In Professional Male Soccer Players, Time-Loss Groin Injury Is More Associated With the Team Played for Than With Training/Match-Play Duration.

OBJECTIVE: To investigate the relationship between training/match-play duration and time-loss groin injury in professional male soccer players, and to determine whether previously identified intrinsic risk factors influenced this relationship. DESIGN: Prospective cohort study. METHODS: A total of 579 professional male soccer players were prospectively followed from July 2013 to June 2015. Time-loss groin injuries and individual training and match-play duration were recorded using standardized surveillance methods. Acute training/match-play duration and chronic training/match-play duration were considered as interacting variables. Nonlinear Cox regression analysis (modeled using restricted cubic splines), clustered by player identification number, examined the relationship between training/match-play duration and groin injury. Previously identified intrinsic risk factors of previous groin injury and eccentric adduction strength were included in the multivariable regression analysis. RESULTS: There was no clinically meaningful relationship between training/match-play duration and groin injury risk. Team played for had the strongest influence on groin injury risk (relative log hazard ratio -2.28 to 0.97). Groin injury risk was highest when accumulated chronic and acute training duration was also highest, but large confidence intervals indicate considerable uncertainty around this finding. Previous groin injury and eccentric adduction strength were not associated with groin injury risk when training/match-play duration and team were included in the model. CONCLUSION: In professional male soccer players, there was no clinically meaningful relationship between groin injury risk and training/match-play duration. Team played for either protected against or increased groin injury risk, indicating that team-related factors not measured in this study had greater effect on groin injury risk than training/match-play duration. J Orthop Sports Phys Ther 2022;52(4):217-223. Epub 5 Feb 2022. doi:10.2519/jospt.2022.10845.

Is Bony Hip Morphology Associated With Range of Motion and Strength in Asymptomatic Male Soccer Players?

Study Design Cross-sectional cohort study. Objectives To investigate the relationship between musculoskeletal screening findings and bony hip morphology in asymptomatic male soccer players. Background Athletes with femoroacetabular impingement (FAI) syndrome have cam and/or pincer morphology, pain on orthopaedic testing, and often reduced hip range of motion (ROM) and strength. However, cam and pincer morphology is also common in asymptomatic hips. Therefore, it is currently unknown whether the ROM and strength deficits observed in athletes with FAI syndrome result from the variance in their bony hip morphology or from their hip condition. Methods Male professional soccer players in Qatar were screened specifically for hip/groin pain in 2 consecutive seasons. The screening battery included pain provocation, ROM and strength tests, and hip radiographs. Univariate and multivariate regression analyses, using generalized estimating equations, evaluated the relationship between musculoskeletal screening findings and each bony hip morphological variant (cam, large cam, pincer, and acetabular dysplasia). Results Asymptomatic hips with cam and large cam morphology were associated with lower internal rotation ROM and bent-knee fall-out, and with a higher likelihood of pain on provocation testing. Pincer morphology was associated with lower abduction ROM and higher abduction strength. Acetabular dysplasia was associated with higher abduction ROM. Each association was weak and demonstrated poor or failed discriminatory power. Conclusion Bony hip morphology is associated with hip joint ROM and abduction strength, but musculoskeletal screening tests have a poor ability to discriminate between the different morphologies. J Orthop Sports Phys Ther 2018;48(4):250-259. doi:10.2519/jospt.2018.7848.

Musculoskeletal Screening Tests and Bony Hip Morphology Cannot Identify Male Professional Soccer Players at Risk of Groin Injuries: A 2-Year Prospective Cohort Study.

BACKGROUND: Musculoskeletal hip/groin screening tests are commonly performed to detect at-risk individuals. Bony hip morphology is considered a potential intrinsic risk factor but has not been examined prospectively. PURPOSE: To evaluate the association between intrinsic risk factors identified from musculoskeletal and radiographic screening tests and hip/groin injuries leading to time loss from training and/or match play in professional male soccer players. STUDY DESIGN: Prospective cohort study; Level of evidence, 2. METHODS: Male professional soccer players, aged ≥18 years, underwent screening specific for hip/groin pain during 2 consecutive seasons of the Qatar Stars League. The screening battery included pain provocation, range of motion, and strength tests as well as a hip radiographic examination. The radiographic examination included an anteroposterior pelvic view and 45° Dunn view, with bony hip morphology determined using quantitative methods. Time-loss (≥1 day) hip/groin injuries and individual player exposure (training and match play) were recorded prospectively, and injuries were categorized as adductor-related, inguinal-related, iliopsoas-related, pubic-related, or hip-related groin pain, or "other," as recommended in the Doha agreement. We calculated hazard ratios (HRs) from univariate and multivariate Cox regression models to assess the relationship between potential risk factors and hip/groin injuries. RESULTS: There were 438 players, completing 609 player seasons, and 113 hip/groin injuries that met the criteria for inclusion, with 85 injuries categorized as adductor-related. The proportion of players with bony morphological variants was the following: cam, 71%; pincer, 5%; and acetabular dysplasia, 13%. Previous hip/groin injuries (HR, 1.8; 95% CI, 1.2-2.7) and eccentric adduction strength were associated with the risk of hip/groin injuries. Higher (>1 SD above the mean) than normal eccentric adduction strength was associated with an increased risk for all hip/groin injuries (HR, 1.6; 95% CI, 1.0-2.5). Lower (<1 SD below the mean) than normal eccentric adduction strength was associated with an increased risk for adductor-related injuries (HR, 1.7; 95% CI, 1.0-3.0). No other musculoskeletal screening test or bony hip morphology variables were associated with the injury risk. CONCLUSION: Previous groin injuries and eccentric adduction strength were associated with the risk of groin injuries. However, these associations were not strong enough to identify an "at-risk" individual, and therefore, musculoskeletal screening tests were not useful to dictate individualized prevention strategies. Bony hip morphology was not associated with the risk of groin injuries.

Epidemiology of time loss groin injuries in a men's professional football league: a 2-year prospective study of 17 clubs and 606 players.

BACKGROUND/AIM: Groin injury epidemiology has not previously been examined in an entire professional football league. We recorded and characterised time loss groin injuries sustained in the Qatar Stars League. METHODS: Male players were observed prospectively from July 2013 to June 2015. Time loss injuries, individual training and match play exposure were recorded by club doctors using standardised surveillance methods. Groin injury incidence per 1000 playing hours was calculated, and descriptive statistics used to determine the prevalence and characteristics of groin injuries. The Doha agreement classification system was used to categorise all groin injuries. RESULTS: 606 footballers from 17 clubs were included, with 206/1145 (18%) time loss groin injuries sustained by 150 players, at an incidence of 1.0/1000 hours (95% CI 0.9 to 1.1). At a club level, 21% (IQR 10%-28%) of players experienced groin injuries each season and 6.6 (IQR 2.9-9.1) injuries were sustained per club per season. Of the 206 injuries, 16% were minimal (1-3 days), 25% mild (4-7 days), 41% moderate (8-28 days) and 18% severe (>28 days), with a median absence of 10 days/injury (IQR 5-22 days). The median days lost due to groin injury per club was 85 days per season (IQR 35-215 days). Adductor-related groin pain was the most common entity (68%) followed by iliopsoas (12%) and pubic-related (9%) groin pain. CONCLUSION: Groin pain caused time loss for one in five players each season. Adductor-related groin pain comprised 2/3 of all groin injuries. Improving treatment outcomes and preventing adductor-related groin pain has the potential to improve player availability in professional football.

Hip strength and range of motion: Normal values from a professional football league.

OBJECTIVES: To determine the normal profiles for hip strength and range of motion (ROM) in a professional football league in Qatar, and examine the effect of leg dominance, age, past history of injury, and ethnicity on these profiles. DESIGN: Cross-sectional cohort study. METHODS: Participants included 394 asymptomatic, male professional football players, aged 18-40 years. Strength was measured using a hand held dynamometer with an eccentric test in side-lying for hip adduction and abduction, and the squeeze test in supine with 45° hip flexion. Range of motion measures included: hip internal and external rotation in 90° flexion, hip IR in prone, bent knee fall out and hip abduction in side-lying. Demographic information was collected and the effect on the profiles was analysed using linear mixed models with repeated measures. RESULTS: Strength values (mean±SD) were: adduction=3.0±0.6Nm/kg, abduction=2.6±0.4Nm/kg, adduction/abduction ratio=1.2±0.2, Squeeze test=3.6±0.8N/kg. Range of motion values: internal rotation in flexion=32±8°, external rotation=38±8°, internal rotation in prone=38±8°, bent knee fall out=13±4.4cm, abduction in side-lying=50±7.3°. Leg dominance had no clinically relevant effect on these profiles. Multivariate analysis demonstrated that age had a minor influence on squeeze strength (-0.03N/kg/year), external rotation (-0.30°/year) and abduction range (-0.19°/year) but past history of injury, and ethnicity did not. CONCLUSIONS: Normal values are documented for hip strength and range of motion that can be used as reference profiles in the clinical assessment, screening, and management of professional football players. Leg dominance, recent past injury history and ethnicity do not need to be accounted for when using these profiles for comparison purposes.

Automatic Detection of Pitching and Throwing Events in Baseball With Inertial Measurement Sensors.

PURPOSE: Throwing loads are known to be closely related to injury risk. However, for logistic reasons, typically only pitchers have their throws counted, and then only during innings. Accordingly, all other throws made are not counted, so estimates of throws made by players may be inaccurately recorded and underreported. A potential solution to this is the use of wearable microtechnology to automatically detect, quantify, and report pitch counts in baseball. This study investigated the accuracy of detection of baseball pitching and throwing in both practice and competition using a commercially available wearable microtechnology unit. METHODS: Seventeen elite youth baseball players (mean ± SD age 16.5 ± 0.8 y, height 184.1 ± 5.5 cm, mass 78.3 ± 7.7 kg) participated in this study. Participants performed pitching, fielding, and throwing during practice and competition while wearing a microtechnology unit. Sensitivity and specificity of a pitching and throwing algorithm were determined by comparing automatic measures (ie, microtechnology unit) with direct measures (ie, manually recorded pitching counts). RESULTS: The pitching and throwing algorithm was sensitive during both practice (100%) and competition (100%). Specificity was poorer during both practice (79.8%) and competition (74.4%). CONCLUSIONS: These findings demonstrate that the microtechnology unit is sensitive to detect pitching and throwing events, but further development of the pitching algorithm is required to accurately and consistently quantify throwing loads using microtechnology.

Reduced humeral torsion predicts throwing-related injury in adolescent baseballers.

The amount of torsion in the humerus is determined by both genetic and activity-related factors, and affects the external rotation range of motion available at the shoulder. Previous research has shown athletes participating in throwing sports to have a greater amount of humeral retrotorsion in their dominant arm. The purpose of this study was to investigate the predictive ability of both the genetic and activity-related aspects of humeral torsion regarding throwing-related injury. The amount of humeral torsion in both arms of 35 high level adolescent male baseballers (mean age 16.6 years+/-0.6 years) was measured at study commencement. Significantly increased humeral retrotorsion in the dominant arm compared to the non-dominant arm was found (p=0.04). These athletes were followed for a period of 30 months, and any injury to their throwing arm which resulted in missing either a game or practice was recorded. ROC curve analysis was used to determine the predictive ability of humeral torsion with respect to the occurrence of injury to the throwing arm. Of the 35 athletes, 19 suffered a throwing arm injury. AUC values derived from ROC analysis showed humeral torsion in the non-dominant arm (AUC: 0.679, 95% CI: 0.502-0.857), as well as the average of the humeral torsion in both arms (0.692, 0.512-0.873), to be predictive of injury. Torsion in the dominant arm was not a significant throwing arm injury predictor. Thus non-dominant arm humeral torsion (the genetic contribution) was found to be the predictor of throwing arm injury.

Sports participation and humeral torsion.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To examine differences between arms in humeral torsion in adult and adolescent throwing and nonthrowing athletes, and nonathletic adults. BACKGROUND: It is hypothesized that humeral retrotorsion develops by, and is beneficial for, throwing. Thus throwers should demonstrate greater retrotorsion in their dominant arm relative to their nondominant arm and have more side-to-side retrotorsion difference than nonthrowing groups. In addition, adult throwers should have a greater side-to-side retrotorsion difference than adolescent throwers, and swimmers should not demonstrate a retrotorsion difference. METHODS AND MEASURES: Using ultrasound to standardize the location of the bicipital groove, the amount of humeral torsion was measured in both arms of male baseball players (85 adult, 35 adolescent), female softball players (16 adult, 37 adolescent), 29 elite adolescent swimmers (19 female), and 16 nonathletic adults (8 female). RESULTS: More retrotorsion was found in the dominant arm of almost all throwing athletes, irrespective of their gender or whether they were adults or adolescents (mean+/-SD side-to-side difference, 11.9 degrees+/-10.5 degrees). This difference was less for swimmers (6.4 degrees+/-9.9 degrees) and nonathletic adults (1.3 degrees+/-8.9 degrees). CONCLUSION: Greater dominant armhumeral retrotorsion is observed contingent with participation in throwing sports.