs and magnetic resonance imaging studies were reviewed for features of cam or pincer FAI. Medical records were reviewed to determine whether patients required operative intervention.Incidence of abnormal alpha (α) angle, abnormal anterior offset ratio, abnormal femoral head-neck junction, coxa profunda, positive crossover sign, and abnormal lateral center-to-edge angle.Twenty-one female and 3 male participants (mean age 27 years, range 19-39 years) were identified with magnetic resonance imaging evidence of femoral neck stress injury. Cam morphology was seen in 10 patients (42%). Pincer morphology could be assessed in 18 patients, with coxa profunda in 14 (78%) and acetabular retroversion in 6 (14%). Features of combined pincer and cam impingement were observed in 4 patients (17%). Seven patients (29%) had operative intervention, with 3 (12%) requiring internal fixation of their femoral neck fractures, and all had radiographic evidence of fracture union after surgery. Four patients (17%) had persistent symptoms after healing of their FNSF with conservative treatment and eventually required surgery for FAI, 3 had no pain at final follow-up 1 year post-surgery, and one patient was lost to follow-up.The results of the current study suggest that patients in the general population with femoral neck stress injuries have a higher incidence of bony abnormalities associated with pincer impingement, including coxa profunda and acetabular retroversion, although it is unclear whether pincer FAI is a true risk factor in the development of FNSF.

  View details for DOI 10.1016/j.pmrj.2014.12.008

  View details for Web of Science ID 000356053400005

• Identifying Sex-Specific Risk Factors for Low Bone Mineral Density in Adolescent Runners AMERICAN JOURNAL OF SPORTS MEDICINE Tenforde, A. S., Fredericson, M., Sayres, L. C., Cutti, P., Sainani, K. L. 2015; 43 (6): 1494-1504

  Abstract

  Adolescent runners may be at risk for low bone mineral density (BMD) associated with sports participation. Few prior investigations have evaluated bone health in young runners, particularly males.To characterize sex-specific risk factors for low BMD in adolescent runners.Cross-sectional study; Level of evidence, 3.Training characteristics, fracture history, eating behaviors and attitudes, and menstrual history were measured using online questionnaires. A food frequency questionnaire was used to identify dietary patterns and measure calcium intake. Runners (female: n = 94, male: n = 42) completed dual-energy x-ray absorptiometry (DXA) to measure lumbar spine (LS) and total body less head (TBLH) BMD and body composition values, including android-to-gynoid (A:G) fat mass ratio. The BMD was standardized to Z-scores using age, sex, and race/ethnicity reference values. Questionnaire values were combined with DXA values to determine risk factors associated with differences in BMD Z-scores in LS and TBLH and low bone mass (defined as BMD Z-score ≤-1).In multivariable analyses, risk factors for lower LS BMD Z-scores in girls included lower A:G ratio, being shorter, and the combination of (interaction between) current menstrual irregularity and a history of fracture (all P < .01). Later age of menarche, lower A:G ratio, lower lean mass, and drinking less milk were associated with lower TBLH BMD Z-scores (P < .01). In boys, lower body mass index (BMI) Z-scores and the belief that being thinner improves performance were associated with lower LS and TBLH BMD Z-scores (all P < .05); lower A:G ratio was additionally associated with lower TBLH Z-scores (P < .01). Thirteen girls (14%) and 9 boys (21%) had low bone mass. Girls with a BMI ≤17.5 kg/m(2) or both menstrual irregularity and a history of fracture were significantly more likely to have low bone mass. Boys with a BMI ≤17.5 kg/m(2) and belief that thinness improves performance were significantly more likely to have low bone mass.This study identified sex-specific risk factors for impaired bone mass in adolescent runners. These risk factors can be helpful to guide sports medicine professionals in evaluation and management of young runners at risk for impaired bone health.

  View details for DOI 10.1177/0363546515572142

  View details for Web of Science ID 000355379200027

• Running habits of competitive runners during pregnancy and breastfeeding. Sports health Tenforde, A. S., Toth, K. E., Langen, E., Fredericson, M., Sainani, K. L. 2015; 7 (2): 172-176

  Abstract

  Running is a popular sport that may be performed safely during pregnancy. Few studies have characterized running behavior of competitive female runners during pregnancy and breastfeeding.Women modify their running behavior during pregnancy and breastfeeding.Observational, cross-sectional study.Level 2.One hundred ten female long-distance runners who ran competitively prior to pregnancy completed an online survey characterizing training attitudes and behaviors during pregnancy and postpartum.Seventy percent of runners ran some time during their pregnancy (or pregnancies), but only 31% ran during their third trimester. On average, women reduced training during pregnancy, including cutting their intensity to about half of their nonpregnant running effort. Only 3.9% reported sustaining a running injury while pregnant. Fewer than one third (29.9%) selected fetal health as a reason to continue running during pregnancy. Of the women who breastfed, 84.1% reported running during breastfeeding. Most felt that running had no effect on their ability to breastfeed. Women who ran during breastfeeding were less likely to report postpartum depression than those who did not run (6.7% vs 23.5%, P = 0.051), but we did not detect the same association of running during pregnancy (6.5% vs 15.2%, P = 0.16).Women runners reported a reduction in total training while pregnant, and few sustained running injuries during pregnancy. The effect of running on postpartum depression was not clear from our findings.We characterized running behaviors during pregnancy and breastfeeding in competitive runners. Most continue to run during pregnancy but reduce total training effort. Top reasons for running during pregnancy were fitness, health, and maintaining routine; the most common reason for not running was not feeling well. Most competitive runners run during breastfeeding with little perceived impact.

  View details for DOI 10.1177/1941738114549542

  View details for PubMedID 25984264

• Variable Criteria for Patellofemoral Bracing Among Sports Medicine Professionals PM&R Solinsky, R., Beaupre, G. S., Fredericson, M. 2014; 6 (6): 498-505

  Abstract

  To examine whether the frequency of bracing, geographic region, clinical specialty, or percentage of practice devoted to knee pain influences the criteria used by sports medicine professionals to determine whether a brace should be prescribed for treating patients with nontraumatic patellofemoral pain syndrome.Cross-sectional study.Sports medicine practices in the United States.A total of 1307 athletic trainers, physical therapists, and sports medicine physicians recruited from the e-mail listings of the American Medical Society for Sports Medicine, the American Osteopathic Academy of Sports Medicine, the American Physical Therapy Association Sports Physical Therapy Section, the International Patellofemoral Study Group, the International Patellofemoral Retreat list, and National Collegiate Athletic Association Division 1 athletic team registries.Not applicable.Thirty-seven potential patellofemoral bracing criteria encompassing history and function, alignment, physical examination, previous treatments, and radiographic evidence.A total of 1307 of 7999 providers replied (response rate, 16.3%). Mean bracing frequencies were 19.8% for athletic trainers, 13.4% for physical therapists, and 25.1% for physicians. The mean number of total bracing criteria used was 10.5. The 10 most commonly cited criteria for prescribing a patellofemoral brace in descending order of frequency were: (1) hypermobile patella on physical examination; (2) positive J sign on physical examination; (3) failure of previous rehabilitation; (4) pain when performing squats or going up/down stairs on history; (5) success with previous taping; (6) pain with running activities on history; (7) pain with jumping activities on history; (8) increased dynamic Q angle; (9) vastus medialis oblique deficiency in timing or strength; and (10) positive apprehension sign on physical examination. No statistically significant trends were noted with regard to experience or percentage of practice devoted to knee pain. Increased bracing frequency was significantly associated with an increased number of bracing criteria (r = 0.89, P < .0001).This study identified little overall consensus and showed that significant differences exist in the criteria used to prescribe a brace for patellofemoral pain syndrome among specialties and in relation to bracing frequency.

  View details for DOI 10.1016/j.pmrj.2014.01.008

  View details for Web of Science ID 000337995200005

  View details for PubMedID 24440485

• Identifying Sex-Specific Risk Factors for Stress Fractures in Adolescent Runners MEDICINE AND SCIENCE IN SPORTS AND EXERCISE Tenforde, A. S., Sayres, L. C., McCurdy, M. L., Sainani, K. L., Fredericson, M. 2013; 45 (10): 1843-1851

  Abstract

  PURPOSE: Adolescent females and males participating in running represent a population at high risk of stress fracture. Few investigators have evaluated risk factors for prospective stress fracture in this population. METHODS: To better characterize risk factors for and incidence of stress fractures in this population, we collected baseline risk factor data on 748 competitive high school runners (442 girls and 306 boys) using an online survey. We then followed them prospectively for the development of stress fractures for an average of 2.3±1.2 total seasons of cross-country and track and field; follow-up data were available for 428 girls and 273 boys. RESULTS: We identified prospective stress fractures in 5.4% of girls (N=23) and 4.0% of boys (N=11). Tibial stress fractures were most common in girls, and the metatarsus was most frequently fractured in boys. Multivariate regression identified four independent risk factors for stress fractures in girls: prior fracture, BMI <19, late menarche (age menarche ≥15 years), and previous participation in gymnastics or dance. For boys, prior fracture and increased number of seasons were associated with an increased rate of stress fractures, whereas prior participation in basketball was associated with a decreased risk of stress fractures. CONCLUSION: Prior fracture represents the most robust predictor of stress fractures in both sexes. Low BMI, late menarche, and prior participation in gymnastics and dance are identifiable risk factors for stress fractures in girls. Participation in basketball appears protective in boys and may represent a modifiable risk factor for stress fractures. These findings may help guide future translational research and clinical care in the management and prevention of stress fractures in young runners.

  View details for DOI 10.1249/MSS.0b013e3182963d75

  View details for Web of Science ID 000330464700001

• Update on stress fractures in female athletes: epidemiology, treatment, and prevention. Current reviews in musculoskeletal medicine Chen, Y., Tenforde, A. S., Fredericson, M. 2013; 6 (2): 173-181

  Abstract

  Stress fractures are a common type of overuse injury in athletes. Females have unique risk factors such as the female athlete triad that contribute to stress fracture injuries. We review the current literature on risk factors for stress fractures, including the role of sports participation and nutrition factors. Discussion of the management of stress fractures is focused on radiographic criteria and anatomic location and how these contribute to return to play guidelines. We outline the current recommendations for evaluating and treatment of female athlete triad. Technologies that may aid in recovery from a stress fracture including use of anti-gravity treadmills are discussed. Prevention strategies may include early screening of female athlete triad, promoting early participation in activities that improve bone health, nutritional strategies, gait modification, and orthotics.

  View details for DOI 10.1007/s12178-013-9167-x

  View details for PubMedID 23536179

• Patellar maltracking is prevalent among patellofemoral pain subjects with patella alta: An upright, weightbearing MRI study JOURNAL OF ORTHOPAEDIC RESEARCH Pal, S., Besier, T. F., Beaupre, G. S., Fredericson, M., Delp, S. L., Gold, G. E. 2013; 31 (3): 448-457

  Abstract

  The purpose of this study is to determine if patellar maltracking is more prevalent among patellofemoral (PF) pain subjects with patella alta compared to subjects with normal patella height. We imaged 37 PF pain and 15 pain free subjects in an open-configuration magnetic resonance imaging scanner while they stood in a weightbearing posture. We measured patella height using the Caton-Deschamps, Blackburne-Peel, Insall-Salvati, Modified Insall-Salvati, and Patellotrochlear indices, and classified the subjects into patella alta and normal patella height groups. We measured patella tilt and bisect offset from oblique-axial plane images, and classified the subjects into maltracking and normal tracking groups. Patellar maltracking was more prevalent among PF pain subjects with patella alta compared to PF pain subjects with normal patella height (two-tailed Fisher's exact test, p<0.050). Using the Caton-Deschamps index, 67% (8/12) of PF pain subjects with patella alta were maltrackers, whereas only 16% (4/25) of PF pain subjects with normal patella height were maltrackers. Patellofemoral pain subjects classified as maltrackers displayed a greater patella height compared to the pain free and PF pain subjects classified as normal trackers (two-tailed unpaired t-tests with Bonferroni correction, p<0.017). This study adds to our understanding of PF pain in two ways-(1) we demonstrate that patellar maltracking is more prevalent in PF pain subjects with patella alta compared to subjects with normal patella height; and (2) we show greater patella height in PF pain subjects compared to pain free subjects using four indices commonly used in clinics.

  View details for DOI 10.1002/jor.22256

  View details for Web of Science ID 000313980600016

• Comparison of MRI and 18F-NaF PET/CT in patients with patellofemoral pain JOURNAL OF MAGNETIC RESONANCE IMAGING Draper, C. E., Quon, A., Fredericson, M., Besier, T. F., Delp, S. L., Beaupre, G. S., Gold, G. E. 2012; 36 (4): 928-932

  Abstract

  To determine whether bone metabolic activity corresponds to bone and cartilage damage in patients with patellofemoral pain.We acquired magnetic resonance imaging (MRI) and (18) F-NaF positron emission tomography (PET) / computed tomography (CT) scans of the knees of 22 subjects. We compared locations of increased tracer uptake on the (18) F-NaF PET images to bone marrow edema and cartilage damage visualized on MRI.We found that increased bone activity on (18) F-NaF PET does not always correspond to structural damage in the bone or cartilage as seen on MRI.Our results suggest that (18) F-NaF PET/CT may provide additional information in patellofemoral pain patients compared to MRI.

  View details for DOI 10.1002/jmri.23682

  View details for Web of Science ID 000308884300018

  View details for PubMedID 22549985

• Use of an Antigravity Treadmill for Rehabilitation of a Pelvic Stress Injury PM&R Tenforde, A. S., Watanabe, L. M., Moreno, T. J., Fredericson, M. 2012; 4 (8): 629-631

  Abstract

  Pelvic stress injuries are a relatively uncommon form of injury that require high index of clinician suspicion and usually MRI for definitive diagnosis. We present a case report of a 21-year-old female elite runner who was diagnosed with pelvic stress injury and used an antigravity treadmill during rehabilitation. She was able to return to pain-free ground running at 8 weeks after running at 95% body weight on the antigravity treadmill. Ten weeks from time of diagnosis, she competed at her conference championships and advanced to the NCAA Championships in the 10,000-meters. She competed in both races without residual pain. To our knowledge, this is the first published case report on use of an antigravity treadmill in rehabilitation of bone-related injuries. Our findings suggest that use of an antigravity treadmill for rehabilitation of a pelvic stress injury may result in appropriate bone loading and healing during progression to ground running and faster return to competition. Future research may identify appropriate protocols for recovery from overuse lower extremity injuries and other uses for this technology, including neuromuscular recovery and injury prevention.

  View details for DOI 10.1016/j.pmrj.2012.02.003

  View details for Web of Science ID 000308279400012

  View details for PubMedID 22920318

• Patellar tilt correlates with vastus lateralis: Vastus medialis activation ratio in maltracking patellofemoral pain patients JOURNAL OF ORTHOPAEDIC RESEARCH Pal, S., Besier, T. F., Draper, C. E., Fredericson, M., Gold, G. E., Beaupre, G. S., Delp, S. L. 2012; 30 (6): 927-933

  Abstract

  Patellofemoral (PF) pain is a common ailment of the lower extremity. A theorized cause for pain is patellar maltracking due to vasti muscle activation imbalance, represented as large vastus lateralis:vastus medialis (VL:VM) activation ratios. However, evidence relating vasti muscle activation imbalance to patellar maltracking is limited. The purpose of this study was to investigate the relationship between VL:VM activation ratio and patellar tracking measures, patellar tilt and bisect offset, in PF pain subjects and pain-free controls. We evaluated VL:VM activation ratio and VM activation delay relative to VL activation in 39 PF pain subjects and 15 pain-free controls during walking. We classified the PF pain subjects into normal tracking and maltracking groups based on patellar tilt and bisect offset measured from weight-bearing magnetic resonance imaging. Patellar tilt correlated with VL:VM activation ratio only in PF pain subjects classified as maltrackers. This suggests that a clinical intervention targeting vasti muscle activation imbalance may be effective only in PF pain subjects classified as maltrackers.

  View details for DOI 10.1002/jor.22008

  View details for Web of Science ID 000302466700012

  View details for PubMedID 22086708

• It is the most common form of arthritis and the leading cause of disability in older persons, affecting an estimated 27 million adults in the United States alone. Introduction. PM & R : the journal of injury, function, and rehabilitation Kennedy, D. J., Fredericson, M. 2012; 4 (5): S1-2

  View details for DOI 10.1016/j.pmrj.2012.03.003

  View details for PubMedID 22632686

• Neuromuscular Prehabilitation to Prevent Osteoarthritis After a Traumatic Joint Injury PM&R Tenforde, A. S., Shull, P. B., Fredericson, M. 2012; 4 (5): S141-S144

  Abstract

  Post-traumatic osteoarthritis (PTOA) is a process resulting from direct forces applied to a joint that cause injury and degenerative changes. An estimated 12% of all symptomatic osteoarthritis (OA) of the hip, knee, and ankle can be attributed to a post-traumatic cause. Neuromuscular prehabilitation is the process of improving neuromuscular function to prevent development of PTOA after an initial traumatic joint injury. Prehabilitation strategies include restoration of normative movement patterns that have been altered as the result of traumatic injury, along with neuromuscular exercises and gait retraining to prevent the development of OA after an injury occurs. A review of the current literature shows that no studies have been performed to evaluate methods of neuromuscular prehabilitation to prevent PTOA after a joint injury. Instead, current research has focused on management strategies after knee injuries, the value of exercise in the management of OA, and neuromuscular exercises after total knee arthroplasty. Recent work in gait retraining that alters knee joint loading holds promise for preventing the development of PTOA after joint trauma. Future research should evaluate methods of neuromuscular prehabilitation strategies in relationship to the outcome of PTOA after joint injury.

  View details for DOI 10.1016/j.pmrj.2012.01.004

  View details for Web of Science ID 000305873000020

  View details for PubMedID 22632693

• Patients with patellofemoral pain exhibit elevated bone metabolic activity at the patellofemoral joint JOURNAL OF ORTHOPAEDIC RESEARCH Draper, C. E., Fredericson, M., Gold, G. E., Besier, T. F., Delp, S. L., Beaupre, G. S., Quon, A. 2012; 30 (2): 209-213

  Abstract

  Patellofemoral pain is characterized by pain behind the kneecap and is often thought to be due to high stress at the patellofemoral joint. While we cannot measure bone stress in vivo, we can visualize bone metabolic activity using (18) F NaF PET/CT, which may be related to bone stress. Our goals were to use (18) F NaF PET/CT to evaluate whether subjects with patellofemoral pain exhibit elevated bone metabolic activity and to determine whether bone metabolic activity correlates with pain intensity. We examined 20 subjects diagnosed with patellofemoral pain. All subjects received an (18) F NaF PET/CT scan of their knees. Uptake of (18) F NaF in the patella and trochlea was quantified by computing the standardized uptake value and normalizing by the background tracer uptake in bone. We detected increased tracer uptake in 85% of the painful knees examined. We found that the painful knees exhibited increased tracer uptake compared to the pain-free knees of four subjects with unilateral pain (P?=?0.0006). We also found a correlation between increasing tracer uptake and increasing pain intensity (r(2) ?=?0.55; P?=?0.0005). The implication of these results is that patellofemoral pain may be related to bone metabolic activity at the patellofemoral joint.

  View details for DOI 10.1002/jor.21523

  View details for Web of Science ID 000298581200007

  View details for PubMedID 21812024

• Evaluation of the Athlete With Buttock Pain CURRENT SPORTS MEDICINE REPORTS Vasudevan, J. M., Smuck, M., Fredericson, M. 2012; 11 (1): 35-42

  Abstract

  Buttock (gluteal) pain is commonly experienced by athletes of all ages and activity levels. Evaluation of buttock pain can be challenging because the differential diagnoses are extensive. Symptoms may originate from the pelvis or hip or be referred from the lumbosacral spine or neurovascular structures. Few articles in the literature are dedicated to the primary complaint of buttock pain. The purpose of this article is to provide a clinical algorithm to assist the sports clinician in reaching an accurate diagnosis and initiating the appropriate treatment.

  View details for DOI 10.1249/JSR.0b013e3182423d71

  View details for Web of Science ID 000299162200008

  View details for PubMedID 22236824

• Iliotibial Band Syndrome: Soft Tissue and Biomechanical Factors in Evaluation and Treatment PM&R Baker, R. L., Souza, R. B., Fredericson, M. 2011; 3 (6): 550-561

  Abstract

  Muscle performance factors and altered loading mechanics have been linked to a variety of lower extremity musculoskeletal disorders. In this article, biomechanical risk factors associated with iliotibial band syndrome (ITBS) are described, and a strategy for incorporating these factors into the clinical evaluation of and treatment for that disorder is presented. Abnormal movement patterns in runners and cyclists with ITBS are discussed, and the pathophysiological characteristics of this syndrome are considered in light of prior and current studies in anatomy. Differential diagnoses and the use of imaging, medications, and injections in the treatment of ITBS are reviewed. The roles of hip muscle strength, kinematics, and kinetics are detailed, and the assessment and treatment of muscle performance factors are discussed, with emphasis on identifying and treating movement dysfunction. Various stages of rehabilitation, including strengthening progressions to reduce soft-tissue injury, are described in detail. ITBS is an extremely common orthopedic condition that presents with consistent dysfunctional patterns in muscle performance and movement deviation. Through careful assessment of lower quarter function, the clinician can properly identify individuals and initiate treatment.

  View details for DOI 10.1016/j.pmrj.2011.01.002

  View details for Web of Science ID 000305437700008

  View details for PubMedID 21665168

• Reliability and Accuracy of a Video Analysis Protocol to Assess Core Ability PM&R McDonald, D. A., Delgadillo, J. Q., Fredericson, M., McConnell, J., Ther, G. D., Hodgins, M., Besier, T. F. 2011; 3 (3): 204-211

  Abstract

  To develop and test a method to measure core ability in healthy athletes with 2-dimensional video analysis software (SiliconCOACH). Specific objectives were to: (1) develop a standardized exercise battery with progressions of increasing difficulty to evaluate areas of core ability in elite athletes; (2) develop an objective and quantitative grading rubric with the use of video analysis software; (3) assess the test-retest reliability of the exercise battery; (4) assess the interrater and intrarater reliability of the video analysis system; and (5) assess the accuracy of the assessment.Test-retest repeatability and accuracy.Testing was conducted in the Stanford Human Performance Laboratory, Stanford University, Stanford, CA.Nine female gymnasts currently training with the Stanford Varsity Women's Gymnastics Team participated in testing.Participants completed a test battery composed of planks, side planks, and leg bridges of increasing difficulty. Subjects completed two 20-minute testing sessions within a 4- to 10-day period. Two-dimensional sagittal-plane video was captured simultaneously with 3-dimensional motion capture.The main outcome measures were pelvic displacement and time that elapsed until failure occurred, as measured with SiliconCOACH video analysis software. Test-retest and interrater and intrarater reliability of the video analysis measures was assessed. Accuracy as compared with 3-dimensional motion capture also was assessed.Levels reached during the side planks and leg bridges had an excellent test-retest correlation (r(2) = 0.84, r(2) = 0.95). Pelvis displacements measured by examiner 1 and examiner 2 had an excellent correlation (r(2) = 0.86, intraclass correlation coefficient = 0.92). Pelvis displacements measured by examiner 1 during independent grading sessions had an excellent correlation (r(2) = 0.92). Pelvis displacements from the plank and from a set of combined plank and side plank exercises both had an excellent correlation with 3-dimensional motion capture measures (r(2) = 0.92, r(2) = 0.90).Core ability test battery with SiliconCOACH grading method is an accurate and reliable way to assess core ability exercise performance.

  View details for DOI 10.1016/j.pmrj.2010.12.007

  View details for Web of Science ID 000305437400004

  View details for PubMedID 21402366

• Differences in Patellofemoral Kinematics between Weight-Bearing and Non-Weight-Bearing Conditions in Patients with Patellofemoral Pain JOURNAL OF ORTHOPAEDIC RESEARCH Draper, C. E., Besier, T. F., Fredericson, M., Santos, J. M., Beaupre, G. S., Delp, S. L., Gold, G. E. 2011; 29 (3): 312-317

  Abstract

  Patellar maltracking is thought to be one source of patellofemoral pain. Measurements of patellar tracking are frequently obtained during non-weight-bearing knee extension; however, pain typically arises during highly loaded activities, such as squatting, stair climbing, and running. It is unclear whether patellofemoral joint kinematics during lightly loaded tasks replicate patellofemoral joint motion during weight-bearing activities. The purpose of this study was to: evaluate differences between upright, weight-bearing and supine, non-weight-bearing joint kinematics in patients with patellofemoral pain; and evaluate whether the kinematics in subjects with maltracking respond differently to weight-bearing than those in nonmaltrackers. We used real-time magnetic resonance imaging to visualize the patellofemoral joint during dynamic knee extension from 30° to 0° of knee flexion during two conditions: upright, weight-bearing and supine, non-weight-bearing. We compared patellofemoral kinematics measured from the images. The patella translated more laterally during the supine task compared to the weight-bearing task for knee flexion angles between 0° and 5° (p = 0.001). The kinematics of the maltrackers responded differently to joint loading than those of the non-maltrackers. In subjects with excessive lateral patellar translation, the patella translated more laterally during upright, weight-bearing knee extension for knee flexion angles between 25° and 30° (p = 0.001). However, in subjects with normal patellar translation, the patella translated more laterally during supine, non-weight-bearing knee extension near full extension (p = 0.001). These results suggest that patellofemoral kinematics measured during supine, unloaded tasks do not accurately represent the joint motion during weight-bearing activities.

  View details for DOI 10.1002/jor.21253

  View details for Web of Science ID 000287173500002

  View details for PubMedID 20949442

• Patellar Maltracking Correlates With Vastus Medialis Activation Delay in Patellofemoral Pain Patients AMERICAN JOURNAL OF SPORTS MEDICINE Pal, S., Draper, C. E., Fredericson, M., Gold, G. E., Delp, S. L., Beaupre, G. S., Besier, T. F. 2011; 39 (3): 590-598

  Abstract

  Delayed onset of vastus medialis (VM) activity compared with vastus lateralis activity is a reported cause for patellofemoral pain. The delayed onset of VM activity in patellofemoral pain patients likely causes an imbalance in muscle forces and lateral maltracking of the patella; however, evidence relating VM activation delay to patellar maltracking is sparse. The aim of this study was to investigate the relationship between VM activation delay and patellar maltracking measures in pain-free controls and patellofemoral pain patients.Patellar tilt and bisect offset, measures of patellar tracking, correlate with VM activation delay in patellofemoral pain patients classified as maltrackers.Case control study; Level of evidence, 3.Vasti muscle activations were recorded in pain-free (n = 15) and patellofemoral pain (n = 40) participants during walking and jogging. All participants were scanned in an open-configuration magnetic resonance scanner in an upright weightbearing position to acquire the position of the patella with respect to the femur. Patellar tilt and bisect offset were measured, and patellofemoral pain participants were classified into normal tracking and maltracking groups.Correlations between VM activation delay and patellar maltracking measures were statistically significant in only the patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset (R(2) = .89, P < .001, with patellar tilt during walking; R(2) = .75, P = .012, with bisect offset during jogging). There were no differences between the means of activation delays in pain-free and all patellofemoral pain participants during walking (P = .516) or jogging (P = .731).There was a relationship between VM activation delay and patellar maltracking in the subgroup of patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset.A clinical intervention such as VM retraining may be effective in only a subset of patellofemoral pain participants-namely, those with excessive tilt and excessive bisect offset measures. The results highlight the importance of appropriate classification of patellofemoral pain patients before selection of a clinical intervention.

  View details for DOI 10.1177/0363546510384233

  View details for Web of Science ID 000288063900019

  View details for PubMedID 21076015

• Comparison of Quadriceps Angle Measurements Using Short-Arm and Long-Arm Goniometers: Correlation With MRI PM&R Draper, C. E., Chew, K. T., Wang, R., Jennings, F., Gold, G. E., Fredericson, M. 2011; 3 (2): 111-116

  Abstract

  To compare the reliability of quadriceps-angle (Q-angle) measurements performed using a short-arm goniometer and a long-arm goniometer and to assess the accuracy of goniometer-based Q-angle measurements compared with anatomic Q angles derived from magnetic resonance imaging (MRI).An intra- and interobserver reliability study.University hospital.Eighteen healthy subjects with no history of knee pain, trauma, or prior surgery were examined.Two physicians, blinded to subject identity, measured Q angles on both knees of all subjects using 2 goniometers: (1) a short-arm goniometer and (2) a long-arm goniometer. Q angles were derived from axial MRIs of the subjects' hip and knees.The intra- and interobserver reliabilities of each goniometer were assessed using the intraclass correlation coefficient (ICC). The comparison between clinical and MRI-based Q angles was assessed by using the ICC and a paired t-test.Intra- and interobserver reliabilities of the long-arm goniometer (intraobserver ICC, 0.92; interobserver ICC, 0.88) were better than those of the short-arm goniometer (intraobserver ICC, 0.78; interobserver ICC, 0.56). Although both goniometers measured Q angles that were moderately correlated to the MRI-based measurements (ICC, 0.40), the clinical Q angles were underestimated compared with the MRI-based anatomic Q angles (P < .05).The results of this study suggest that, although reproducible Q-angle measurements can be performed using standardized patient positioning and a long-arm goniometer, methods to improve the accuracy of clinical Q-angle measurements are needed.

  View details for DOI 10.1016/j.pmrj.2010.10.020

  View details for Web of Science ID 000305437300004

  View details for PubMedID 21333949

• Overuse Injuries in High School Runners: Lifetime Prevalence and Prevention Strategies PM&R Tenforde, A. S., Sayres, L. C., McCurdy, M. L., Collado, H., Sainani, K. L., Fredericson, M. 2011; 3 (2): 125-131

  Abstract

  To evaluate lifetime prevalence and risk factors for overuse injuries in high school athletes currently participating in long-distance running and provide recommendations for injury prevention strategies.Retrospective study design.Twenty-eight high schools in the San Francisco Bay Area.A total of 442 female and 306 male athletes, ages 13-18 years, who are on cross-country and track and field teams.Online survey with questions that detailed previous injuries sustained and risk factors for injury.Previous overuse injuries and association of risk factors to injury (including training variables, dietary patterns, and, in girls, menstrual irregularities).Previous injuries were reported by 68% of female subjects and 59% of male subjects. More injury types were seen in girls (1.2 ± 1.1 versus 1.0 ± 1.0, P < .01). Both genders had similar participation in running (2.5 ± 2.2 versus 2.3 ± 2.1 years), and previous injury prevalence followed a similar pattern: tibial stress injury (girls, 41%; boys, 34%), ankle sprain (girls, 32%; boys, 28%), patellofemoral pain (girls, 21%; boys, 16%), Achilles tendonitis (girls, 9%; boys, 6%), iliotibial band syndrome (girls, 7%; boys, 5%), and plantar fasciitis (girls, 5%; boys, 3%). Higher weekly mileage was associated with previous injuries in boys, (17.1 ± 11.9 versus 14.1 ± 11.5, P < .05) but not in girls (14.4 ± 10.2 versus 12.6 ± 11.8, not significant). A strong association between higher mileage and faster performances was seen in both groups. No association between previous injury and current dietary patterns (including disordered eating and calcium intake) or menstrual irregularities was seen.The majority of athletes currently participating in high school cross-country and track and field have a history of sustaining an overuse injury, with girls having a higher prevalence of injury. A modest mileage reduction may represent a modifiable risk factor for injury reduction. Future research is needed to evaluate the effects of incorporating a comprehensive strength training program on the prospective development of overuse injury and performance in this population.

  View details for DOI 10.1016/j.pmrj.2010.09.009

  View details for Web of Science ID 000305437300006

  View details for PubMedID 21333951

• Femoral Stress Fractures Micheo W. ed. Common Problems in Rehabilitation Medicine: Musculoskeletal, Sports, and Occupational Medicine Fredericson M, Collado H 2011
• New Developments in Magnetic Resonance Imaging Techniques For Shoulder Instability in Athletes Open Access Journal of Sports Medicine McAdams T, Fredericson M, Vogelsong M, Gold G 2011; 1 (1)
• Imaging and Musculoskeletal Modeling to Investigate the Mechanical Aetiology of Patellofemoral Pain Anterior Knee Pain and Patellar Instability, 2nd Edition Besier T, Draper C, Saikat P, Fredericson M, Gold G, Delp S, Beaupre G 2011
• Lower Quarter Injury Prevention in Running Sports Functional Training Handbook Fredericson M, Akuthota V 2011
• Illiotibial Band Syndrome Micheo W. ed. Common problems in Rehabilitation Medicine: Musculoskeletal, Sports, and Ocuupational Medicine Fredericson M, Collado H 2011
• The Knee O'Connor F, Wilder R, eds. Textbook of Running Medicine 2nd Edition Fredericson M, Arroyo J, McConnell J. 2011
• Evaluating the relationship of calcium and vitamin D in the prevention of stress fracture injuries in the young athlete: a review of the literature. PM & R : the journal of injury, function, and rehabilitation Tenforde, A. S., Sayres, L. C., Sainani, K. L., Fredericson, M. 2010; 2 (10): 945-949

  Abstract

  Calcium and vitamin D are recognized as 2 components of nutrition needed to achieve and maintain bone health. Calcium and vitamin D have been clearly shown to improve bone density and prevent fractures at all ages. However, the literature is conflicting as to the role of these nutrients in young athletes ages 18 to 35 years, both for bone development and for the prevention of bone overuse injuries. Differences in findings may relate to study design. Although retrospective and cross-sectional studies have had mixed results, the authors of prospective studies have consistently demonstrated a relationship of increased calcium intake with an improvement in bone density and a decrease in fracture risk. A randomized trial in female military recruits demonstrated that calcium/vitamin D supplementation reduced the incidence of stress fractures. A prospective study in young female runners demonstrated reduced incidence of stress fractures and increased bone mineral density with increased dietary calcium intake. Findings from both studies suggest female athletes and military recruits who consumed greater than 1500 mg of calcium daily exhibited the largest reduction in stress fracture injuries. To date, no prospective studies have been conducted in male athletes or in adolescent athletes. In most studies, males and nonwhite participants were poorly represented. Evidence regarding the relationship of vitamin D intake with the prevention of fractures in athletes is also limited. More prospective studies are needed to evaluate the role of calcium and vitamin D intake in prevention of stress fracture injuries in both male and female adolescent athletes, particularly those participating in sports with greater incidences of stress fracture injury.

  View details for DOI 10.1016/j.pmrj.2010.05.006

  View details for PubMedID 20970764

• High Hamstring Tendinopathy: MRI and Ultrasound Imaging and Therapeutic Efficacy of Percutaneous Corticosteroid Injection AMERICAN JOURNAL OF ROENTGENOLOGY Zissen, M. H., Wallace, G., Stevens, K. J., Fredericson, M., Beaulieu, C. F. 2010; 195 (4): 993-998

  Abstract

  The goals of this study were to review the MRI and sonographic findings in patients diagnosed clinically with high hamstring tendinopathy and to evaluate the efficacy of ultrasound-guided corticosteroid injections in providing symptomatic relief.MRI is more sensitive than ultrasound in detecting peritendinous edema and tendinopathy at the proximal hamstring origin. Fifty percent of patients had symptomatic improvement lasting longer than 1 month after percutaneous corticosteroid injection, and 24% of patients had symptom relief for more than 6 months.

  View details for DOI 10.2214/AJR.09.3674

  View details for Web of Science ID 000282033600030

  View details for PubMedID 20858830

• Patellofemoral pain: is there a role for orthoses? PM & R : the journal of injury, function, and rehabilitation Powers, C. M., Berke, G. M., Clary, M. D., Fredericson, M. 2010; 2 (8): 771-776

  View details for DOI 10.1016/j.pmrj.2010.07.001

  View details for PubMedID 20709305

• Basic Appearance of Ultrasound Structures and Pitfalls PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA McDonald, S., Fredericson, M., Roh, E. Y., Smuck, M. 2010; 21 (3): 461-?

  Abstract

  The role of ultrasound in musculoskeletal imaging is expanding as technology advances and clinicians become better educated about its clinical applications. The main use of musculoskeletal ultrasound to physiatrists is to examine the soft tissues of the body and to diagnose pathologic changes. Ultrasound can be used to assist clinicians in performing interventional procedures. However, to successfully integrate this technology into their clinical practices, physicians must be familiar with the normal and abnormal appearance of tissues. They also must recognize the clinically relevant limitations and pitfalls associated with the use of ultrasound.

  View details for DOI 10.1016/j.pmr.2010.04.002

  View details for Web of Science ID 000282151400003

  View details for PubMedID 20797545

• Femur Rotation and Patellofemoral Joint Kinematics: A Weight-Bearing Magnetic Resonance Imaging Analysis JOURNAL OF ORTHOPAEDIC & SPORTS PHYSICAL THERAPY Souza, R. B., Draper, C. E., Fredericson, M., Powers, C. M. 2010; 40 (5): 277-285

  Abstract

  Controlled laboratory study using a cross-sectional design.To compare patellofemoral joint kinematics, femoral rotation, and patella rotation between females with patellofemoral pain (PFP) and pain-free controls using weight-bearing kinematic magnetic resonance imaging.Recently, it has been recognized that patellofemoral malalignment may be the result of femoral motion as opposed to patella motion.Fifteen females with PFP and 15 pain-free females between the ages of 18 and 45 years participated in this study. Kinematic imaging of the patellofemoral joint was performed using a vertically open magnetic resonance imaging system. Axial-oblique images were obtained using a fast gradient-echo pulse sequence. Images were acquired at a rate of 1 image per second while subjects performed a single-limb squat. Measures of femur and patella rotation (relative to the image field of view), lateral patella tilt, and lateral patella displacement were made from images obtained at 45 degrees , 30 degrees , 15 degrees , and 0 degrees of knee flexion. Group differences were assessed using a mixed-model analysis of variance with repeated measures.When compared to the control group, females with PFP demonstrated significantly greater lateral patella displacement at all angles evaluated and significantly greater lateral patella tilt at 30 degrees , 15 degrees , and 0 degrees of knee flexion. Similarly, greater medial femoral rotation was observed in the PFP group at 45 degrees , 15 degrees , and 0 degrees of knee flexion when compared to the control group. No group differences in patella rotation were found.Altered patellofemoral joint kinematics in females with PFP appears to be related to excessive medial femoral rotation, as opposed to lateral patella rotation. Our results suggest that the control of femur rotation may be important in restoring normal patellofemoral joint kinematics. J Orthop Sports Phys Ther 2010;40(5):277-285, Epub 12 March 2010. doi:10.2519/jospt.2010.3215.

  View details for DOI 10.2519/jospt.2010.3215

  View details for Web of Science ID 000277583600004

  View details for PubMedID 20436239

• Electronic web-based surveys: an effective and emerging tool in research. PM & R : the journal of injury, function, and rehabilitation Tenforde, A. S., Sainani, K. L., Fredericson, M. 2010; 2 (4): 307-309

  View details for DOI 10.1016/j.pmrj.2010.02.004

  View details for PubMedID 20430335

• Thoracic outlet syndrome. PM & R : the journal of injury, function, and rehabilitation Lee, J., Laker, S., Fredericson, M. 2010; 2 (1): 64-70

  View details for DOI 10.1016/j.pmrj.2009.12.001

  View details for PubMedID 20129515

• New developments in magnetic resonance imaging techniques for shoulder instability in athletes. Open access journal of sports medicine McAdams, T. R., Fredericson, M., Vogelsong, M., Gold, G. 2010; 1: 137-142

  Abstract

  Magnetic resonance (MR) imaging can be a very useful tool in the evaluation of instability in the athlete's shoulder. Technical options of MR imaging, such as arthrography, higher power magnets, and shoulder positioning, have enhanced MR evaluation of the shoulder. This update discusses the application of new MR techniques to a variety of shoulder instability patterns, including anterior instability, posterior instability, and atraumatic multidirectional instability. Specific applications of MR imaging in the postoperative patient is discussed. Finally, we describe the future directions of MR imaging in the setting of shoulder instability.

  View details for PubMedID 24198551

• Adhesive capsulitis: a new management protocol to improve passive range of motion. PM & R : the journal of injury, function, and rehabilitation Mitra, R., Harris, A., Umphrey, C., Smuck, M., Fredericson, M. 2009; 1 (12): 1064-1068

  Abstract

  To examine the short-term efficacy of a nonoperative shoulder protocol for the treatment of adhesive capsulitis.A retrospective chart review was used to collect data for a 3-year period.Academic tertiary medical center.28 consecutive patients diagnosed as having adhesive capsulitis were identified and managed with a new protocol.The protocol consisted of the administration of a suprascapular nerve block, the subsequent injection of an intra-articular steroid, and then the injection of an anesthetic agent with brisement normal saline volume dilation. The final step was manipulation of the shoulder.A paired t test was used to examine the difference in the preprocedure and postprocedure passive range of motion (flexion and abduction). The average shoulder abduction before the procedure was 89.5 degrees ; this improved by an average of 51.7 degrees (P<.0001). The average shoulder flexion improved from 117.3 degrees by an average of 37.7 degrees (P<.0001). There was no significant difference in either abduction or flexion based on age, gender, or chronicity of symptoms. White patients experienced significantly more improvement in abduction than did nonwhite patients.This study suggests that this adhesive capsulitis management protocol is effective and produces a significant improvement in the passive range of motion immediately after the procedure.

  View details for DOI 10.1016/j.pmrj.2009.10.005

  View details for PubMedID 20006315

• Dynamic Ultrasound to Diagnose Subluxating Biceps Femoris Tendon over the Fibular Head: A Case Report PM&R Huang, L., Stevens, K. J., Fredericson, M. 2009; 1 (7): 681-683

  View details for DOI 10.1016/j.pmrj.2009.02.009

  View details for Web of Science ID 000208411700011

  View details for PubMedID 19627962

• Changes in Posterior Lumbar Disk Contour Abnormality with Flexion-Extension Movement in Subjects with Low Back Pain and Degenerative Disk Disease PM&R Lee, S., Lee, J., Butts, K., Carragee, E., Fredericson, M. 2009; 1 (6): 541-546

  Abstract

  To determine whether posterior lumbar disk contour dimensions differ in the flexed seated, upright seated, and extended seated positions.Two subgroups of subjects with degenerative disk disease were compared: those with central posterior disk bulge (at L4-5 or L5-S1 levels) and those with a dark nucleus pulposus without posterior disk bulge (L3-4, L4-5, and/or L5-S1 levels).Academic medical center.Eight subjects with a central disk bulge and 9 subjects with a dark nucleus pulposus on magnetic resonance imaging.Not applicable.Quantitative comparisons of posterior disk contour between neutral, flexed, and extended sitting positions.Of 8 subjects with central disk bulge, spinal flexion (from the neutral position) produced a decreased disk contour in all subjects, whereas spinal extension (from the neutral position) produced an increased disk contour in 6 subjects, a decreased disk contour in 1 subject, and no measurable change in 1 subject. Changes in posterior disk contour in subjects with a dark nucleus pulposus were variable. Approximately half increased and half decreased, but no relation to position was determined.The results of this pilot study suggest a consistent pattern of decreased posterior disk contour with spinal flexion and increased posterior disk contour with spinal extension in subjects with central disk bulge, but not in those with a dark nucleus pulposus.

  View details for DOI 10.1016/j.pmrj.2009.03.014

  View details for Web of Science ID 000208411600006

• Knee muscle forces during walking and running in patellofemoral pain patients and pain-free controls JOURNAL OF BIOMECHANICS Besier, T. F., Fredericson, M., Gold, G. E., Beaupre, G. S., Delp, S. L. 2009; 42 (7): 898-905

  Abstract

  One proposed mechanism of patellofemoral pain, increased stress in the joint, is dependent on forces generated by the quadriceps muscles. Describing causal relationships between muscle forces, tissue stresses, and pain is difficult due to the inability to directly measure these variables in vivo. The purpose of this study was to estimate quadriceps forces during walking and running in a group of male and female patients with patellofemoral pain (n = 27, 16 female; 11 male) and compare these to pain-free controls (n = 16, 8 female; 8 male). Subjects walked and ran at self-selected speeds in a gait laboratory. Lower limb kinematics and electromyography (EMG) data were input to an EMG-driven musculoskeletal model of the knee, which was scaled and calibrated to each individual to estimate forces in 10 muscles surrounding the joint. Compared to controls, the patellofemoral pain group had greater co-contraction of quadriceps and hamstrings (p = 0.025) and greater normalized muscle forces during walking, even though the net knee moment was similar between groups. Muscle forces during running were similar between groups, but the net knee extension moment was less in the patellofemoral pain group compared to controls. Females displayed 30-50% greater normalized hamstring and gastrocnemius muscle forces during both walking and running compared to males (p<0.05). These results suggest that some patellofemoral pain patients might experience greater joint contact forces and joint stresses than pain-free subjects. The muscle force data are available as supplementary material.

  View details for DOI 10.1016/j.jbiomech.2009.01.032

  View details for Web of Science ID 000266299300016

  View details for PubMedID 19268945

• Using Real-Time MRI to Quantify Altered Joint Kinematics in Subjects with Patellofemoral Pain and to Evaluate the Effects of a Patellar Brace or Sleeve on Joint Motion JOURNAL OF ORTHOPAEDIC RESEARCH Draper, C. E., Besier, T. F., Santos, J. M., Jennings, F., Fredericson, M., Gold, G. E., Beaupre, G. S., Delp, S. L. 2009; 27 (5): 571-577

  Abstract

  Abnormal patellofemoral joint motion is a possible cause of patellofemoral pain, and patellar braces are thought to alleviate pain by restoring normal joint kinematics. We evaluated whether females with patellofemoral pain exhibit abnormal patellofemoral joint kinematics during dynamic, weight-bearing knee extension and assessed the effects of knee braces on patellofemoral motion. Real-time magnetic resonance (MR) images of the patellofemoral joints of 36 female volunteers (13 pain-free controls, 23 patellofemoral pain) were acquired during weight-bearing knee extension. Pain subjects were also imaged while wearing a patellar-stabilizing brace and a patellar sleeve. We measured axial-plane kinematics from the images. Females with patellofemoral pain exhibited increased lateral translation of the patella for knee flexion angles between 0 degrees and 50 degrees (p = 0.03), and increased lateral tilt for knee flexion angles between 0 degrees and 20 degrees (p = 0.04). The brace and sleeve reduced the lateral translation of the patella; however, the brace reduced lateral displacement more than the sleeve (p = 0.006). The brace reduced patellar tilt near full extension (p = 0.001), while the sleeve had no effect on patellar tilt. Our results indicate that some subjects with patellofemoral pain exhibit abnormal weight-bearing joint kinematics and that braces may be effective in reducing patellar maltracking in these subjects.

  View details for DOI 10.1002/jor.20790

  View details for Web of Science ID 000265009900002

  View details for PubMedID 18985690

• Magnetic Resonance Imaging Abnormalities in the Shoulder and Wrist Joints of Asymptomatic Elite Athletes PM&R Fredericson, M., Ho, C., Waite, B., Jennings, F., Peterson, J., Williams, C., Mathesonn, G. O. 2009; 1 (2): 107-116

  Abstract

  To characterize abnormalities on magnetic resonance images (MRI) in the shoulder and wrist joints of asymptomatic elite athletes to better define the range of "normal" findings in this population.Cohort study.Academic medical center.Division IA collegiate volleyball players (n=12), swimmers (n=6), and gymnasts (n=15) with no history of injury or pain and normal physical examination results.None.Grade of severity of MRI changes of the shoulder and wrist joints. A 3- to 4-year follow-up questionnaire was administered to determine the clinical significance of the asymptomatic findings.All athletes demonstrated at least mild imaging abnormalities in the joints evaluated. Shoulder: Volleyball players had moderate and severe changes primarily in the labrum (50% moderate, 8% severe), rotator cuff (25% moderate, 17% severe), bony structures (33% moderate), and tendon/muscle (25% moderate, 8% severe). Swimmers had moderate changes primarily in the labrum (83% moderate) and ligament (67% moderate). Wrist: All gymnasts had changes in the wrist ligaments (40% mild, 60% moderate), tendons (53% mild, 47% moderate), and cartilage (60% mild, 33% moderate, 7% severe). Most gymnasts exhibited bony changes (20% normal, 47% mild, 26% moderate, 7% severe), the presence of cysts/fluid collections (80%), and carpal tunnel changes (53%). Swimmers had no wrist abnormalities. At follow-up interview, only 1 swimmer and 1 volleyball player reported shoulder problems during the study. Additionally, only 1 gymnast reported a wrist injury during their career.Asymptomatic elite athletes demonstrate MRI changes of the shoulder (swimmers and volleyball players) and wrist (gymnasts) similar to those associated with abnormalities for which medical treatment and sometimes surgery are advised. Given the somewhat high frequency of these asymptomatic findings, care must be taken to correlate clinical history and physical examination with MRI findings in these patients with symptoms.

  View details for DOI 10.1016/j.pmrj.2008.09.004

  View details for Web of Science ID 000208411100004

• Cochrane Review: Theraputic ultrasound for treating patellofemoral pain syndrome The Cochrane Collaboration, JohnWiley & Sons Ltd Mak J, Collado H, Fredericson M 2009
• The Influence of Femoral Internal and External Rotation on Cartilage Stresses within the Patellofemoral Joint JOURNAL OF ORTHOPAEDIC RESEARCH Besier, T. F., Gold, G. E., Delp, S. L., Fredericson, M., Beaupre, G. S. 2008; 26 (12): 1627-1635

  Abstract

  Internal and external rotation of the femur plays an important role in defining the orientation of the patellofemoral joint, influencing contact areas, pressures, and cartilage stress distributions. The purpose of this study was to determine the influence of femoral internal and external rotation on stresses in the patellofemoral cartilage. We constructed finite element models of the patellofemoral joint using magnetic resonance (MR) images from 16 volunteers (8 male and 8 female). Subjects performed an upright weight-bearing squat with the knee at 60 degrees of flexion inside an open-MR scanner and in a gait laboratory. Quadriceps muscle forces were estimated for each subject using an electromyographic-driven model and input to a finite element analysis. Hydrostatic and octahedral shear stresses within the cartilage were modeled with the tibiofemoral joint in a "neutral" position and also with the femur rotated internally or externally by 5 degrees increments to +/-15 degrees . Cartilage stresses were more sensitive to external rotation of the femur, compared with internal rotation, with large variation across subjects. Peak patellar shear stresses increased more than 10% with 15 degrees of external rotation in 75% of the subjects. Shear stresses were higher in the patellar cartilage compared to the femoral cartilage and patellar cartilage stresses were more sensitive to femoral rotation compared with femoral cartilage stress. Large variation in the cartilage stress response between individuals reflects the complex nature of the extensor mechanism and has clinical relevance when considering treatment strategies designed to reduce cartilage stresses by altering femoral internal and external rotation.

  View details for DOI 10.1002/jor.20663

  View details for Web of Science ID 000260934700012

  View details for PubMedID 18524000

• Feasibility of using real-time MRI to measure joint kinematics in 1.5T and open-bore 0.5T systems JOURNAL OF MAGNETIC RESONANCE IMAGING Draper, C. E., Santos, J. M., Kourtis, L. C., Besier, T. F., Fredericson, M., Beaupre, G. S., Gold, G. E., Delp, S. L. 2008; 28 (1): 158-166

  Abstract

  To test the feasibility and accuracy of measuring joint motion with real-time MRI in a 1.5T scanner and in a 0.5T open-bore scanner and to assess the dependence of measurement accuracy on movement speed.We developed an MRI-compatible motion phantom to evaluate the accuracy of tracking bone positions with real-time MRI for varying movement speeds. The measurement error was determined by comparing phantom positions estimated from real-time MRI to those measured using optical motion capture techniques. To assess the feasibility of measuring in vivo joint motion, we calculated 2D knee joint kinematics during knee extension in six subjects and compared them to previously reported measurements.Measurement accuracy decreased as the phantom's movement speed increased. The measurement accuracy was within 2 mm for velocities up to 217 mm/s in the 1.5T scanner and 38 mm/s in the 0.5T scanner. We measured knee joint kinematics with small intraobserver variation (variance of 0.8 degrees for rotation and 3.6% of patellar width for translation).Our results suggest that real-time MRI can be used to measure joint kinematics when 2 mm accuracy is sufficient. They can also be used to prescribe the speed of joint motion necessary to achieve certain measurement accuracy.

  View details for DOI 10.1002/jmri.21413

  View details for Web of Science ID 000257865800021

  View details for PubMedID 18581329

• Introduction to diagnostic musculoskeletal ultrasound - Part 2: Examination of the lower limb AMERICAN JOURNAL OF PHYSICAL MEDICINE & REHABILITATION Chew, K., Stevens, K. J., Wang, T., Fredericson, M., Lew, H. L. 2008; 87 (3): 238-248

  Abstract

  This is the second of two articles focusing on ultrasound examination of musculoskeletal components of the upper and lower limbs. Treatment of musculoskeletal injuries is based on establishing an accurate diagnosis. No one would dispute that a good history and physical examination by a competent clinician can help achieve that in the majority of cases. However, musculoskeletal imaging is also an essential adjunct in the work-up of many musculoskeletal disorders. This article describes the ultrasound examination of the lower limb in terms of anatomic structure. Normal and pathologic ultrasound features of these structures, including muscles, tendons, ligaments, bursae, and other soft tissues of the lower limb, will be described by reviewing several representative pathologies commonly seen in musculoskeletal medicine.

  View details for DOI 10.1097/PHM.0b013e31816198c2

  View details for Web of Science ID 000253342200012

  View details for PubMedID 18174843

• Stress Injury at the Femoral Lesser Trochanter in Distance Runners. American Journal of Roentgenology. Nguyen J, Peterson J, Biswal S, Beaulieu C, Fredericson M 2008; 190 (6): 1616-1620
• The Effect of a Single Session of Posterior to Anterior Spinal Mobilization on Pain Response and Lumbar Extension in Persons with Non-Specific Low Back Pain. Physical Therapy. Powers CM, Beneck G, Kulig K, Landel R, Fredericson M 2008; 88 (4): 1-9
• Do Capacitively Coupled Electric Fields Accelerate Tibial Stress Fracture Healing? A Randomized Controlled Trial. American Journal of Sports Medicine. Beck B, Bergman A, Matheson G, Fredericson M, Marcus R 2008; 36 (3): 545-553
• Rheumatic Diseases Presenting as Sports-Related Injuries SPORTS MEDICINE Jennings, F., Lambert, E., Fredericson, M. 2008; 38 (11): 917-930

  Abstract

  Most individuals seeking consultation at sports medicine clinics are young, healthy athletes with injuries related to a specific activity. However, these athletes may have other systemic pathologies, such as rheumatic diseases, that may initially mimic sports-related injuries. As rheumatic diseases often affect the musculoskeletal system, they may masquerade as traumatic or mechanical conditions. A systematic review of the literature found numerous case reports of athletes who presented with apparent mechanical low back pain, sciatica pain, hip pain, meniscal tear, ankle sprain, rotator cuff syndrome and stress fractures and who, on further investigation, were found to have manifestations of rheumatic diseases. Common systemic, inflammatory causes of these musculoskeletal complaints include ankylosing spondylitis (AS), gout, chondrocalcinosis, psoriatic enthesopathy and early rheumatoid arthritis (RA). Low back pain is often mechanical among athletes, but cases have been described where spondyloarthritis, especially AS, has been diagnosed. Neck pain, another common mechanical symptom in athletes, can be an atypical presentation of AS or early RA. Hip or groin pain is frequently related to injuries in the hip joint and its surrounding structures. However, differential diagnosis should be made with AS, RA, gout, psudeogout, and less often with haemochromatosis and synovial chondochromatosis. In athletes presenting with peripheral arthropathy, it is mandatory to investigate autoimmune arthritis (AS, RA, juvenile idiopathic arthritis and systemic lupus erythematosus), crystal-induced arthritis, Lyme disease and pigmented villonodular synovitis. Musculoskeletal soft tissue disorders (bursitis, tendinopathies, enthesitis and carpal tunnel syndrome) are a frequent cause of pain and disability in both competitive and recreational athletes, and are related to acute injuries or overuse. However, these disorders may occasionally be a manifestation of RA, spondyloarthritis, gout and pseudogout. Effective management of athletes presenting with musculoskeletal complaints requires a structured history, physical examination, and definitive diagnosis to distinguish soft tissue problems from joint problems and an inflammatory syndrome from a non-inflammatory syndrome. Clues to a systemic inflammatory aetiology may include constitutional symptoms, morning stiffness, elevated acute-phase reactants and progressive symptoms despite modification of physical activity. The mechanism of injury or lack thereof is also a clue to any underlying disease. In these circumstances, more complete workup is reasonable, including radiographs, magnetic resonance imaging and laboratory testing for autoantibodies.

  View details for Web of Science ID 000261404300003

  View details for PubMedID 18937522

• Intertester Reliability and Validity of Manual Spinal Segmental Motion Testing. Physical Therapy. Landel R, Kulig K, Li B, Fredericson M, Powers CM 2008; 88 (1): 43-9
• Patellofemoral Pain; In BMJ Clinical Evidence for Sports Medicine. London: BMJ Publishing Group Lee J, Fredericson M 2008
• Rheumatic diseases that mimic sports-related injuries. Muscle: From Embryology to Function Jennings F, Fredericson M 2008
• Essentials of Physical Medicine and Rehabilitation Frontera W, Silver J, Rizzo T Edition Fredericson M, Chew K 2008
• Core Stability Exercise Principles CURRENT SPORTS MEDICINE REPORTS Akuthota, V., Ferreiro, A., Moore, T., Fredericson, M. 2008; 7 (1): 39-44

  Abstract

  Core stability is essential for proper load balance within the spine, pelvis, and kinetic chain. The so-called core is the group of trunk muscles that surround the spine and abdominal viscera. Abdominal, gluteal, hip girdle, paraspinal, and other muscles work in concert to provide spinal stability. Core stability and its motor control have been shown to be imperative for initiation of functional limb movements, as needed in athletics. Sports medicine practitioners use core strengthening techniques to improve performance and prevent injury. Core strengthening, often called lumbar stabilization, also has been used as a therapeutic exercise treatment regimen for low back pain conditions. This article summarizes the anatomy of the core, the progression of core strengthening, the available evidence for its theoretical construct, and its efficacy in musculoskeletal conditions.

  View details for DOI 10.1097/01.CSMR.0000308663.13278.69

  View details for Web of Science ID 000207790800011

  View details for PubMedID 18296944

• iliotibial band syndrome; In BMJ Clinical Evidence for Sports Medicine. London: BMJ Publishing Group Mak J, Fredericson M 2008
• Rotator Cuff Injuries; In Handbook for Diagnosis and Treatment of Shoulder Disorders. Totowa, NJ: Humana Press Inc. Ben-Aviv D, Fredericson M 2008
• Regional bone mineral density in male athletes: a comparison of soccer players, runners and controls BRITISH JOURNAL OF SPORTS MEDICINE Fredericson, M., Chew, K., Ngo, J., Cleek, T., Kiratli, J., Cobb, K. 2007; 41 (10): 664-668

  Abstract

  To investigate the association of soccer playing and long-distance running with total and regional bone mineral density (BMD).Cross-sectional study.Academic medical centre.Elite male soccer players (n = 15), elite male long-distance runners (n = 15) and sedentary male controls (n = 15) aged 20-30 years.BMD (g/cm2) of the lumbar spine (L1-L4), right hip, right leg and total body were assessed by dual-energy x-ray absorptiometry, and a scan of the right calcaneus was performed with a peripheral instantaneous x-ray imaging bone densitometer.After adjustment for age, weight and percentage body fat, soccer players had significantly higher whole body, spine, right hip, right leg and calcaneal BMD than controls (p = 0.008, p = 0.041, p<0.001, p = 0.019, p<0.001, respectively) and significantly higher right hip and spine BMD than runners (p = 0.012 and p = 0.009, respectively). Runners had higher calcaneal BMD than controls (p = 0.002). Forty percent of the runners had T-scores of the lumbar spine between -1 and -2.5. Controls were similar: 34% had T-scores below -1 (including 7% with T-scores lower than -2.5).Playing soccer is associated with higher BMD of the skeleton at all sites measured. Running is associated with higher BMD at directly loaded sites (the calcaneus) but not at relatively unloaded sites (the spine). Specific loading conditions, seen in ball sports or in running, play a pivotal role in skeletal adaptation. The importance of including an appropriate control group in clinical studies is underlined.

  View details for DOI 10.1136/bjsm.2006.030783

  View details for Web of Science ID 000249621100015

  View details for PubMedID 17473003

• Sacral stress fractures: Magnetic resonance imaging not always definitive for early stage injuries - A report of 2 cases AMERICAN JOURNAL OF SPORTS MEDICINE Fredericson, M., Moore, W., Biswal, S. 2007; 35 (5): 835-839

  View details for DOI 10.1177/0363546506296519

  View details for Web of Science ID 000246264600019

  View details for PubMedID 17261568

• Segmental Lumbar Mobility in Individuals with Central Low Back Pain: In Vivo Assessment During Passive and Active Motion Using Dynamic MRI. BMC Musculoskeletal Disorders Kulig K, Powers CM, Landel R, Chen K, Fredericson M, Guilett M, Butts K 2007; 8 (8)
• Current Evidence and Clinical Application of Knee Braces. American Journal of Physical Medicine Chew K, Lew H, Date E, Fredericson M 2007; 86: 678-686
• Is cartilage thickness different in young subjects with and without patellofemoral pain? OSTEOARTHRITIS AND CARTILAGE Draper, C. E., Besier, T. F., Gold, G. E., Fredericson, M., Fiene, A., Beaupre, G. S., Delp, S. L. 2006; 14 (9): 931-937

  Abstract

  To determine the differences in load-bearing patellofemoral joint cartilage thickness between genders. To determine the differences in load-bearing cartilage thickness between pain-free controls and individuals with patellofemoral pain.The articular cartilage thickness of the patella and anterior femur was estimated from magnetic resonance images in 16 young, pain-free control subjects (eight males, eight females) and 34 young individuals with patellofemoral pain (12 males, 22 females). The average age of all subjects was 28+/-4 years. The cartilage surfaces were divided into regions approximating the location of patellofemoral joint contact during knee flexion. The mean and peak cartilage thicknesses of each region were computed and compared using a repeated-measures Analysis of Variance.On average, males had 22% and 23% thicker cartilage than females in the patella (P < 0.01) and femur (P < 0.05), respectively. Male control subjects had 18% greater peak patellar cartilage thickness than males with patellofemoral pain (P < 0.05); however, we did not detect differences in patellar cartilage thickness between female control subjects and females with patellofemoral pain (P = 0.45). We detected no significant differences in femoral cartilage thickness between the control and pain groups.Thin cartilage at the patella may be one mechanism of patellofemoral pain in male subjects, but is unlikely to be a dominant factor in the development of pain in the female population.

  View details for DOI 10.1016/j.joca.2006.03.006

  View details for Web of Science ID 000239898500012

  View details for PubMedID 16647278

• Synovial chondromatosis in an elite cyclist: A case report ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION Doward, D. A., Troxell, M. L., Fredericson, M. 2006; 87 (6): 860-865

  Abstract

  Primary synovial chondromatosis is a rare disorder that can present as chronic hip and groin pain. It is characterized by formation of osteocartilaginous nodules arising from the synovium. We report the first case, to our knowledge, of an Olympic-caliber cyclist, in her mid thirties, with primary synovial chondromatosis of the left hip. Clinical examination showed decreased internal rotation, external rotation, forward flexion, and abduction of the left hip. A radiograph of the left hip showed slight hip-joint narrowing centrally. A magnetic resonance imaging arthrogram showed a small anterior labral tear and innumerable small intermediate-intensity filling defects situated diffusely within the joint fluid. Fluoroscopically guided injection of the left hip with local anesthetic and cortisone produced temporary pain relief. Conservative treatment was marginally helpful. Results of a rheumatology workup were unremarkable. Arthroscopic removal of loose bodies and synovectomy were performed. The diagnosis of primary synovial chondromatosis was confirmed by histologic examination. At the 17-month follow-up, our patient was essentially pain free and had returned to her previous athletic activities.

  View details for DOI 10.1016/j.apmr.2006.02.030

  View details for Web of Science ID 000238203100017

  View details for PubMedID 16731223

• Injury to the deep motor branch of the ulnar nerve during hook of hamate excision ORTHOPEDICS Fredericson, M., Kim, B., Date, E. S., McAdams, T. R. 2006; 29 (5): 456-458

  View details for Web of Science ID 000237773300015

  View details for PubMedID 16729750

• The Evaluation of Patellofemoral Pain in the Clinic: Do Clinical Measures Predict Dynamic Gait Measures? Simons, N., Fredericson, M., Besier, T., Beaupre, G., Delp, S., Butler, E. LIPPINCOTT WILLIAMS & WILKINS. 2006: S64-S65

  View details for Web of Science ID 000208070800259

• Practical management of lliotibial band friction syndrome in runners CLINICAL JOURNAL OF SPORT MEDICINE Fredericson, M., Weir, A. 2006; 16 (3): 261-268

  Abstract

  This article outlines the practical management of iliotibial band friction syndrome (ITBFS) in running athletes. ITBFS is the most common cause of lateral knee pain in runners and is related to repetitive friction of the iliotibial band sliding over the lateral femoral epicondyle. Runners predisposed to this injury are typically in a phase of over training and often have underlying weakness of the hip abductor muscles. The diagnosis of ITBFS is clinical and is based on a thorough patient history and physical exam. In the acute phase, treatment includes activity modification, ice, nonsteroidal anti-inflammatory medication, and corticosteroid injection in cases of severe pain or swelling. During the subacute phase emphasis is on stretching of the iliotibial band and soft tissue therapy for any myofascial restrictions. The recovery phase focuses on a series of exercises to improve hip abductor strength and integrated movement patterns. The final return to running phase is begun with an every other day program, starting with easy sprints and avoidance of hill training with a gradual increase in frequency and intensity. In rare refractory cases that do not respond to conservative treatment, surgery can be considered.

  View details for Web of Science ID 000238136600013

  View details for PubMedID 16778549

• Physical examination and patellofemoral pain syndrome AMERICAN JOURNAL OF PHYSICAL MEDICINE & REHABILITATION Fredericson, M., Yoon, K. S. 2006; 85 (3): 234-243

  Abstract

  Patellofemoral pain syndrome, which accounts for 25% of all sports-related knee injuries, is multifactorial in origin. A combination of variables, including abnormal lower limb biomechanics, soft-tissue tightness, muscle weakness, and excessive exercise, may result in increased cartilage and subchondral bone stress, patellofemoral pain, and subtle or more overt patellar maltracking. Because of the multiple forces affecting the patellofemoral joint, the clinical evaluation and treatment of this disorder is challenging. An extensive search of the literature revealed no single gold-standard test maneuver for that disorder, and the reliability of the maneuvers described was generally low or untested. An abnormal Q-angle, generalized ligamentous laxity, hypomobile or hypermobile tenderness of the lateral patellar retinaculum, patellar tilt or mediolateral displacement, decreased flexibility of the iliotibial band and quadriceps, and quadriceps, hip abductor, and external rotator weakness were most often correlated with patellofemoral pain syndrome.

  View details for DOI 10.1097/01.phm.0000200390.67408.f0

  View details for Web of Science ID 000235569200008

  View details for PubMedID 16505640

• An intervention program to reduce hamstring injuries. Physician and sportsmedicine Fredericson, M. 2005; 33 (12): 8-?

  View details for DOI 10.3810/psm.2005.12.266

  View details for PubMedID 20086342

• Normalization of bone density in a previously amenorrheic runner with osteoporosis MEDICINE AND SCIENCE IN SPORTS AND EXERCISE Fredericson, M., Kent, K. 2005; 37 (9): 1481-1486

  Abstract

  To examine changes in bone mineral density (BMD) and bone mineral content (BMC) in relation to pharmacological and nutritional interventions in a distance runner diagnosed with the female athlete triad of disordered eating, amenorrhea, and osteoporosis.BMD of the lumbar spine (L2-L4) and total proximal femur were measured from ages 22.9 to 30.8 yr using dual x-ray absorptiometry (DXA).At age 22.9, the patient presented with primary amenorrhea, low body weight (BMI: 15.8 kg.m(-2)), and low BMD in the spine (74% of normal, T score: -2.50) and hip (80% of normal, T score: -1.54). For the next 2 yr, the patient took oral contraceptives to induce menses, but continued to maintain a low weight. Her BMD remained unchanged. At age 25.1 yr, she decided to gain weight and improve her nutrition, resulting in small increases in spinal BMD (+1.1%), hip BMD (+1.6%), and total body BMC (+7.6%) in 4 months. From ages 25.4 to 30.8 yr, the patient continued to gain weight, eventually reaching a healthy BMI of 21.3 kg.m(-2); correspondingly, since baseline, her BMD had increased 25.5% in the spine and 19.5% in the hip, bringing her BMD to within normal values (spine: 94% of normal, hip: 96% of normal).This case illustrates that even if skeletal development is interrupted in adolescence, there is still the potential for "catch-up" in BMD well into the third decade of life. Reversal of large bone density deficits in this patient can be attributed to improved nutrition and weight gain but not to hormone replacement.

  View details for DOI 10.1249/01.mss.0000177561.95201.8f

  View details for Web of Science ID 000232078100005

  View details for PubMedID 16177598

• MRI findings of femoral diaphyseal stress injuries in athletes AMERICAN JOURNAL OF ROENTGENOLOGY Hwang, B., Fredericson, M., Chung, C. B., Beaulieu, C. F., Gold, G. E. 2005; 185 (1): 166-173

  View details for Web of Science ID 000229951900029

  View details for PubMedID 15972418

• Stress Fractures, In: Sports Medicine: Just the Facts Fredericson M, Editors: OConnor F, Wilder R, Sallis B 2005
• Muscular Balance, Core Stability, and Injury Prevention for Middle- and Long-Distance Runners. PM&R Clinics of North America Fredericson M, Moore T 2005; Vol 16 (3): 669-689
• The effect of axial loading and spine position on intervertebral disc hydration: An in vivo pilot study JOURNAL OF BACK AND MUSCULOSKELETAL REHABILITATION Lee, S. U., Fredericson, M., Butts, K., Lang, P. 2005; 18 (1-2): 15-20

  View details for Web of Science ID 000232937000003

• Spectrum of MRI findings in femoral diaphyseal stress injuries Hwang, B. J., Fredericson, M., Chung, C. B., Beaulieu, C., Gold, G. AMER ROENTGEN RAY SOC. 2005: 107-107

  View details for Web of Science ID 000228717800443

• Normalization of bone density in a previously amenorrheic runner with osteoporosis. Medicine & Science in Sports & Exercise (Accepted). Fredericson M, Kent K 2005; 37: 1481-1486
• Lower extremity stress fractures In: Sports Medicine: Board Review and Examination Fredericson M, Editors: OConnor F, Wilder R, Sallis B 2005
• Femoral diaphyseal stress fractures: results of a systematic bone scan and magnetic resonance imaging evaluation in 25 runners PHYSICAL THERAPY IN SPORT Fredericson, M., Jang, K. U., Bergman, G., Gold, G. 2004; 5 (4): 188-193

  View details for DOI 10.1016/j.ptsp.2004.05.004

  View details for Web of Science ID 000225502900005

• Asymptomatic tibial stress reactions: MRI detection and clinical follow-up in distance runners AMERICAN JOURNAL OF ROENTGENOLOGY Bergman, A. G., Fredericson, M., Ho, C., Matheson, G. O. 2004; 183 (3): 635-638

  Abstract

  The purpose of this study was twofold: to determine if asymptomatic elite distance runners exhibit stress reactions of the tibia on MR images and to determine if the presence of bone stress lesions predicts later development of symptomatic tibial stress injuries.Signs of a tibial stress reaction were found on MRI in 43% of the 21 asymptomatic college distance runners in this study. The presence of these changes was not found to be a predictor of future tibial stress reactions or stress fractures. Our findings underscore the importance of correlating MRI findings with clinical findings before making therapeutic decisions.

  View details for Web of Science ID 000223578100018

  View details for PubMedID 15333349

• Disabling foot cramping in a runner secondary to paramyotonia congenita: A case report FOOT & ANKLE INTERNATIONAL Fredericson, M., Kim, B. J., Date, E. S. 2004; 25 (7): 510-512

  Abstract

  An 18-year-old male runner was referred to the authors' clinic with a 1-year history of cramping left foot pain. His symptoms developed insidiously when he increased his training, with an onset of severe left foot pain and tightness that would develop after about 20 minutes of exercise. The more he continued to run, the more the symptoms were aggravated and evolved to the toes curling with intrinsic muscle spasm. This symptom was easily provoked when he was exposed to cold temperature. A family history of similar symptoms was revealed in his sister and uncle. Physical examination including neurologic examination was normal. Diagnostic workup revealed generalized myotonia. According to the history, physical examination, and diagnostic workup, his diagnosis was considered to be most compatible to paramyotonia congenita. He was given phenytoin, which lessened his symptoms and allowed him to continue running with minimal symptoms, but he stopped running because he was not able to maintain mileage high enough to compete successfully.

  View details for Web of Science ID 000223886000012

  View details for PubMedID 15319111

• Intermittent normbaric hypoxia does not alter performance or erythropoietic markers in highly trained distance runners Journal of Applied Physiology Julian CG, Gore CJ, Wilbur RL, Daniels JT, Fredericson M, Stray-Gunderson J, Hahn AG, Levine BD 2004; 96 (5): 1800-7
• Femoral Diaphyseal Stress Fractures: Results of a Systematic Bone Scan and Magnetic Resonance Imaging Evaluation in 26 Runners. Physical Therapy &Sport Fredericson M, Jang K, Bergman G, Gold G 2004
• Spine pain: Aquatic rehabilitation strategies. In: Comprehensive Aquatic Therapy 2nd Edition Cole AJ, Fredericson M, Johnson JN, Moschetti M, Eagleston R, Stratton S 2004
• Patellofemoral kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella: A preliminary study JOURNAL OF ORTHOPAEDIC & SPORTS PHYSICAL THERAPY Powers, C. M., Ward, S. R., Fredericson, M., Guillet, M., Shellock, F. G. 2003; 33 (11): 677-685

  Abstract

  Single-group, repeated-measures design.To compare patellofemoral joint kinematics during weight-bearing and non-weight-bearing knee extension in persons with lateral subluxation of the patella.The only previous study to quantify differences in patellofemoral joint kinematics during weight-bearing and non-weight-bearing tasks was limited in that static loading conditions were utilized. Differences in patellofemoral joint kinematics between weight-bearing and non-weight-bearing conditions have not been quantified during dynamic movement.Six females with a diagnosis of patellofemoral pain and lateral subluxation of the patella participated. Using kinematic magnetic resonance imaging, axial images of the patellofemoral joint were obtained as subjects extended their knee from 45 degrees to 0 degrees during non-weight-bearing (5% body weight resistance) and weight-bearing (unilateral squat) conditions. Measurements of patellofemoral joint relationships (medial/lateral patellar displacement and patellar tilt), as well as femur and patella rotations relative to an external reference system (ie, the image field of view), were obtained at 3 degrees increments during knee extension.During non-weight-bearing knee extension, lateral patellar displacement was more pronounced than during the weight-bearing condition between 30 degrees and 12 degrees of knee extension, with statistical significance being reached at 27 degrees, 24 degrees, and 21 degrees. No differences in lateral patellar tilt were observed between conditions (P = .065). During the weight-bearing condition, internal femoral rotation was significantly greater than during the non-weight-bearing condition as the knee extended from 18 degrees to 0 degrees. During the non-weight-bearing condition, the amount of lateral patellar rotation was significantly greater than during the weight-bearing condition throughout the range of motion tested.The results of this study demonstrated that lateral patellar displacement was more pronounced during non-weight-bearing knee extension compared to weight-bearing knee extension in persons with lateral patellar subluxation. In addition, the results of this investigation suggest that the patellofemoral joint kinematics during non-weight-bearing could be characterized as the patella rotating on the femur, while the patellofemoral joint kinematics during the weight-bearing condition could be characterized as the femur rotating underneath the patella.

  View details for Web of Science ID 000186785000006

  View details for PubMedID 14669963

• Differential diagnosis of leg pain in the athlete JOURNAL OF THE AMERICAN PODIATRIC MEDICAL ASSOCIATION Fredericson, M., Wun, C. 2003; 93 (4): 321-324

  Abstract

  Leg pain in the athlete is common and has many different etiologies. The most common causes include muscle or tendon injury, medial tibial stress syndrome, stress fracture, and exertional compartment syndrome. Less common causes of leg pain include lumbosacral radiculopathy, lumbosacral spinal stenosis, focal nerve entrapment, vascular claudication from atherosclerosis, popliteal artery entrapment syndrome, and venous insufficiency. This article reviews the essential history and physical examination findings and the various causes of leg pain to help the clinician pinpoint the diagnosis and facilitate the athlete's return to sport participation.

  View details for Web of Science ID 000184335500011

  View details for PubMedID 12869603

• Sacral stress fractures - Tracking down nonspecific pain in distance runners PHYSICIAN AND SPORTSMEDICINE Fredericson, M., Salamancha, L., Beaulieu, C. 2003; 31 (2): 31-?

  Abstract

  Sacral stress fractures are an underrecognized cause of low-back and gluteal pain in distance runners. The combination of low bone density and increased activity blurs the boundary between fatigue and insufficiency fractures in many runners. MRI is the preferred radiologic technique because of its ability to localize the site of injury and rule out tumors, disk disease, or sacroiliitis. By identifying the condition early, clinicians contribute to a favorable outcome and help most athletes return to full activity in 12 to 14 weeks.

  View details for Web of Science ID 000180861500007

  View details for PubMedID 20086455

• Swimming biomechanics and injury prevention - New stroke techniques and medical considerations PHYSICIAN AND SPORTSMEDICINE Johnson, J. N., Gauvin, J., Fredericson, M. 2003; 31 (1): 41-46

  Abstract

  Shoulder injuries are common in swimmers of all ages and abilities. Advances in the understanding of biomechanics help identify and correct stroke flaws to prevent shoulder injury. Physicians can demonstrate correct pull patterns and body alignment in an office setting, and proper coaching can help correct mistakes made in the water. If injury occurs, swimmers can employ rehabilitation techniques, including preventive scapular stabilization exercises, to prevent recurrence. The treating physician and physical therapist who understand stroke technique and prevention concepts may help decrease the incidence of swimming-related shoulder injuries.

  View details for Web of Science ID 000180257100012

  View details for PubMedID 20086441

• The effect of axial loading and spine position on intervertebral disc hydration: an in vivo pilot study. Journal of Back and Musculoskeletal Rehabilitation (In Press). Lee S, Fredericson M, Lang P 2003; 74: 512-516
• An Unusual Cause of Ischemic Claudication. Archives of Physical Medicine Rehabilitation Fredericson M, Waite B 2003; 84: 766-768
• Foot pain in a runner. American Academy of PM&R Musculoskeletal On-Line Case No. 12 Fredericson M, Kim BJ 2003; August
• Swimming biomechanics and injury prevention. Physician and Sports Medicine Johnson J, Gauvin J, Fredericson M 2003; 31 (1): 41-48..
• Lumbar spine disc heights and curvature: Upright posture vs. supine compression harness. Aviation and Space Environment Medicine Lee S, Hargens A, Fredericson M, Lang P 2003; 74: 512-516
• Stronger shoulders for swimmers PHYSICIAN AND SPORTSMEDICINE Johnson, J. N., Gauvin, J., Fredericson, M. 2003; 31 (1): 47-48

  Abstract

  Strong shoulders are essential for competitive swimmers, who make as many as 1 million shoulder rotations per week while training. It's no surprise that shoulder pain is common, but four simple exercises can help you prevent much of the discomfort. Please check with your doctor before beginning these exercises if you are currently injured.

  View details for Web of Science ID 000180257100013

  View details for PubMedID 20086442

• Quantitative analysis of the relative effectiveness of 3 iliotibial band stretches ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION Fredericson, M., White, J. J., MacMahon, J. M., Andriacchi, T. P. 2002; 83 (5): 589-592

  Abstract

  To compare the relative effectiveness of 3 common standing stretches for the iliotibial band (ITB): arms at side (stretch A), arms extending overhead (stretch B), and arms reaching diagonally downward (stretch C).Each subject's biomechanics was captured as a 3-dimensional image by using a 4-camera gait acquisition system with a forceplate.University biomotion laboratory.Five male elite-level distance runners.All participants performed each of the 3 standing stretches for the ITB.For each stretch, change in ITB tissue length and the force generated within the stretched complex was measured. Data were then combined and analyzed by using kinetic values assessment.All 3 stretches created statistically significant changes in ITB length (P<.05), but stretch B, incorporating overhead arm extension, was consistently most effective both for average ITB length change and average adduction moments at the hip and knee.Adding an overhead arm extension to the most common standing ITB stretch may increase average ITB length change and average external adduction moments in elite-level distance runners.

  View details for DOI 10.1053/apmr.2002.31606

  View details for Web of Science ID 000175494000001

  View details for PubMedID 11994795

• Sacroiliac joint pain syndrome in active patients: A look behind the pain. Physician and Sports Medicine Chen Y, Fredericson M, Smuck M 2002; 11: 30-37.
• Utilization of medical acupuncture at the Stanford Complementary Medicine Clinic: A two-year retrospective study. Medical Acupuncture Fredericson M, Pun S, Nelson L, Spiegel D 2002; 14: 36-39.
• Practical management of patellofemoral pain CLINICAL JOURNAL OF SPORT MEDICINE Fredericson, M., Powers, C. M. 2002; 12 (1): 36-38

  View details for Web of Science ID 000173820100009

  View details for PubMedID 11854587

• Lateral planter nerve entrapment in a competitive gymnast CLINICAL JOURNAL OF SPORT MEDICINE Fredericson, M., Standage, S., Chou, L., Matheson, G. 2001; 11 (2): 111-114

  View details for Web of Science ID 000169055800008

  View details for PubMedID 11403110

• Medical acupuncture for the treatment of non-radicular low back pain: A preliminary investigation of a treatment protocol and outcome measures. Medical Acupuncture Fredericson M, Guisto J 2001; 13: 16-19.
• Patellofemoral Pain Syndrome In: Textbook of Running Medicine. New York: The McGraw Hill Companies Fredericson M, Editors: Wilder R, OConnor F 2001
• Peripatellar Pathologies In: Textbook of Running Medicine. New York: The McGraw Hill Companies Fredericson M, Editors: Wilder R, OConnor F 2001
• Changes in posterior disc bulging and intervertebral foraminal size associated with flexion-extension movement: a comparison between L4-5 and L5-S1 levels in normal subjects. spine journal Fredericson, M., Lee, S. U., Welsh, J., Butts, K., Norbash, A., Carragee, E. J. 2001; 1 (1): 10-17

  Abstract

  No previous study has used magnetic resonance imaging (MRI) to evaluate changes of posterior disc bulging and intervertebral foraminal size in the normal spine with flexion-extension movement, comparing L4-5 versus L5-S1 intervertebral levels.To determine changes in posterior disc bulging and intervertebral foraminal size with flexion-extension movement, comparing L4-5 versus L5-S1 intervertebral levels.An in vivo study of magnetic resonance kinematics with spine flexion extension.Spines of three volunteers with no history of low back pain were scanned in neutral, flexion, and extension positions in a vertically open MRI system. MRI was repeated after 6 hours of normal activity and an additional 4 hours of heavy activity with a weighted vest. Posterior bulging of the intervertebral disc and the size of intervertebral foramen were measured at the L4-5 and L5-S1 levels.With spine flexion, posterior bulging of the discs increased at L4-5 in eight of nine measurements (three different spine-loading states for each of three subjects) and L5-S1 discs in six of nine measurements. In most cases, posterior bulging decreased with extension. No significant difference was noted in the degree of disc bulge between levels. Foraminal size at L4-5 increased with flexion and decreased with extension, and the extent of these changes was greater at the L4-5 level than at L5-S1.This pilot study demonstrates two distinct behavior characteristics of the normal spine with flexion-extension movement.

  View details for PubMedID 14588361

• Quick solutions for iliotibial band syndrome PHYSICIAN AND SPORTSMEDICINE Fredericson, M., Guillet, M., DeBenedictis, L. 2000; 28 (2): 53-?

  Abstract

  Though recognizing the sharp, burning lateral knee pain of iliotibial band syndrome isn't difficult, treating the condition can be a challenge because underlying myofascial restrictions can significantly contribute to the patient's pain and disability. The physical exam should include a thorough evaluation to identify tender trigger points as well as tenderness and possible swelling at the distal iliotibial band. After acute symptoms are alleviated with activity restriction and modalities, problematic trigger points can be managed with massage therapy or other treatments. A stepwise stretching and strengthening program can expedite patients' return to running.

  View details for Web of Science ID 000085197700006

  View details for PubMedID 20086621

• The differential diagnosis of heel pain in athletes. American Academy of PM&R Musculoskeletal On-Line Cases Fredericson M, Standage S, Chou L, Matheson G 2000; 3
• Quick solutions for iliotibial band syndrome Physician and Sports Medicine Fredericson M, Guillet M, DeBenedictis L 2000; 28: 52-68.
• Imaging: MR imaging spots runners' overuse injuries. Biomechanics Bergman AG, Fredericson M 2000; 11: 67-76
• MR imaging of stress reactions, muscle injuries, and other overuse injuries in runners. Magnetic resonance imaging clinics of North America Bergman, A. G., Fredericson, M. 1999; 7 (1): 151-?

  Abstract

  Running-related injuries are increasingly common, and most often due to overuse. This article briefly discusses the biomechanics of running, and a general review of stress lesions of bone; site-specific reviews of bony stress lesions and other running-related soft tissue injuries; and associated MR imaging findings.

  View details for PubMedID 10067229

• Shoulder MRI after impingement test injection SKELETAL RADIOLOGY Bergman, A. G., Fredericson, M. 1998; 27 (7): 365-368

  Abstract

  To determine how long injected fluid from an impingement test remains in the bursa or adjacent soft tissues after an injection.Six patients prospectively underwent MRI of the shoulder immediately before and after an impingement test injection, and at 3 days, 2 weeks and 4 weeks later. MR images were evaluated and graded for fluid distribution within the bursa and adjacent soft tissues. The rotator cuff was evaluated for signal abnormalities related to the injection.Three days after the injection, the soft tissue fluid had returned to pre-injection levels or less in five of the six patients. No patients showed rotator cuff signal abnormalities related to the impingement test injection. We recommend a delay of 3 days before a shoulder MR examination after an injection has been performed, to avoid misinterpretations.

  View details for Web of Science ID 000075308500003

  View details for PubMedID 9730326

• Stress fractures in athletes ORTHOPADE Fredericson, M., Bergman, A. G., Matheson, G. O. 1997; 26 (11): 961-971

  Abstract

  Stress fractures are one of the most common overuse injuries seen in athletes, accounting for up to 20% of all injuries presented to sports medicine clinics. Runners are particularly prone to these injuries, however, it is difficult to predict injury as there is usually a critical interplay between the athlete's biomechanical predisposition, training methods, and other factors such as diet, and muscle strength and flexibility. This article will discuss the key clinical findings for the majority of stress fractures encountered in a sports medicine practice. A classification scheme will also be described that will allow the clinician to make appropriate treatment decisions based on the degree of risk for each injury.

  View details for Web of Science ID A1997YK90000010

  View details for PubMedID 9490431

• Sacral stress fractures in long-distance runners CLINICAL JOURNAL OF SPORT MEDICINE Eller, D. J., Katz, D. S., Bergman, A. G., Fredericson, M., Beaulieu, C. F. 1997; 7 (3): 222-225

  View details for Web of Science ID A1997XP44000014

  View details for PubMedID 9262893

• Common injuries in runners: diagnosis, rehabilitation and prevention Sports Medicine Fredericson M 1996; 21: 49-72
• TIBIAL STRESS REACTION IN RUNNERS - CORRELATION OF CLINICAL SYMPTOMS AND SCINTIGRAPHY WITH A NEW MAGNETIC-RESONANCE-IMAGING GRADING SYSTEM AMERICAN JOURNAL OF SPORTS MEDICINE Fredericson, M., Bergman, A. G., Hoffman, K. L., Dillingham, M. S. 1995; 23 (4): 472-481

  Abstract

  Medial tibial pain in runners has traditionally been diagnosed as either a shin splint syndrome or as a stress fracture. Our work using magnetic resonance imaging suggests that a progression of injury can be identified, starting with periosteal edema, then progressive marrow involvement, and ultimately frank cortical stress fracture. Fourteen runners, with a total of 18 symptomatic legs, were evaluated and, within 10 days, referred for radiographs, a technetium bone scan, and a magnetic resonance imaging scan. In 14 of the 18 symptomatic legs, magnetic resonance imaging findings correlated with an established technetium bone scan grading system and more precisely defined the anatomic location and extent of injury. We identified clinical symptoms, such as pain with daily ambulation and physical examination findings, including localized tibial tenderness and pain with direct or indirect percussion, that correlated with more severe tibial stress injuries. When clinically warranted, we recommend magnetic resonance imaging over bone scan for grading of tibial stress lesions in runners. Magnetic resonance imaging is more accurate in correlating the degree of bone involvement with clinical symptoms, allowing for more accurate recommendations for rehabilitation and return to impact activity. Additional advantages of magnetic resonance imaging include lack of exposure to ionizing radiation and significantly less imaging time than three-phase bone scintigraphy.

  View details for Web of Science ID A1995RJ94500018

  View details for PubMedID 7573660

• Patellofemoral pain in runners. Journal of Back & Musculoskeletal Rehabilitation Fredericson M 1995; 5: 305-316
• Diagnosing tibial stress injuries in athletes. West J Med. Fredericson M 1995; 162: 150
• Mediation of skin temperature biofeedback effects in children. Biofeedback and self-regulation Suter, S., Fredericson, M., Portuesi, L. 1983; 8 (4): 567-584

  Abstract

  Three studies are reported that, in general, fail to replicate an earlier investigation by this laboratory ( Suter & Loughry - Machado , 1981) in which impressive self-regulation of skin temperature by children was obtained. Mediation of skin temperature biofeedback effects is discussed. It is concluded that biofeedback self-regulation cannot be understood independently of the interpersonal, attitudinal, and cognitive context in which it occurs.

  View details for PubMedID 6675732