Role of the Menstrual Cycle on Performance and Injury Risk: A Survey of Female Professional Rugby Players in the United Kingdom.

BACKGROUND: Female athletic performance and injury risk is impacted by variations in the menstrual cycle (MC), but the understanding of the impacts and mechanisms influenced by the menstrual cycle on exercise performance are not fully delineated. AIMS AND OBJECTIVES: Evaluate associations between the menstrual cycle, perceived performance, and injury risk of elite female rugby players using an online survey. METHODS: An anonymous online questionnaire was completed by 150 elite female rugby players from two English rugby leagues, the Betfred Women's Super League (BWSL) and the Allianz Premier 15s (AP15s). The collected data were analysed thematically. RESULTS: The Chi-square test was used to assess associations between age groups and contraception usage, weight change, and training and playing performance; none of the associations were statistically significant (all p values > 0.05). Thematic analysis of 11,660 words of data revealed four themes: (a) MC impact on training and competition, (b) education and period management plans, (c) openness of conversations and comfort taking time off, and (d) injury risk. The impacted performance areas were physical (83.7%), psychological (85.7%), and nutritional (80.3%); players experienced decreased appetite, nausea, fatigue, strength declines, heighted emotions, and worsened focus. In total, 87.8% of athletes perceived the MC to negatively impact performance, 85.7% of players desired to be educated further to prevent injuries, improve nutrition, and training adaptions, 51.7% of participants perceived risk of injury to be higher during MC, and 86.4% of participants did not feel comfortable taking time off due to the MC, worrying that selection would be affected and about opinions from others. CONCLUSION: A clear negative impact on perceived performance and injury risk was reported by survey participants. The interaction of physical, psychological, and nutritional factors, and a lack of awareness and education emphasise the need for further comprehensive studies and interventions, with measures such as MC monitoring and profiling, education, and training adaptions to develop openness, knowledge, and understanding.

What exercise programme is the most appropriate to mitigate anterior cruciate ligament injury risk in football (soccer) players? A systematic review and network meta-analysis.

OBJECTIVES: To examine the effectiveness of different exercise-based interventions to mitigate the risk of anterior cruciate ligament injury in football players, and to determine which is the most appropriate for them, specifically for female football players. DESIGN: Four databases were accessed in July 2023 using the keywords football, soccer, athletic injuries, anterior cruciate ligament, knee injuries, injury prevention, exercise-based programme, and risk factor. METHODS: Randomised controlled trials that evaluated any exercise-based injury prevention intervention compared with a control group on the prevention of anterior cruciate ligament injury in football players were included. RESULTS: Eleven studies were included. Data were presented as logarithm hazard ratio, credible intervals and standard deviation. FIFA 11+ was the most effective in reducing anterior cruciate ligament injury risk in football players (logarithm hazard ratio = -1.23 [95% credible intervals: -2.20, -0.35]; SD = 0.47), followed by the Knäkontroll programme (logarithm hazard ratio = -0.76 [95% credible intervals: -1.60, -0.03]; standard deviation = 0.42). For females, only Knäkontroll had a significant impact on reducing the risk of anterior cruciate ligament injury (logarithm hazard ratio = -0.62 [95% credible intervals: -1.71, 0.62]; standard deviation = 0.58). CONCLUSIONS: Our results support the use of FIFA 11+ and Knäkontroll to mitigate injury incidence at overall level. However, the effectiveness of these interventions changed when adjusting for females. Knäkontroll is postulated as the programme with the greatest preventive nature, although these results should be interpreted with caution due to the lack of the sample.

If we build it together, will they use it? A mixed-methods study evaluating the implementation of Prep-to-Play PRO: an injury prevention programme for women's elite Australian Football.

OBJECTIVES: We evaluated the implementation of Prep-to-Play PRO, an injury prevention programme for women's elite Australian Football League (AFLW). METHODS: The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) of Prep-to-Play PRO were assessed based on the proportion of AFLW players and/or staff who: were aware of the programme (R), believed it may reduce anterior cruciate ligament injury (E), attempted to implement any/all programme components (A), implemented all intended components as practically as possible (I) and intended future programme implementation (M). Quantitative and qualitative data were triangulated to assess 58 RE-AIM items (evidence of yes/no/unsure/no evidence) and the 5 RE-AIM dimensions (fully achieved=evidence of yes on >50% dimension items, partially achieved=50% of items evidence of yes and 50% unsure or 50% mix of unsure and unanswered, or not met=evidence of yes on <50% dimension items). RESULTS: Multiple sources including AFLW training observations (n=7 total), post-implementation surveys (141 players, 25 staff), semistructured interviews (19 players, 13 staff) and internal programme records (9 staff) contributed to the RE-AIM assessment. After the 2019 season, 8 of 10 (80%) AFLW clubs fully met all five RE-AIM dimensions. All 10 clubs participating in the AFLW fully achieved the reach (R) dimension. One club partially achieved the implementation (I) dimension, and one club partially achieved the effectiveness (E) and adoption (A) dimensions. CONCLUSION: The Prep-to-Play PRO injury prevention programme for the AFLW achieved high implementation, possibly due to the programme's deliberately flexible approach coupled with our pragmatic definition of implementation. Engaging key stakeholders at multiple ecological levels (organisation, coaches, athletes) throughout programme development and implementation likely enhanced programme implementation.

Coaches of youth field sports as delivery agents of injury prevention programmes: how are we training the trainers? A scoping review.

OBJECTIVE: To systematically map the coach education (CE) component of injury prevention programmes (IPPs) for youth field sports by identifying and synthesising the design, content and facilitation strategies used to address competency drivers and behaviour change. DESIGN: Scoping review. DATA SOURCES: PubMed, PsycInfo, EMBASE, CINAHL, SportDiscus and Google Scholar electronic databases were searched using keywords related to IPPs and youth field sports. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies of IPPs in youth field sports, that provided 'train-the-trainer' education to coaches as designated delivery agents. RESULTS: 20 studies from two field sports (soccer/football; n=17, Rugby Union; n=3) fulfilled the eligibility criteria. Eleven CE interventions occurred in the preseason and 18 occurred at one time-point (single day). Five studies cited use of a behavioural change theory or model in the design of their CE, most frequently the Health Action Process Approach model (n=5); and use of behavioural change techniques varied. Twelve of twenty studies (60%) reported some form of ongoing support to coaches following the CE primary intervention concurrent with IPP implementation. CONCLUSION: CE that occurs on 1 day (one time-point) is most popular for preparing coaches as delivery agents of IPPs in youth field sports. While recognising pragmatic barriers, more expansive in-service training, support and feedback may enhance the effective implementation of IPPs. TRIAL REGISTRATION NUMBER: https://doi.org/10.17605/OSF.IO/FMHGD.

Medical imaging-based physiological characterization and performance prediction in athletes

The application of medical imaging in the physiological characterization of athletes covers multiple aspects such as injury diagnosis and monitoring, physiological structure assessment, preventive examination, and body change monitoring, which is of great significance in safeguarding athletes' health and improving their competitive performance. Field hockey is a high-intensity sport with intense confrontation, and the high incidence of knee injuries is a characteristic of athletic injuries in field hockey players. Early detection and treatment of articular cartilage injuries are of great significance to the performance of athletes' level of play and the extension of athletic injurie life. T2 mapping is a widely used cartilage MR imaging technique with high sensitivity to cartilage biochemical changes. In this paper, the T2 mapping technique was used to image the kneecap cartilage of field hockey athletes and healthy youths, to investigate the effect of field hockey on athletic injurie and the physiological characteristics of kneecap cartilage injury and to predict the development of the injury (AU)

A sports-related injury prevention program for Dutch youth volleyball players: Process evaluation alongside a quasi-randomized controlled trial.

OBJECTIVE: This process evaluation aimed to gain insight into the implementation of the VolleyVeilig Youth program by Dutch volleyball clubs within the context of an effectiveness trial. METHODS: We applied the UK Medical Research Council framework for process evaluations and assessed the context, implementation and mechanisms of impact. Trainers participating in the effectiveness trial were asked to complete a questionnaire at the end of the study. A subsample of the trainers based on the self-reported adherence score was invited to participate in an interview accordingly. We used a thematic analysis to present the data. RESULTS: Thirty-one trainers (100%) completed the questionnaire, and seven agreed to participate in an interview. Although adherence gradually decreased over the volleyball season, most trainers reported partially adhere with the program until the end of the study. The main themes included factors associated with the (1) VolleyVeilig Youth program, (2) trainer, (3) players, and (4) volleyball club. CONCLUSION: Although (partial) adherence to the VolleyVeilig Youth program was high in this study, implementation strategies must be developed to target the barriers reported by the trainers before the program can be successfully implemented nationwide in the Netherlands.

Overuse Injuries, Overtraining, and Burnout in Young Athletes.

Sports participation can have tremendous physical and mental health benefits for children. Properly implemented progressive training programs can yield a broad range of beneficial physiologic adaptations, but imbalances of training load and recovery can have important negative consequences. Overuse injuries, for example, can result from repetitive stress without sufficient recovery that leads to accumulated musculoskeletal damage. In addition, extended periods of increased training loads that exceed the intervening recovery can have systemic consequences such as overtraining syndrome, which results in decreased performance, increased injury and illness risk, and derangement of endocrine, neurologic, cardiovascular, and psychological systems. Burnout represents one of the primary reasons for attrition in youth sports. Broadly defined as physical or mental exhaustion and a reduced sense of accomplishment that leads to devaluation of sport, burnout represents a direct threat to the goal of lifelong physical activity and the wide-ranging health benefits that it provides. This clinical report is intended to provide pediatricians with information regarding the risk factors, diagnosis, management, and prevention of these conditions to assist in the identification of at-risk children, the treatment of young athletes, and the guidance of families in the promotion of safe and healthy sport participation.

Perceptions and beliefs on sports injury prediction as an injury risk reduction strategy: An online survey on elite athletics (track and field) athletes, coaches, and health professionals.

OBJECTIVES: To explore perceptions and beliefs of elite athletics (track and field) athletes, coaches, and health professionals, towards the use of injury prediction as an injury risk reduction strategy. DESIGN: Cross-sectional study. METHOD: During the 2022 European Athletics Championships in Munich, registered athletes, coaches, and health professionals were asked to complete an online questionnaire on their perceptions and beliefs of injury prediction use as an injury risk reduction strategy. The perceived level of interest, intent to use, help, potential stress (psychological impact) and dissemination were assessed by a score from 0 to 100. RESULTS: We collected 54 responses from 17 countries. Elite athletics stakeholders expressed a perceived level of interest, intent to use, and help of injury prediction of (mean ± SD) 85 ± 16, 84 ± 16, and 85 ± 15, respectively. The perceived level of potential stress was 41 ± 33 (range from 0 to 100), with an important inter-individual variability in each elite athletics stakeholder's category. CONCLUSIONS: This was the first study investigating the perceptions and beliefs of elite athletics stakeholders regarding the use of injury prediction as an injury risk reduction strategy. Regardless of the stakeholders, there was a high perceived level of interest, intent to use and help reported in this potential strategy.

We know a lot about little and little about a lot: A contextualized scoping review on injury prevention in alpine ski racing.

BACKGROUND: Our goal was to summarize and contextualize the available literature on alpine ski racing injury epidemiology, injury etiology, injury prevention measures, injury prevention context, and implementation issues. MATERIALS AND METHODS: We searched four electronic databases using predetermined search terms. We included original studies that assessed injury, injury risk factors, and injury mechanisms, and assessed and reported the effect of an injury prevention measure in alpine ski racing. Two authors independently conducted title-abstract screening, and one performed the full-text review. For data synthesis and categorization, we used the Translating Research into the Injury Prevention Practice framework and a modified and adapted version of the Haddon matrix. RESULTS: Of the 157 included studies, most corresponded to injury epidemiology and etiology, whereas few studies encompassed injury prevention measure development, implementation and evaluation. Preventive interventions targeting equipment, rules and regulations, course design and snow preparation were the most prevalent in the literature. Furthermore, various contextual factors in the current literature have been found, including gender, competition level, countries and federations, and time periods within a season. CONCLUSIONS: We provided an in-depth and comprehensive overview of the current state-of-the-art in the alpine ski racing context. We know a lot about little and little about a lot across all the areas associated with injury prevention in such context. The limitations in the literature yield a road map for designing future injury prevention studies to address the key gaps identified. A more comprehensive context-driven approach throughout all stages of injury prevention would benefit the ultimate implementation of effective preventive strategies.

'More than likely the men come first. That's just very frustrating'. A qualitative exploration of contextual factors affecting the implementation of injury prevention initiatives and the provision of effective injury management in elite-level women's club football in Ireland.

OBJECTIVES: The aim of our study was to explore the contextual factors that affect the implementation of football injury prevention initiatives and the provision of effective injury management in the Irish Women's National League (WNL). METHODS: We used a criterion-based purposive sampling approach to recruit coaches (n=7), players (n=17) and medical personnel (n=8) representing eight of the nine clubs in the WNL to participate in one-to-one semistructured interviews. Our study was located within an interpretivist, constructivist research paradigm. The interview data were analysed using reflexive thematic analysis. RESULTS: The participants identified academic and work pressures, financial challenges, conflict with college football, inadequate facilities and gender inequity as being barriers to the implementation of injury prevention initiatives and the provision of effective injury management. Financial constraints within clubs were perceived to limit the provision of medical care and strength and conditioning (S&C) support and this was deemed to be associated with a heightened risk of injuries. CONCLUSION: Specific contextual factors were identified which curtail the implementation of injury prevention initiatives and the provision of effective injury management in elite-level women's club football in Ireland. Gender inequity was identified as one of the factors impacting the availability of high-quality medical care, S&C support, as well as access to training and match facilities. Our results provide new insights that could be used to inform the design and implementation of injury prevention and management initiatives for women football players in Ireland.

Youth Injury Knowledge and Beliefs following Neuromuscular Training Warm-up Implementation in Schools.

Neuromuscular training warm-up programs can reduce injury rates in youth sports, but they often have poor uptake and adherence. Delivering such programs in school physical education classes may provide greater public health benefit, particularly if they promote improved injury knowledge and prevention beliefs amongst students. The purpose of this secondary analysis of a large cluster-randomized controlled trial was to understand how students' (age 11-15 years) knowledge and beliefs change after exposure to an evidence-informed neuromuscular training warm-up program. Six schools delivered the program for a 12-week period in the initial study year (n=566) and two continued to use it in a subsequent "maintenance" year (n=255). Students completed a knowledge and beliefs questionnaire at baseline, 6-week, and 12-week timepoints. Knowledge scores ranged from 7/10 to 8/10 at all timepoints and students generally believed that injuries are preventable. On average, there was less than a one-point change in knowledge between timepoints and there was no change in the median belief scores. There were no meaningful differences between sexes, grades, or previous injury. These findings highlight that knowledge and beliefs are unlikely to change passively through program exposure. More active strategies are needed to improve injury prevention perceptions in this population.

Tackling the tackle 2: Evaluation of referee and player behavioural change as measures of implementation of a law variation in community-level male amateur rugby union.

OBJECTIVES: To evaluate player and referee behaviour during a lower tackle height law variation trial in community rugby union ('rugby'). DESIGN: Prospective observational cohort study. METHODS: In a law variation trial in male amateur community rugby, coded match video surveillance data were analysed. Referee (sanctioning rate) and player (tackler body position) behaviour changes over one season (under the lowered, armpit-level maximum legal tackle height condition) were analysed in three approximately equal periods of the season. Secondarily, an independent professional referee reviewed illegal high tackle sanctioning data. RESULTS: Overall, 108 matches with 14,780 tackles were filmed and coded. Sanctioned illegal high tackle propensity was significantly higher in the mid-season (41 sanctioned high tackles/1000 tackle events; 95 % CI: 35-47), compared with first and last periods. Upright tacklers in tackles decreased significantly in the final vs. middle period of the season (rate ratio: 0.69; 95 % CI: 0.54-0.88; p < 0.01). Of all the coder-determined high tackles also assessed as high under the new law by the independent referee, 51 % were sanctioned by the on-field referee. CONCLUSIONS: Positive player and referee behavioural changes were observed during a lowered legal tackle height law variation in this community rugby setting. Increased mid-phase high tackle sanctioning by referees was followed by fewer tackles with upright tacklers in the subsequent (last) phase of the season. Encouraging positive behaviour changes of this nature, particularly if sustained (beyond trial study periods), may contribute to overall injury risk reduction, and hold considerable importance to inform future injury prevention strategies in rugby.

Developing the Singapore youth shoulder overuse injury prevention program.

OBJECTIVES: To develop the Singapore Youth Shoulder Overuse Injury Prevention Program specifically for competitive overhead youth athletes in Singapore. DESIGN: Two-round online Delphi technique with experts and a feasibility assessment questionnaire with youth athletes who represented end-users. SETTING: Volleyball for youth athletes. PARTICIPANTS: Experts were recruited through purposive sampling based on their knowledge and experience. Youth athletes were recruited though a volleyball club. MAIN OUTCOME MEASURES: The main outcome measure was the level of consensus on the proposed (1) exercise program for the overhead youth athletes, (2) education program regarding overuse injuries for coaches of overhead youth athletes, and (3) education program regarding overuse injuries for overhead youth athletes. Consensus was set at 75% agreement in this study. RESULTS: Eighteen experts completed the two Delphi rounds with 100% response rate. Consensus was achieved for the exercise program and both education programs. Twelve youth athletes completed the feasibility assessment questionnaire and found the exercises to be feasible in terms of usefulness, practical use, instructions, duration, and ease of execution. CONCLUSION: Consensus was reached for the Singapore Youth Shoulder Overuse Injury Prevention Program, and feasibility of execution by end-users was successfully determined.

Current concepts: the hip, core and kinetic chain in the overhead athlete.

BACKGROUND: As overhead sports continue to grow in popularity, there has been increased interest in optimizing sports performance and injury prevention in these athletes. The hip, core, and kinetic chain have become a focus of research in recent decades, and their importance in upper extremity mechanics is now being recognized. METHODS: An extensive review was carried out to identify papers correlating the hip, core and/or kinetic chain in overhead athletic performance and injury. RESULTS: Recent literature has shown that efficiency and synchrony of the hips and core during an overhead movement (such as in baseball, golf, tennis, or volleyball) is essential for a powerful and precise execution of the task. Impairments of the hip and core, particularly abnormal joint mobility or weakness, can limit efficient energy transfer through the kinetic chain and may negatively impact performance. Recent epidemiologic studies have found hip pain to be common in adolescent, collegiate, and adult athletes. Moreover, hip pain in overhead athletes specifically has also been found to occur at a high rate. Abnormalities in hip range of motion, hip morphology, and core strength can lead to abnormal mechanics upstream in the kinetic chain, which may place athletes at risk of injuries. CONCLUSION: In this review, the complex and multifaceted relationship between the hip, core, and kinetic chain is highlighted with an emphasis on recent literature and relevant findings.

Evaluation of the Value of the Y-Balance Test to Predict Lower Limb Injuries in Professional Male Footballers.

CONTEXT: The aim of this prospective cohort study was to identify whether Y-Balance Test (YBT) performance and asymmetry are associated with lower limb injury in elite adult football athletes. DESIGN: A prospective cohort study. METHODS: Preseason YBT measures were obtained from 121 male footballers participating in National League One across the 2021-2022 season. Lower limb injuries were tracked across the season to determine the relationship between YBT variables and injury incidence using logistic regression analysis. The statistical significance level was .05. RESULTS: The average YBT score was 111.0 (5.8) cm on the left limb and 112.0 (5.5) cm on the right limb, with an average asymmetry of 2.3 (1.4) cm. Athletes with lower YBT scores on both the left (odds ratio = 2.9; 95% confidence interval, 1.7 to 4.8: P ≤ .001) and right (odds ratio = 2.3; 95% confidence interval, 1.6 to 3.2: P ≤ .001) limbs were at a greater risk of injury. Similarly, athletes with greater amounts of asymmetry were also more likely to get injured (odds ratio = 2.1; 95% confidence interval, 1.3 to 3.3: P = .002). CONCLUSIONS: Results indicate that lower and asymmetrical YBT scores have a significant relationship with future lower limb injuries in professional male footballers. The YBT offers a simple, reliable, and effective screening tool that can be used by practitioners in football to help identify players at a greater risk of injury before the season commences.

Sport-related major trauma incidence in young people and adults in England and Wales: a national registry-based study.

OBJECTIVES: Data on sport and physical activity (PA) injury risk can guide intervention and prevention efforts. However, there are limited national-level data, and no estimates for England or Wales. This study sought to estimate sport and PA-related major trauma incidence in England and Wales. METHODS: Nationwide, hospital registry-based cohort study between January 2012 and December 2017. Following Trauma Audit and Research Network Registry Research Committee approval, data were extracted in April 2018 for people ≥16 years of age, admitted following sport or PA-related injury in England and Wales. The population-based Active Lives Survey was used to estimate national sport and PA participation (ie, running, cycling, fitness activities). The cumulative injury incidence rate was estimated for each activity. Injury severity was described by Injury Severity Score (ISS) >15. RESULTS: 11 702 trauma incidents occurred (mean age 41.2±16.2 years, 59.0% male), with an ISS >15 for 28.0% of cases, and 1.3% were fatal. The overall annual injury incidence rate was 5.40 injuries per 100 000 participants. The incidence rate was higher in men (6.44 per 100 000) than women (3.34 per 100 000), and for sporting activities (9.88 per 100 000) than cycling (2.81 per 100 000), fitness (0.21 per 100 000) or walking (0.03 per 100 000). The highest annual incidence rate activities were motorsports (532.31 per 100 000), equestrian (235.28 per 100 000) and gliding (190.81 per 100 000). CONCLUSION: Injury incidence was higher in motorsports, equestrian activity and gliding. Targeted prevention in high-risk activities may reduce admissions and their associated burden, facilitating safer sport and PA participation.

Shoulder Check: Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey.

OBJECTIVE: To describe shoulder-related injury rates (IRs), types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices. DESIGN: Secondary analysis of data from a 5-year prospective cohort study, Safe-to-Play (2013-2018). SETTING: Canadian youth ice hockey. PARTICIPANTS: Overall, 6584 player-seasons (representing 4417 individual players) participated. During this period, 118 shoulder-related games and 12 practice injuries were reported. ASSESSMENT OF RISK FACTORS: An exploratory multivariable mixed-effects Poisson regression model examined the risk factors of body checking policy, weight, biological sex, history of injury in the past 12 months, and level of play. MAIN OUTCOME MEASURES: Injury surveillance data were collected from 2013 to 2018. Injury rates with 95% confidence interval (CI) were estimated using Poisson regression. RESULTS: The shoulder IR was 0.35 injuries/1000 game-hours (95% CI, 0.24-0.49). Two-thirds of game injuries (n = 80, 70%) resulted in >8 days of time-loss, and more than one-third (n = 44, 39%) resulted in >28 days of time-loss. An 83% lower rate of shoulder injury was associated with policy prohibiting body checking compared with leagues allowing body checking (incidence rate ratio [IRR], 0.17; 95% CI, 0.09-0.33). A higher shoulder IR was observed for those who reported any injury in the last 12-months compared with those with no history (IRR, 2.00; 95% CI, 1.33-3.01). CONCLUSIONS: Most shoulder injuries resulted in more than 1 week of time-loss. Risk factors for shoulder injury included participation in a body-checking league and recent history of injury. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey.

Martial Arts: Orthopaedic Injuries and Related Biomechanics.

Martial arts are various systems of combat skills encompassing striking and grappling. Many styles have evolved into modern sports, and some have been included in the Olympics. The physicality of these can predispose practitioners to musculoskeletal injuries, such as anterior cruciate ligament ruptures; patellar, shoulder, or elbow instabilities; extremity fractures; and hand and spine injuries, which have been studied both clinically and biomechanically. The most common injury related to longer time loss from participation is an anterior cruciate ligament rupture. Higher injury incidence is associated with a higher level of experience and competition. Orthopaedic management of martial arts injuries should reflect the specific needs of each martial artist and the biomechanics of motions common to each style. Full-contact practitioners may benefit from broader surgical indications and special attention to the choice and positioning of implants; nonsurgical treatment may be appropriate for certain pediatric or noncontact practitioners. Approximately 60% of martial artists can return to the preinjury level of participation after a major injury. Injury prevention and rehabilitation programs should optimize neuromotor control and core engagement to ensure proper body mechanics. Gradual incorporation of martial arts movement into the postoperative physical therapy curriculum can benefit physical progress and help gain confidence toward full participation.

Reduced Match Exposure in the Previous 2 Matches Accounts for Hamstring Muscle Injury Incidence in Professional Football Players.

BACKGROUND: Hamstring strain injuries are one of the most prevalent injuries in football (soccer). We examined the influence of accumulated match-play exposure on the occurrence of hamstring strain injury in professional football from 2 teams (Spanish 1st Division, LaLiga) over 3 seasons, and determined specific cut-off points as indicators of injury risk. HYPOTHESIS: Overloaded players would be more likely to sustain a hamstring injury. STUDY DESIGN: Prospective, controlled, observational study. LEVEL OF EVIDENCE: Level 2b. METHODS: Playing time, total running distance, and high-speed running (>24 km/h) distance during official matches of players that sustained a hamstring injury were compared with uninjured, paired controls. Cumulative playing time and running performance of 4 matches before the injury was computed. Relative risk (RR) of injury occurrence was estimated by generalized estimating equations. Diagnostic accuracy was determined by receiver operating characteristics and the area under the curve. RESULTS: Thirty-seven hamstring strain injuries occurred, representing 23 ± 18 absence days per injury. Thirty-seven controls (uninjured players) were used as comparators. Low match-play exposures during 1 and 2 matches before injury were likely to explain injury occurrence (RR: 14-53%; P < 0.01). Metrics from the match before the hamstring muscle strain demonstrated the best accuracy to predict injury occurrence: high-speed running distance ≤328 m (sensitivity, 64%; specificity, 84%), playing time ≤64 min (sensitivity, 36%; specificity, 97%), and running distance ≤5.8 km (sensitivity, 39%; specificity, 97%). CONCLUSION: Relatively reduced competitive exposure in the previous 2 matches was associated with higher hamstring injury risk in professional football players. CLINICAL RELEVANCE: Screening simple metrics such as the accumulated match exposure during official matches and considering specific cut-off points for some running variables may be good indicators of injury risk and may assist in better individual injury management in professional soccer players.