High rates of respiratory illnesses upon arrival: lessons from Team USA at the Santiago 2023 Pan American and Parapan American Games.

OBJECTIVE: To describe the incidence and characteristics of injuries and illnesses among Team USA athletes competing at the Santiago 2023 Pan American Games (PAG) and Parapan American Games (PPAG), with a particular focus on the incidence of respiratory illnesses and on injuries for sports new to the Olympic and Paralympic programmes. METHODS: Illnesses and injuries occurring among the 870 Team USA athletes competing in the Santiago 2023 PAG or PPAG were documented within Team USA's Injury and Illness Surveillance system. Illness and injury incidence per 1000 athlete-days (ADs) and incidence ratios (IR) were calculated, both with 95% CIs. RESULTS: Illness (IR 2.5, 95% CI 1.6, 3.9) and injury (IR 1.8, 95% CI 1.3, 2.5) rates were greater during PPAG compared with PAG. Illness rates were higher in the pre-opening ceremony period compared with the competition period for both PAG (IR 2.7, 95% CI 1.1, 5.9) and PPAG (IR 1.9, 95% CI 0.9, 3.8). Respiratory illness was the most common illness with 3.2% and 8.9% of all Team USA athletes reporting a respiratory illness during the PAG and PPAG, respectively. Sports that are relatively new to the Olympic/Paralympic programmes exhibited the highest injury rates during the Games: breaking (250.0 (91.7, 544.2) per 1000 ADs), Para taekwondo (93.8 (19.3, 274.0) per 1000 ADs) and surfing (88.9 (24.2, 227.6) per 1000 ADs). CONCLUSION: Respiratory illness rates were the most common type of illness during both PAG and PPAG and were more likely to occur prior to competition starting. Our data have identified high injury risk populations (breaking, surfing, Para taekwondo) and timing (pre-opening ceremony period) for further risk factor analysis.

Analysis of the Sport Mental Health Assessment Tool 1 (SMHAT-1) in Team USA athletes.

OBJECTIVE: The Sport Mental Health Assessment Tool 1 (SMHAT-1) was introduced as a critical component to the athlete health evaluation. However, the effectiveness of the initial triage step questionnaire (Athlete Psychological Strain Questionnaire (APSQ)) has yet to be analysed within a National Olympic and Paralympic Committee delegation. This study evaluated the ability of the APSQ to identify athletes at risk for mental health concerns. METHODS: Athletes completed the APSQ and all subsequent screening questionnaires of the SMHAT-1 as part of their Tokyo and Beijing Olympic and Paralympic Games health history screening. Each questionnaire was scored according to published guidelines, and the false-negative rate (FNR) for the APSQ identifying athletes that were positively screened on the subsequent questionnaires was computed. RESULTS: 1066 athletes from 51 different Olympic and Paralympic and Summer and Winter sports completed the SMHAT-1. The FNRs for all athletes who were positively screened on a subsequent questionnaire with an APSQ score of <17 ranged from 4.8% to 66.7%. The global FNR for being positively screened on any questionnaire was 67.5%. Female, Paralympic and Winter athletes scored higher on one or more questionnaires compared with male, Olympic and Summer athletes, respectively (p<0.05). CONCLUSION: Due to the high FNR of the APSQ detecting a potential mental health concern, we recommend athletes complete the APSQ and all subsequent questionnaires of the SMHAT-1 rather than using only the APSQ as an initial screening test.

Team USA injury and illness incidence at the 2022 Beijing Winter Olympic and Paralympic Games.

OBJECTIVE: The purpose of this study was to determine the injury and illness incidence from Team USA athletes from the 2022 Beijing Winter Olympic and Paralympic Games and assess any sex-based differences or differences between Olympic and Paralympic athletes. METHODS: Team USA Olympic (n=231, 48.5% female) and Team USA Paralympic (n=63, 22.2% female) athletes had medical encounters documented during the Games. Injuries and illnesses were defined according to the 2020 International Olympic Committee Consensus Statement and reviewed for accuracy by a physician. Incidence rates were calculated per 1000 athlete-days and further analysed by sex, sport, anatomical location, type of illness, injury event and injury mechanism, with incident rate ratios (IRRs) used for group comparisons. RESULTS: There were no differences in illness (Olympic illness, IRR=0.99 (95% CI 0.48 to 2.07), p=0.998; Paralympic illness, IRR=1.43 (95% CI 0.41 to 4.97), p=0.572) or injury rates (Olympic injury, IRR=0.63 (95% CI 0.39 to 1.03), p=0.062; Paralympic injury, IRR=1.01 (95% CI 0.43 to 2.35), p=0.988) between male and female (reference group) athletes. However, Olympic athletes had significantly lower illness (IRR=0.41 (95% CI 0.22 to 0.76), p=0.003) and injury (IRR=0.56 (95% CI 0.37 to 0.87), p=0.009) risks compared with Paralympic athletes. CONCLUSION: No significant sex-related differences in injury or illness were detected in Team USA Olympic or Paralympic participating in the 2022 Beijing Winter Games. However, Paralympic athletes exhibited higher rates of injury and illness compared with their Olympic counterparts. This study highlights delegation-specific epidemiological data which may facilitate more focused approaches for injury and illness prevention.

Recommended Musculoskeletal and Sports Ultrasound Terminology: A Delphi-Based Consensus Statement.

OBJECTIVES: The current lack of agreement regarding standardized terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice, and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. METHODS: A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus which was defined as group level agreement >80%. RESULTS: Content was organized into seven general topics including: 1) General Definitions, 2) Equipment and Transducer Manipulation, 3) Anatomic and Descriptive Terminology, 4) Pathology, 5) Procedural Terminology, 6) Image Labeling, and 7) Documentation. Terms and definitions which reached consensus agreement are presented herein. CONCLUSIONS: The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients, and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

American Medical Society for Sports Medicine sports ultrasound curriculum for sports medicine fellowships.

Sports ultrasound is commonly used by sports medicine physicians to enhance diagnostic and procedural accuracy. This expert consensus statement serves as an update to the 2015 American Medical Society for Sports Medicine recommended sports ultrasound curriculum for sports medicine fellowships. Although written in the context of the American sports medicine fellowship training model, we present a stepwise progression in both diagnostic and interventional sports ultrasound that may be applicable to the broader sports medicine community. The curriculum is divided into 12 units with each unit including didactic instructional sessions, practical hands-on instruction, independent scanning practice sessions and mentored clinical experience. To assist with prioritisation of learning, we have organised relevant pathology and procedures as essential, desirable and optional The expanded content can serve as an outline for continuing education postfellowship or for any physician to further advance their sports ultrasound knowledge and skill. We also provide updated scanning protocols, sample milestones and a sample objective structured clinical examination to aid fellowships with implementation of the curriculum and ongoing assessment of fellow progress.

Recommended musculoskeletal and sports ultrasound terminology: a Delphi-based consensus statement.

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Radiological Prevalence of Popliteal Artery Entrapment in Individuals With Anterior Leg Compartment Chronic Exertional Compartment Syndrome.

OBJECTIVE: Determine the radiological prevalence of popliteal artery entrapment (PAE) in subjects with anterior leg compartment chronic exertional compartment syndrome (CECS). DESIGN: Retrospective review. SETTING: Tertiary care center. PATIENTS: Of 71 patients diagnosed with anterior leg compartment CECS using an in-scanner exercise-based magnetic resonance imaging (MRI), 64 also completed Fast Imaging Employing Steady-State Acquisition (FIESTA) imaging. INTERVENTIONS: Electronic health records of patients diagnosed with anterior leg compartment CECS using an in-scanner exercise-based MRI between 2009 and 2018 were reviewed. MAIN OUTCOME MEASURES: Demographics, symptom laterality, and results of vascular work-up. RESULTS: Magnetic resonance imaging was positive for PAE in 33 of 64 (51.6%). Vascular evaluation was performed in 30 of 33 (90.9%). Of these 30, ankle-brachial indices (ABIs) with PAE maneuvers were performed in 29 (96.7%) and positive in 25 (86.2%). Pre-exercise and post-exercise ABIs were performed in 29 (96.7%) and abnormal in 20 (69.0%). Thirteen arterial duplex ultrasounds were performed; 10 were consistent with PAE (76.9%). An MR angiogram was performed in 8 (26.7%) and consistent with PAE in all. One computed tomography angiogram (3.3%) was completed and was normal. Overall, one or more tests were positive for PAE in all 30 with vascular evaluation. CONCLUSIONS: The radiological prevalence of PAE and anterior leg CECS was 51.6%. All subjects with vascular studies (90.9%) had one or more tests confirming radiological PAE. These findings suggest that the coexistence of PAE and CECS is common, and the PAE protocol used has a high correlation with vascular studies.

American Medical Society for Sports Medicine Position Statement: Principles for the Responsible Use of Regenerative Medicine in Sports Medicine.

ABSTRACT: Many sports medicine physicians are currently considering introducing regenerative medicine into their practice. Regenerative medicine and the subclassification of orthobiologics are a complicated topic and have produced widely varying opinions. Although there is concern by government regulators, clinicians, scientists, patient advocacy organizations, and the media regarding the use of regenerative medicine products, there is also excitement about the potential benefits with growing evidence that certain regenerative medicine products are safe and potentially efficacious in treating musculoskeletal conditions. Sports medicine physicians would benefit from decision-making guidance about whether to introduce orthobiologics into their practice and how to do it responsibly. The purpose of this position statement is to provide sports medicine physicians with information regarding regenerative medicine terminology, a brief review of basic science and clinical studies within the subclassification of orthobiologics, regulatory considerations, and best practices for introducing regenerative medicine into clinical practice. This information will help sports medicine physicians make informed and responsible decisions about the role of regenerative medicine and orthobiologics in their practice.

American Medical Society for Sports Medicine Sports Ultrasound Curriculum for Sports Medicine Fellowships.

ABSTRACT: Sports ultrasound is commonly used by sports medicine physicians to enhance diagnostic and procedural accuracy. This expert consensus statement serves as an update to the 2015 American Medical Society for Sports Medicine recommended sports ultrasound curriculum for sports medicine fellowships. Although written in the context of the American sports medicine fellowship training model, we present a stepwise progression in both diagnostic and interventional sports ultrasound that may be applicable to the broader sports medicine community. The curriculum is divided into 12 units with each unit including didactic instructional sessions, practical hands-on instruction, independent scanning practice sessions, and mentored clinical experience. To assist with prioritization of learning, we have organized relevant pathology and procedures as essential, desirable, and optional. The expanded content can serve as an outline for continuing education postfellowship or for any physician to further advance their sports ultrasound knowledge and skill. We also provide updated scanning protocols, sample milestones, and a sample objective structured clinical examination (OSCE) to aid fellowships with implementation of the curriculum and ongoing assessment of fellow progress.

Proceedings From the Ice Hockey Summit III: Action on Concussion.

OBJECTIVES: The Ice Hockey Summit III provided updated scientific evidence on concussions in hockey to inform these 5 objectives: (1) describe sport related concussion (SRC) epidemiology; (2) classify prevention strategies; (3) define objective, diagnostic tests; (4) identify treatment; and (5) integrate science and clinical care into prioritized action plans and policy. METHODS: Our action plan evolved from 40 scientific presentations. The 155 attendees (physicians, athletic trainers, physical therapists, nurses, neuropsychologists, scientists, engineers, coaches, and officials) voted to prioritize these action items in the final Summit session. RESULTS: To (1) establish a national and international hockey database for SRCs at all levels; (2) eliminate body checking in Bantam youth hockey games; (3) expand a behavior modification program (Fair Play) to all youth hockey levels; (4) enforce game ejection penalties for fighting in Junior A and professional hockey leagues; (5) establish objective tests to diagnose concussion at point of care; and (6) mandate baseline testing to improve concussion diagnosis for all age groups. CONCLUSIONS: Expedient implementation of the Summit III prioritized action items is necessary to reduce the risk, severity, and consequences of concussion in the sport of ice hockey.

The National Interscholastic Cycling Association Mountain Biking Injury Surveillance System: 40,000 Student-Athlete-Years of Data.

ABSTRACT: A web-based injury surveillance system was implemented through a collaboration between University of Utah researchers and the National Interscholastic Cycling Association (NICA) to better understand injury characteristics in mountain biking. Data were collected from NICA leagues during the 2018 and 2019 seasons. Injuries were tracked in 41,327 student-athlete-years, identifying 1750 unique injuries during 1155 injury events. Rider-dependent and rider-independent variables were analyzed. The most commonly reported injuries were concussion (23.6%), injuries to the wrist/hand (22.3%), and shoulder (15.6%). Half of all injury events occurred on downhills. Men and women reported similar yet significantly different injury rates (2.69% and 3.21%, respectively; P = 0.009). Women sustained more lower-limb injuries (37.8% vs 28.3%; P = 0.003). Nearly 50% of crashes resulted in an emergency room visit. Youth mountain bike racing is a rapidly growing sport. Acute traumatic injuries are common. Injury surveillance system data are now being used to inform injury prevention strategies and direct future research.

Ultrasound-Guided Fasciotomy for Chronic Exertional Compartment Syndrome: A Case Report.

Chronic exertional compartment syndrome (CECS) is characterized by an excessive increase in intracompartmental muscle pressures after exercise. Athletes with CECS report pain, pressure, and occasionally neurologic symptoms in the affected compartment during exercise that abates with rest. Although many treatment options have been proposed, athletes often require a fasciotomy to return to unrestricted sports participation. Surgical success rates vary; complications are not uncommon; and after surgery, it usually takes athletes 6 or more weeks to return to unrestricted impact activities. This case report describes a new ultrasound-guided fasciotomy technique for the treatment of anterior leg compartment CECS. The procedure required a 3 mm incision, was performed in the office under local anesthesia, and allowed the athlete to resume running within 1 week of the procedure. Although the preliminary results of this study are promising, further translational research is required before the widespread adoption of this procedure is recommended.

Ultrasound-Guided Cubital Tunnel Decompression in a Collegiate Swimmer: A Case Report.

A 19-year-old female collegiate swimmer presented to our sports medicine clinic with a history and physical examination consistent with right ulnar neuropathy at the cubital tunnel. Diagnostic ultrasound (US) revealed compression of the ulnar nerve under the cubital tunnel retinaculum (CTR) with nerve swelling proximal to the site of compression. Electrodiagnostic studies confirmed the diagnosis of a moderate to severe ulnar neuropathy at the elbow. Treatment consisted of an US-guided decompression of the ulnar nerve in the cubital tunnel by cutting the CTR using a rotated stylet "v" cutting technique. The patient's symptoms resolved, and she was able to begin a swimming progression 2 weeks after the procedure. After completion of this progression, she was able to successfully resume full, unrestricted competitive collegiate swimming without return of her symptoms. To the best of our knowledge, this is the first description of an US-guided cubital tunnel decompression surgery.

Can Ultrasound Identify Paradoxical Vocal Fold Movement? A Pilot Study.

OBJECTIVE: Vocal cord dysfunction (VCD) is characterized by paradoxical vocal fold movement (PVFM) during inspiration. The aim of this study was to determine whether ultrasound could accurately differentiate between normal and PVFM during respirations in a resting state. DESIGN: Prospective, single-subject design. SETTING: Academic medical center. PATIENTS: A speech-language pathologist who was able to volitionally alternate between normal and PVFM when breathing at rest was recruited to participate in the study. INTERVENTIONS: The subject was instructed to randomly alternate between normal and PVFM 20 times (10 times each). A single investigator imaged the vocal folds using ultrasound and reported when the subject alternated between the 2 respiratory states. MAIN OUTCOME MEASURES: The subject recorded when they changed between the 2 respiratory states, whether the investigator identified with the change occurred, and if the correct respiratory state was identified. RESULTS: The investigator recognized when the subject changed respiratory states and correctly identified the new respiratory state 100% of the time. CONCLUSIONS: The findings of the current study were promising and suggest that ultrasound may have utility in the diagnosis of VCD. However, because of the preliminary nature of these results, further research is required before recommending its clinical implementation.

Isolated meniscus extrusion associated with meniscotibial ligament abnormality.

PURPOSE: The purpose of this study was to describe meniscus extrusion, present imaging characteristics, and provide clinical correlations for patients with isolated meniscus extrusion. METHODS: Of the 3244 MRI reports identified as having meniscus extrusion, 20 patients were identified to have isolated meniscus extrusion (0.62%). Patients with moderate to severe chondromalacia, meniscus tears, intra-articular fractures, tumours, and ligament tears were excluded. Radiographs were reviewed and graded using Kellgren-Lawrence (K-L) scores. MRI's were reviewed for the extent of extrusion and whether or not the meniscotibial ligament was intact. Clinical presentation and management were recorded. RESULTS: The study population consisted of 12 females and 8 males with a mean age of 40.5, diagnosed with meniscus extrusion and minimal concomitant knee pathology. 68% of patients were considered symptomatic as their knee pain correlated with the side of their meniscus extrusion and no other reason for pain was identified. The mean amount of meniscus extrusion was 2.5 mm (SD ± 1.1 mm) with 45% (9 of 20) having 3 + mm of extrusion. Meniscotibial ligament abnormality was identified in 65% of cases (13 of 20). Patients with 3 + mm of meniscus extrusion were much more likely to have associated meniscotibial ligament abnormality (100%, 9 of 9) compared to those with < 3 mm of extrusion (36%, 4 of 11) (RR 2.75, p = 0.048). The mean K-L grade obtained at the initial visit was 0.9 (95% CI 0.7-1.4) and the mean K-L grade obtained on final follow-up was 1.3 (95% CI 0.8-2.8) (n.s.) at a mean of 44.7 months. No correlation was found between K-L grade, gender, age, acute injury, and BMI in relation to meniscotibial ligament abnormality or amount of meniscal extrusion. CONCLUSIONS: Meniscus extrusion often occurs in the presence of significant knee pathology, predominantly with meniscus tears or osteoarthritis. Isolated meniscus extrusion is a rare occurrence that may present clinically with knee pain, commonly to the side in which the extrusion occurs. In patients with three or more millimetres of meniscus extrusion, an intact meniscus and minimal knee pathology, meniscotibial ligament abnormality is likely. This may provide an opportunity to treat the meniscotibial ligament abnormality with meniscus centralisation technique and decrease the amount of meniscus extrusion.

Concussions in Ice Hockey - Moving Toward Objective Diagnoses and Point-of-care Treatment: A Review.

The incidence of sport-related concussion coupled with a doubling of the participation rate in youth hockey over the past two decades provides impetus for the review of the most promising concussion treatment options. This narrative review summarizes the future treatment options for sport-related concussions in ice hockey, while acknowledging their generalizability to concussion in all sports. Symptom assessment, sign observation, as well as cognitive and balance testing, have historically been used to diagnose a concussion. These methods continue to improve, but the need for effective treatments is clear. Pharmacologic, transcranial light, and nutritional supplement treatment options for concussion warranting further investigation have been identified. Dimethyl fumarate is an immunomodulatory compound thought to trigger antioxidant gene expression. Memantine reduces apoptosis and astrogliosis by inhibiting the calcium influx into cells normally caused by glutamate's activation of N-methyl-D-aspartate receptors. Thioredoxin-mimetic peptides and transcranial photobiomodulation temper the effects of the energy crisis by acting as free radical scavengers. In addition, seven neuroprotective nutritional supplements have been identified: berberine, creatine, curcumin, melatonin, omega-3 fatty acids, resveratrol, and vitamins. An estimated US $1.1 billion has been spent on unsuccessful traumatic brain injury clinical trials. As our ability to accurately diagnose concussion improves, dimethyl fumarate, memantine, thioredoxin-mimetic peptides, transcranial photobiomodulation, and nutritional supplements (berberine, creatine, curcumin, melatonin, omega-3 fatty acids, resveratrol, and vitamins) warrant further preclinical and clinical examination in advancing the treatment of sport-related concussions.

Increased stride-rate in runners following an independent retraining program: A randomized controlled trial.

PURPOSE: Increasing stride-rate by 5%-10% has been used for injury prevention and rehabilitation but evidence is limited if an independent program can alter stride-rate in runners. The objective of this study was to determine whether the preferred stride-rate of recreational runners can be increased by 5%-10% following a 6-week independent training program. METHODS: Thirty-eight runners running a minimum of 15 miles/wk with a preferred stride-rate ≤85 strides/min determined during treadmill testing were randomized into two groups: (a) Experimental group was instructed to increase stride-rate by 10% using a watch and foot pod for stride-rate feedback; and (b) Control group was instructed to continue normal running. Compliance was tracked with a training log. One stride being defined as two sequential steps. Preferred running stride-rate was retested at 6 weeks using the same testing protocol. RESULTS: There was no significant difference in baseline preferred running stride-rates between the experimental or control groups. A significant (P < .001) increase in stride-rate from 79.9 ± 4.8 to 86.8 ± 5.7 strides/min (8.6% increase) was found in the experimental group. The control group did not significantly change their stride-rate (Baseline: 80.4 ± 4.2, 6 weeks: 81.3 ± 3.3 strides/min). CONCLUSION: A 6-week home training program using a watch and foot pod can increase the preferred running stride-rate by 5%-10% in runners with a stride-rate of 85 or less. Clinicians may be able to apply this type of gait retraining in recreational runners when designing injury prevention and rehabilitation programs.

The King-Devick test in mixed martial arts: the immediate consequences of knock-outs, technical knock-outs, and chokes on brain functions.

The aim of this prospective cohort study was to determine the effect of an 'event,' defined as a knock-out (KO), technical knock-out (TKO), choke, or submission, on King-Devick (K-D) test times in mixed martial arts (MMA) athletes. MMA athletes (28.3 ± 6.6 years, n = 92) underwent K-D testing prior to and following a workout or match. Comparison of baseline and post-workout/match K-D times to assess any significant change. K-D tests worsened (longer) in a majority of athletes following an 'event' (N = 21) (49.6 ± 7.8 s vs 46.6 ± 7.8 s, p = 0.0156, Wilcoxon signed-rank test). K-D tests improved (shorter) following a standard workout or match in which no 'event' occurred in a majority of cases (n = 69) (44.2 ± 7.2 s vs 49.2 ± 10.9 s, p = <0.0001, Wilcoxon signed-rank test). Longer duration (worsening) of post-match K-D tests occurred in most athletes sustaining an 'event'; K-D tests shortened (improved) in a majority of athletes not sustaining an 'event'. Our study suggests MMA athletes suffering an 'event' may have sustained a brain injury similar to a concussion.

Variability of ischiofemoral space dimensions with changes in hip flexion: an MRI study.

OBJECTIVE: The primary aim of this study was to determine if ischiofemoral space (IFS) dimensions vary with changes in hip flexion as a result of placing a bolster behind the knees during magnetic resonance imaging (MRI). A secondary aim was to determine if IFS dimensions vary between supine and prone hip neutral positions. DESIGN: The study employed a prospective design. SETTING: Sports medicine center within a tertiary care institution. PARTICIPANTS: Five male and five female adult subjects (age mean = 29.2, range = 23-35; body mass index [BMI] mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. METHODS: An axial, T1-weighted MRI sequence of the pelvis was obtained of each subject in a supine position with their hips in neutral and flexed positions, and in a prone position with their hips in neutral position. Supine hip flexion was induced by placing a standard, 9-cm-diameter MRI knee bolster under the subject's knees. The order of image acquisition (supine hip neutral, supine hip flexed, prone hip neutral) was randomized. The IFS dimensions were then measured on a separate workstation. The investigator performing the IFS measurements was blinded to the subject position for each image. MAIN OUTCOME MEASUREMENTS: The main outcome measurements were the IFS dimensions acquired with MRI. RESULTS: The mean IFS dimensions in the prone position were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). In the supine hip neutral position, the IFS dimensions were 25.1 (SD 5.6) mm. The mean difference between the two positions of 3.15 (3.6) mm was statistically significant (95 % CI of the difference = 1.4 to 4.8 mm, t19 = 3.911, p = .001). The mean IFS dimensions in the hip flexed position were 36.9 (SD 5.7) mm. The mean difference between the two supine positions of 11.8 (4.1) mm was statistically significant (95 % CI of the difference = 9.9 to 13.7 mm, t19 = 12.716, p < .001). CONCLUSIONS: Our findings demonstrate that the IFS measurements obtained with MRI are dependent upon patient positioning with respect to hip flexion and supine versus prone positions. This finding has implications when evaluating for ischiofemoral impingement, an entity resulting in hip and/or buttock pain secondary to impingement of the quadratus femoris muscle within a pathologically narrowed IFS. One will need to account for patient hip flexion and supine versus prone positioning when evaluating individuals with suspected ischiofemoral impingement.