Objective To systematically review and synthesise the incidence and characteristics of injuries and illnesses among athletes participating in the Olympic, Youth Olympic and Paralympic Games.Design Systematic review and meta-analysis.Data sources PubMed, Embase, CINAHL, Scopus and Web of Science were searched up to 2 July 2024, and Google Scholar, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform up to 12 December 2023.Eligibility criteria for selecting studies Cohort studies conducted during the Games reporting injuries and illnesses among athletes. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for prevalence studies, and certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation framework.Results 27 articles were included (10 Olympic, 4 Youth Olympic and 13 Paralympic Games). 23 articles had low, 3 moderate and 1 high risk of bias. Certainty of evidence was high to moderate for Olympic, high to low for Youth Olympic and low for Paralympic Games. Injury incidences per 1000 athlete-days were 6.5 (95% CI 5.9 to 7.2) during Olympic, 10.5 (95% CI 9.4 to 11.8) during Youth Olympic and 14.3 (95% CI 9.9 to 20.7) during Paralympic Games. Illness incidences per 1000 athlete-days were 3.6 (95% CI 2.8 to 4.7), 6.9 (95% CI 6.1 to 7.8) and 9.7 (95% CI 6.5 to 14.4), respectively. Lower limb injuries were frequent during Olympic and Youth Olympic Games, upper limb injuries during Paralympic Games and respiratory illnesses across all Games cohorts.Conclusions Injury and illness incidences were highest in Paralympic Games, followed by Youth Olympic and Olympic Games. Incidences and patterns of injury and illness were sport and context specific, which could inform future prevention strategies.PROSPERO registration number CRD42023475334.

Objectives: To describe physical activity patterns and analyze changes during the first two years after a non-surgically treated ACL injury, and to assess correlations between accelerometer-assessed physical activity and self-reported knee function and knee-related quality of life.Design: Prospective cohort study.Participants: 128 patients (61 females, 25.2 +/- 7.1 years) with acute ACL injuryMain outcome measures: Physical activity patterns were measured with accelerometry. Self-reported knee function was assessed using the International Knee Documentation Committee Subjective Knee Form, and knee-related quality of life was assessed using the Anterior Cruciate Ligament Quality of Life questionnaire.Results: Moderate to vigorous physical activity (MVPA) and steps per day increased from baseline to 3 months (p < .001), with no further increase from 3 to 24 months (p > .05). Time in MVPA did not correlate to patient reported outcome measures at 3, 6, 12, or 24 months (p > .05).Conclusions: Physical activity increased from acute phase to 3 months after non-surgically treated ACL injury, but almost one in four patients did not reach recommended levels of physical activity. Physical activity did not correlate with knee function or quality of life. Patients may need improved support to return to physical activity after ACL injury.

Objective To evaluate the preventive efficacy of an extended version of the Knee Control injury prevention exercise programme (IPEP) compared with an adductor strength programme and to a comparison group using a self-selected IPEP in amateur adolescent and adult male and female football players. Methods Two-armed cluster-randomised trial with an additional non-randomised arm. All 251 amateur teams (players 14-46 years) in one regional football district were approached. Teams meeting inclusion criteria were randomised to (1) extended Knee Control or (2) an adductor strength programme. Teams already using an IPEP were allocated to a comparison group and received no new intervention. Players responded to weekly questionnaires about football exposures and injuries during a 7-month season. Results Seventeen teams in the extended Knee Control, 12 in the adductor and 17 in the comparison group participated, with 502 players. For the primary outcomes, no difference in injury incidence in three lower-limb injury locations combined (hamstring, knee and ankle) was seen between extended Knee Control and the adductor group, whereas extended Knee Control had 29% lower incidence than the comparison group (incidence rate ratio 0.71, 95% CI 0.52 to 0.98). No between-group differences in groin injury incidence were seen. The weekly injury prevalence rates in the three lower limb locations combined (hamstring, knee and ankle) were 17% lower (prevalence rate ratio (PRR) 0.83, 95% CI 0.69 to 1.00) and 26% lower (PRR 0.74, 95% CI 0.63 to 0.87) in extended Knee Control compared with the adductor and comparison groups, respectively. Conclusion No difference in injury incidence was seen between the extended Knee Control and the adductor programme whereas extended Knee Control reduced injury incidence by nearly one-third compared with a self-selected IPEP. Players in extended Knee Control had lower injury prevalence compared with an adductor or self-selected IPEP.

PurposeTo describe the injury prevalence, injury pattern, and potential baseline risk factors for injuries in male and female adolescent and adult amateur football players.MethodsThis prospective study followed adolescent and adult amateur football players over one season March-October 2020. The study was completed by 462 players (130 men, age 20.0 & PLUSMN; 5.7, 14-46 years) who answered a baseline survey and a weekly web survey during the season. A total of 1456 weekly surveys were registered from males and 5041 from females. Injuries were recorded with the Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSTRC-O2). Potential baseline risk factors (age, performance of strength/conditioning training, participation in other sports, perceived importance of sporting success, self-rated training and match load, perceived balance between training/match load and recovery, previous/present injury at start of season, and injury beliefs) and their association with injury were analysed with Poisson regressions within each sex.ResultsMales reported 95 injuries (262 injury weeks, weekly prevalence 18.0% (95% CI 16.1-20.1)) and females 350 injuries (1206 injury weeks, weekly prevalence 23.9% (95% CI 22.8-25.1)). Gradual-onset injuries accounted for 57% of the injuries in males and 66% in females. For males, substantial injuries were most common in the hip/groin (weekly prevalence 3.8%), ankle (2.1%), posterior thigh (2.0%), and knee (2.0%); and for females, in the knee (4.3%), ankle (2.5%), and lower leg/Achilles tendon (2.0%). Significant risk factors for injury were higher age (rate ratio males 1.05 per year increase (95% CI 1.02-1.08), females 1.03 (95% CI 1.01-1.05)), and present injury at baseline (males 1.92 (95% CI 1.27-2.89), females 1.58 (95% CI 1.19-2.09)).ConclusionAt any given week, almost one in five male and one in four female amateur football players reported new or ongoing injuries. Hip/groin injuries were more frequent in males, while female players had a higher prevalence of knee injuries. Older players and those with an existing injury at the start of the season were more prone to new injury during the season. Rehabilitation of pre-season injury and complaints are key to reduce the injury burden in amateur football.

Objectives: To investigate risk factors for injury and illness in female and male youth floorball players (12-17 years) during a 26-week floorball season. Design: Prospective cohort study. Setting: Recreational youth sport. Participants: 471 players (142 females) 12-17 years. Main outcome measures: Weekly survey including questions about stress, sleep quality, well-being, sport exposure and average weekly rating of perceived exertion (RPE). Acute:chronic workload ratio (ACWR) was calculated. The Oslo Sports Trauma Research Center questionnaire on health problems was used. Predictors of new injury and illness were examined using multi-level logistic regression models with weekly measures nested within individuals. Results: Higher stress, poorer sleep quality and well-being increased the odds of a new injury in the subsequent week by 8% (2.0-13.5%), 10% (4.2-15.9%) and 8% (2.4-13.5%) per 1 unit increase. Higher stress, and poorer well-being increased the odds of illness by 8% (2.6-12.6%), and 12% (7.2-16.6%). ACWR below 0.8 or above 1.3 increased the odds of illness by 34% (4.9-70.8%). Conclusions: Perceived stress, well-being, and sleep quality were associated with injury and illness occurrence in the subsequent week. ACWR outside the range 0.8-1.3 was associated with illness the subsequent week. Trial registration: Clinical Trials registration NCT03309904. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

PurposeTo describe injury incidence, time trends in injury incidence, and injury characteristics among Swedish Olympic athletes over 22 years based on insurance data, as a first step to inform injury preventive measures among Olympic athletes.MethodsThe cohort comprised 762 elite athletes (54% males; age 26.5 & PLUSMN; 5.9 years) in 38 sports in the Swedish Olympic Committee support program Top and Talent between 1999 and 2020, with total 3427 athlete-years included. Acute and gradual onset injuries were reported to the insurance registry by the athletes medical staff.ResultsA total of 1635 injuries in 468 athletes were registered. The overall injury incidence was 47.7 injuries/100 athlete-years (one injury per athlete every second year). An increasing trend in injury incidence was observed in the first decade 2001 to 2010 (annual change 6.0%, 95% CI 3.3-8.8%), while in the second decade 2011 to 2020 no change was evident (0.4%, 95% CI - 1.9 to 2.7%). Gymnastics, tennis, and athletics had the highest incidence (100.0, 99.3, and 93.4 injuries/100 athlete-years, respectively). Among sport categories, mixed and power sports had the highest incidence (72.8 and 69.5 injuries/100 athlete-years, respectively). Higher incidences were seen in the younger age groups (& LE; 25 years) in mixed and skill sports. The injury incidence was comparable between male and female athletes, and summer and winter sports. Most injuries occurred in the lower limb, and specifically the knee (24%), foot/ankle (15%) and spine/pelvis (13%).ConclusionThe results on injury patterns in different sports and age groups may guide preventive focus for health and performance teams working with Olympic athletes.

Purpose To translate the ACL-QOL from English to Swedish and evaluate measurement properties for use after surgical and non-surgical management of anterior cruciate ligament (ACL) injury. Methods The ACL-QOL was translated from English to Swedish and data were pooled from 13 cohorts to enable a comprehensive evaluation of measurement properties in line with COSMIN guidelines. We evaluated internal consistency, test-re-test reliability, measurement error, structural validity [confirmatory factor analysis (CFA)], construct validity and responsiveness (hypothesis testing), and floor/ceiling effects. Results were stratified by time since injury (<= 1.5 years; 2-10 years, 15-25 years; > 30 years) and ACL management strategy [surgical (n = 1163), non-surgical (n = 570)]. Results The Swedish ACL-QOL had sufficient internal consistency (total and domain scores) for use in surgically managed (Cronbachs alpha >= 0.744) and non-surgically managed (>= 0.770) ACL-injured individuals at all time-points. Test-re-test reliability was sufficient [intraclass correlation coefficients: all domains > 0.80, total score 0.93 (95% CI 0.86-0.96)]. The standard error of measurement was 5.6 for the total score and ranged from 7.0 to 10.3 for each domain. CFA indicated sufficient SRMR values when using the total score or five domains; however, CFI and RMSEA values did not meet cut-offs for good model fit. Hypothesis testing indicated sufficient construct validity and responsiveness. Floor effects were negligible and ceiling effects were negligible or minor. Conclusion The Swedish version of the ACL-QOL has sufficient internal consistency, test-re-test reliability, construct validity and responsiveness, for use in people with ACL injury managed with or without ACL surgery. Model fit could be improved and investigation into the source of misfit is warranted.

OBJECTIVES: Analyse changes in knee laxity between 3, 6, 12 and 24 months after non-surgically treated ACL injury and to analyse associations between knee laxity and knee function, self-reported knee stability, ACL-Return to Sport after Injury (ACL-RSI), fear and confidence at different timepoints during recovery.

DESIGN: Prospective cohort study.

PARTICIPANTS: 125 patients (67 males, mean age 25.0 ± 7.0 years) with acute ACL injury.

MAIN OUTCOME: Laxity was measured using KT-1000 arthrometer. Self-reported knee function was assessed using the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Confidence and fear were assessed with questions from the ACL-RSI scale. Subjectively knee stability was assessed using SANE.

RESULTS: Knee laxity increased bilaterally from 3 to 12 months, and in the non-involved knee from 3 to 24 months (p˂0.05), although mean change was below 1 mm. Side-to-side difference in knee laxity was correlated with IKDC-SKF (r = -0.283) and knee stability in rehabilitation/sport activities (r = -0.315) at 6 months, but not with confidence/fear.

CONCLUSION: Knee laxity increased bilaterally during the first year after non-surgically treated ACL injury, though, the mean change in knee laxity was below 1 mm and the clinical significance is unknown. Knee laxity was weakly associated with knee function and perceived knee stability.

LEVEL OF EVIDENCE: Level II TRIAL REGISTRATION: NCT02931084.

Purpose Evaluate team and player compliance with the Knee Control injury prevention exercise programme, study the association between player compliance and injury rates, and compare coach demographics, baseline prevention expectancies, and programme utilisation between teams with high and low compliance. Methods Prospective one-season cohort study based on a cluster randomised controlled trial on 301 (107 female) floorball players aged 12-17 years. Floorball exposure and injuries were self-reported weekly by players using the Oslo Sports Trauma Research Center questionnaire. Team and player compliance to Knee Control was reported monthly by coaches. Additionally, coaches answered pre- and post-season surveys. Teams were divided into a high (>= 80%) or low (< 80%) compliance group based on their use of Knee Control during the season. Players were divided into three compliance groups based on their average weekly number of Knee Control sessions; high (>= 2 sessions), intermediate (>= 1 to < 2 sessions), and low dose (< 1 session). Results Mean team compliance for the high and low compliance groups were 95% (range 82-100) and 50% (range 13-66), respectively. Mean +/- SD weekly Knee Control dose in the three player compliance groups were 2.4 +/- 0.3, 1.4 +/- 0.3, and 0.7 +/- 0.3 sessions, respectively. There were no differences in total injury incidence between the player compliance groups, but players in the high-dose group had a 35% lower prevalence of injuries overall [adjusted prevalence rate ratio (PRR) 0.65, 95% CI 0.48-0.89] and 60% lower prevalence of substantial injuries (adjusted PRR 0.40, 95% CI 0.26-0.61) compared with the low-dose group. Male players in the high-dose group had consistently lower injury incidence and prevalence, while no between compliance group differences were seen in female players. There were no differences in sex, years of coaching experience, or baseline prevention expectancies in general between coaches for teams in the high vs. low compliance groups, but teams in the high compliance group had a better utilisation fidelity. Conclusion There was a clear dose-response relationship between more frequent Knee Control use and lower injury rates in male floorball players, but not in female players. Teams with higher compliance also showed a better utilisation fidelity with the programme.

Objectives: To compare neuromuscular control and hop performance between youth and adult male and female football players. Design: Cross-sectional study. Participants: 119 youth players (13-16 years; 68 males) and 88 adult players (17-26 years; 44 males). Main outcome measures: Neuromuscular control assessed with drop vertical jump (DVJ) and tuck jump assessment (TJA). Hop performance assessed with single-leg hop for distance and side hop. Results: Adult females had smaller normalized knee separation distances (NKSD) during DVJ at initial contact (77.9 +/- 18.5 vs. 86.1 +/- 11.0, p = 0.010) and at maximum knee flexion (59.7 +/- 23.4 vs.74.1 +/- 18.1, p = 0.001) compared to youth females. TJA revealed more technique errors in youths compared to adults (males 10 (8-11) vs. 8 (7-10); females 11 (9-12) vs. 9 (8-11), p < 0.05). Youths demonstrated inferior hop performance (males single-leg hop 142 +/- 18 vs. 163 +/- 17, side hop 41 +/- 12 vs. 52 +/- 12, p < 0.001; females side hop 32 +/- 10 vs. 38 +/- 14, p < 0.05). Conclusions: Youth players demonstrated reduced neuromuscular control during TJA and inferior hop performance compared to adult players. Adult female players demonstrated greater knee valgus during DVJ compared to youth female players.