'We may need some help; we are just parents who have chosen to engage in football': a qualitative study on amateur coaches' experiences of use of and support for injury prevention training in Sweden.

INTRODUCTION: Achieving sufficient adherence with injury prevention exercise programmes is a challenge. The aim was to explore how amateur football coaches experience the use of and support for injury prevention training using the Knee Control programmes as examples. METHODS: Semistructured interviews with 20 amateur football coaches around experiences of injury prevention training, facilitators and barriers, and perceived support, analysed with qualitative content analysis. Participants coached male and female, junior and senior teams. Experience of having used the Knee Control programmes was an inclusion criteria. RESULTS: Four main categories were developed: Why are we really doing this?, How do we make it work?, What are our drivers and challenges? and What could be improved? Coaches were motivated for injury prevention training but faced challenges such as limited access to football grounds and low player motivation. To make the prevention programme work for them, they integrated it and used exercises in the pauses during football-specific drills, or used as a warm-up. Many conducted prevention routines from an early player age. Coaches believed preventive training use could be further enhanced by education and practical support, and by football associations and clubs working together to reduce injuries. CONCLUSION: Coaches were motivated and creatively worked with the prevention programme to make it fit their team. Even coaches with long-term experience of using prevention programmes wanted support, indicating that present implementation strategies targeting those about to start using prevention programmes should be complemented by continuous support for maintained use. These strategies should preferably target both coaches and players.

To play or not to play, that is the question: an interview study with amateur football coaches on perceptions of pain during sports participation.

Amateur football coaches play a key role in preventing, assessing and treating pain among their players, as they are often the first point of contact and may be the main source of advice and guidance. The objective of this study was to explore amateur football coaches' perceptions of pain during sports participation and their approach to pain management. We conducted a qualitative interview study with 20 amateur football coaches from a strategically selected sample of male and female, and junior and senior teams. A semistructured interview guide and conventional qualitative content analysis were used. One overall theme emerged: To play or not to play-coaches navigating difficult terrain with limited resources. The theme included four main categories: How can pain be understood?; Can pain be avoided?; How to manage players with pain?; What resources do we need? Different ways of understanding pain emerged, and coaches described that players have different pain thresholds. Pain was seen as a part of the game that cannot be completely avoided. In general, there was a restrictive attitude regarding pain medication, though actual consumption was not known. Coaches emphasised shared responsibility with players to achieve adequate training loads, a positive communication climate surrounding pain, and a need for education and competence. In conclusion, coaches expressed various interpretations of pain during sports participation and pain management, where they need to take on great responsibility despite limited medical competence. Coaches believed that adequate pain management is important, and their keys to reducing the risk of pain included structured and customised training, a well-balanced training load and recovery, and a positive communication climate in the team. Coaches often decide whether players experiencing pain can participate in team training and match play, emphasising the need for education support and access to medical competence.

Players are positive regarding injury prevention exercise programmes, but coaches need ongoing support: a survey-based evaluation using the Health Action Process Approach model across one season in amateur and youth football.

Objectives: Implementation of injury prevention exercise programmes (IPEPs) in sports is challenging, and behaviour change among players and coaches is essential for success. The aim was to describe players' and coaches' motivation and coaches' goal pursuit when using IPEPs in amateur and youth football across a season. A secondary aim was to describe players' motivation to engage in IPEP use in relation to presence or absence of injury. Methods: The study was based on questionnaires to amateur and youth, male and female football players and coaches at baseline, mid-season and post-season in a three-armed randomised trial in 2020 in Sweden. Questionnaires were based on the Health Action Process Approach (HAPA) model with questions about the motivational phase when intention for change is created (players and coaches) and a goal-pursuit phase when intention is translated into action (coaches). Results: In total, 455 players (126 male), mean age 20.1 years (SD±5.8, range 14-46) and 59 (52 male) coaches took part. Players generally gave positive answers in the HAPA motivational phase (Likert 6-7 on a 1-7 Likert scale). Differences in ratings between injured and uninjured players were minor. Coaches had positive or neutral ratings (Likert 4-6) in the motivational and goal-pursuit phases. Ratings deteriorated across the season, with less positive responses from 40% of players and 38-46% of coaches post-season. Conclusion: Positive ratings in the HAPA motivational phase indicated fertile ground for IPEP use. Neutral ratings by coaches and deterioration across the season in players and coaches suggest a need for ongoing support for IPEP use. Trial registration number: NCT04272047.

Athletes' perspectives on return to sport after anterior cruciate ligament reconstruction and their strategies to reduce reinjury risk: a qualitative interview study.

BACKGROUND: Insights derived from athletes who have completed the final phase of rehabilitation and successfully returned to their respective sports after anterior cruciate ligament (ACL) reconstruction could potentially contribute to the enhancement of therapeutic strategies. Therefore, the aim of this study was to explore athletes' experiences, thoughts, and behaviours of final phase rehabilitation and return to sport after ACL reconstruction and to describe their thoughts about the risk of reinjury. METHODS: This qualitative interview study included individual semi-structured interviews with 15 athletes after ACL reconstruction. All athletes were aged between 15 and 35 years (median, 23 years), had returned to their preinjury contact sport at elite or recreational competitive level, rehabilitated with different physioterapists (working in hospital, primary care or sport clinics), and had undergone primary ACL reconstruction between 14 and 59 months (median, 23 months) before the interviews. Data were analysed using qualitative content analysis. RESULTS: Analysis of the data resulted in the following 4 main categories related to athletes' experiences of the return to sport process and their thoughts about the risk of reinjury: Athletes' strategies for safe return to sport; Support during rehabilitation and return to sport; The rehabilitation journey was worthwhile to be able to play again; and Reinjury is beyond one's control. CONCLUSIONS: Athletes described strategies for a safe return to sport after ACL reconstruction, emphasizing continuous increased load, not forcing return to sport, injury prevention exercises, and seeking support from professionals and coaches. Despite loving their sport, the athletes had mixed feelings about undergoing additional rehabilitation if reinjured. The athletes recognized the high reinjury risk, attributing it to fate. These findings enhance understanding of athletes' return to sport experiences after ACL reconstruction, their strategies to minimize reinjury risk, which might help optimizing care for this patient group.

Prevalence and intensity of pain in male and female amateur football players: A prospective cohort study.

OBJECTIVES: To determine the prevalence and intensity of pain due to a football-related injury during activities of daily living and during training and/or match play in both male and female and youth and adult amateur players. DESIGN: A prospective cohort study involving amateur football players. METHODS: Players (n = 502, median age 18 years, range 14-46) responded to weekly questionnaires during one season, including the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. Weekly pain prevalence and pain intensity (measured on the numeric rating scale [range 0-10]) during activities of daily living and while playing football were determined. RESULTS: A total of 6601 weekly questionnaires were collected (response rate 63.7 %). Average weekly pain prevalence during activities of daily living was 17.2 % for all players, and 15.7 % among players who participated in training and/or match play. Pain prevalence during training and/or match play was 18.3 % with an average pain intensity of 4.0. In 21.3 % of cases the recorded pain intensity was >5. Sex, age, and mode of injury onset (sudden or gradual) were not significant predictors of pain intensity. CONCLUSION: At a given week, one in six football players experiences pain during activities of daily living from a football-related injury. Almost one in five players reports pain while playing football, of whom >20% report a pain intensity above 5. Oftentimes, injury-related pain present while playing football transcends to activities of daily living. This warrants further monitoring and adequate management of pain within amateur football.

Accelerometer-assessed physical activity patterns during the first two years after a non-surgically treated ACL injury.

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 injury. MAIN 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. LEVEL OF EVIDENCE: Level II. TRIAL REGISTRATION: NCT02931084.

Higher age and present injury at the start of the season are risk factors for in-season injury in amateur male and female football players-a prospective cohort study.

PURPOSE: To describe the injury prevalence, injury pattern, and potential baseline risk factors for injuries in male and female adolescent and adult amateur football players. METHODS: This 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 ± 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. RESULTS: Males 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)). CONCLUSION: At 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. LEVEL OF EVIDENCE: Level II. Trial registration number NCT04272047, Clinical trials.

Swedish Olympic athletes report one injury insurance claim every second year: a 22-year insurance registry-based cohort study.

PURPOSE: To 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. METHODS: The cohort comprised 762 elite athletes (54% males; age 26.5 ± 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. RESULTS: A 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 (≤ 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%). CONCLUSION: The results on injury patterns in different sports and age groups may guide preventive focus for health and performance teams working with Olympic athletes. LEVEL OF EVIDENCE: II.

Implementation of the injury prevention exercise programme Knee Control+: a cross-sectional study after dissemination efforts within a football district.

BACKGROUND: The Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework can be used for evaluation of implementation initiatives in sports injury prevention. The aim was to evaluate the implementation of the injury prevention exercise programme Knee Control+ among amateur clubs and coaches in one regional football district using all five dimensions of the RE-AIM framework. METHODS: Dissemination of Knee Control+ during the 2021 season with information and webinars within one regional football district. This was followed by a cross-sectional study with questionnaires to club personnel and coaches after the season. RESULTS: The reach of Knee Control+ was fair to high, 83% of club personnel and 66% of coaches knew about the programme. 41% of club personnel and 51% of coaches had adopted it. Perceived programme effectiveness was high (6 on a 1-7 Likert scale) among coaches. Regarding implementation and maintenance, 27% of club personnel had informed coaches about Knee Control+ and 57% planned to inform coaches. The coaches had implemented the programme mainly as recommended, but half used the programme once per week or less. Intention to maintain use of the programme was high (7 on a 1-7 Likert scale) among coaches. CONCLUSION: The reach of Knee Control+ was fair to high, and adoption was fair in clubs, but there was a lack of policies for preventive training. Active strategies probably need to accompany dissemination of programme material. Reach, perceived effectiveness, adoption, implementation and planned maintenance were positive among coaches, but further studies are needed to analyse long-term maintenance.

Perceptions, facilitators, and barriers regarding use of the injury prevention exercise programme Knee Control among players and coaches in youth floorball: a cross-sectional survey study.

BACKGROUND: Youth participation in team ball sports is associated with a risk of both acute and gradual onset injuries but today there are several efficacious injury prevention exercise programmes (IPEPs). However, there is limited research about how to implement those programmes and the perceived barriers and facilitators among end-users. OBJECTIVE: To investigate perceptions of the IPEP Knee Control and facilitators and barriers to programme use among coaches and youth floorball players, and explore factors associated with planned maintenance of Knee Control. METHODS: This cross-sectional study is a sub-analysis of data from the intervention group of a cluster randomised controlled trial. Perceptions about Knee Control and facilitators and barriers to programme use were evaluated with surveys pre-intervention and post-season. 246 youth floorball players aged 12-17 years, and 35 coaches that reported no use of IPEPs during the preceding year were included. Descriptive statistics and univariate and multivariate ordinal logistic regression models were undertaken with the dependent variables: coaches' planned maintenance and players' opinions of maintenance of Knee Control. Independent variables were perceptions, facilitators and barriers regarding use of Knee Control and other potential influencing factors. RESULTS: 88% of the players believed that Knee Control can reduce injury risk. Common facilitators to Knee Control use among coaches were support, education and high player motivation, and common barriers were that injury prevention training was time-consuming, lack of space to execute the exercises and lack of player motivation. Players who planned to maintain use of Knee Control had higher outcome expectancies and belief in one's ability to use Knee Control (action self-efficacy). Coaches who planned to maintain Knee Control had higher action self-efficacy and to a lesser extent considered that Knee Control takes too much time. CONCLUSIONS: Support, education, and high player motivation are key facilitators, while lack of time and space for injury prevention training and boring exercises are key barriers for coaches and players to use Knee Control. High action self-efficacy among coaches and players seems to be a prerequisite for maintained use of IPEPs.

The Swedish version of the Anterior Cruciate Ligament Quality Of Life measure (ACL-QOL): translation and measurement properties.

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 (Cronbach's 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.

Extended Knee Control programme lowers weekly hamstring, knee and ankle injury prevalence compared with an adductor strength programme or self-selected injury prevention exercises in adolescent and adult amateur football players: a two-armed cluster-randomised trial with an additional comparison arm.

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. TRIAL REGISTRATION NUMBER: NCT04272047; Clinical trials.

Bilateral changes in knee joint laxity during the first year after non-surgically treated anterior cruciate ligament injury.

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.

Neuromuscular control and hop performance in youth and adult male and female football players.

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.

High compliance with the injury prevention exercise programme Knee Control is associated with a greater injury preventive effect in male, but not in female, youth floorball players.

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. LEVEL OF EVIDENCE: Level II.

Rehabilitation after ACL injury and reconstruction from the patients' perspective.

OBJECTIVES: To describe and compare patients' appraisal of the rehabilitation and adherence to the rehabilitation program after acute ACL injury treated with (ACLR) or without (non-ACLR) reconstruction. DESIGN: Prospective cohort study. PARTICIPANTS: 275 patients (143 females; mean age 25 ± 7 years) with acute ACL injury, of whom 166 patients had ACLR within 24 months. MAIN OUTCOME: Adherence to rehabilitation was assessed using the modified Sports Injury Rehabilitation Adherence Scale (SIRAS). RESULTS: Appraisal of rehabilitation was higher in the post-ACLR group compared to the non-ACLR group at 3 months (91% compared to 70% scored rehabilitation as necessary, p = 0.025) and at 6 months (87% compared to 70% scored it as necessary, p = 0.017). SIRAS score did not differ between 3 and 6 months for the non-ACLR group (median (IQR) 13 (2) vs 13 (2)) or the post-ACLR group (14 (1) vs 14 (2), p > 0.05). The post-ACLR group had a higher SIRAS score than the non-ACLR group at 3 and 6 months (p ≤ 0.001). CONCLUSION: Patients treated with ACLR reported valuing their rehabilitation more and rated greater adherence to the rehabilitation programme than non-surgically treated patients. As rehabilitation is essential for good knee function, strategies to improve adherence after non-ACLR treatment should be implemented. LEVEL OF EVIDENCE: Prospective cohort study, level II.

Illness prevalence and symptoms in youth floorball players: a one-season prospective cohort study involving 471 players.

OBJECTIVE: To describe weekly illness prevalence and illness symptoms by sex in youth floorball players during one season. DESIGN: Prospective cohort study. SETTING: Players who were registered to play community level floorball during the 2017-2018 season (26 weeks) in two provinces in southern Sweden. PARTICIPANTS: 471 youth players aged 12-17 years. Mean (SD) age for 329 male players 13.3 (1.0) years and 142 female players 13.7 (1.5) years. PRIMARY AND SECONDARY OUTCOME MEASURES: Weekly self-reported illness prevalence and illness symptoms according to the 2020 International Olympic Committee's consensus recommendations. RESULTS: 61% of youth floorball players reported at least one illness week during the season, with an average weekly illness prevalence of 12% (95% CI 10.8% to 12.3%). The prevalence was slightly higher among females (13%, 95% CI 11.6% to 14.3%) than males (11%, 95% CI 9.9% to 11.7%), prevalence rate ratio 1.20 (95% CI 1.05 to 1.37, p=0.009). In total, 49% (53% male, 43% female) of illness reports indicated that the player could not participate in floorball (time loss), with a mean (SD) absence of 2.0 (1.7) days per illness week. Fever (30%), sore throat (16%) and cough (14%) were the most common symptoms. Female players more often reported difficulty in breathing/tight airways and fainting, and male players more often reported coughing, feeling tired/feverish and headache. Illness prevalence was highest in the peak winter months (late January/February) reaching 15%-18% during this period. CONCLUSIONS: Our novel findings of the illness prevalence and symptoms in youth floorball may help direct prevention strategies. Athletes, coaches, parents and support personnel need to be educated about risk mitigation strategies. TRIAL REGISTRATION NUMBER: NCT03309904.

Early knee status affects self-reported knee function 1 year after non-surgically treated anterior cruciate ligament injury.

OBJECTIVES: The primary aim was to assess impact of early knee status on self-reported knee function at 3 and 12 months and on quadriceps strength at 12 months after non-surgically treated ACL injury. The secondary aim was to describe the recovery of muscle strength during the first year after the injury. DESIGN: Prospective cohort study. PARTICIPANTS: 70 patients (42 males; mean age 27 ± 7 years) with acute ACL injury. MAIN OUTCOME: Knee symptoms, knee function and sporting activities were assessed with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Muscle strength was assessed with an isokinetic dynamometer. Clinical assessment performed at baseline was used to evaluate early knee status. RESULTS: Global knee function, knee joint stability during ADL, gait pattern and one-legged squat assessed in mean 2 weeks after injury hadimpact on self-reported knee function at 3 and 12 months (r2 0.105-0.267). Mean limb symmetry index (LSI) of muscle strength and jump performance were 91-98% at 12 months. CONCLUSION: Early knee symptoms affect self-reported knee function at 3 and 12 months, while other factors are important for gaining muscle strength. Muscle strength recovered during the first year after ACL injury and reached mean LSI above 90%. LEVEL OF EVIDENCE: Prospective cohort study, level II.

Decision Making for Treatment After ACL Injury From an Orthopaedic Surgeon and Patient Perspective: Results From the NACOX Study.

BACKGROUND: In the treatment of anterior cruciate ligament (ACL) injuries, there is little evidence of when and why a decision for ACL reconstruction (ACLR) or nonoperative treatment (non-ACLR) is made. PURPOSE: To (1) describe the key characteristics of ACL injury treatment decisions and (2) compare patient-reported knee instability, function, and preinjury activity level between patients with non-ACLR and ACLR treatment decisions. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 216 patients with acute ACL injury were evaluated during the first year after injury. The treatment decision was non-ACLR in 73 patients and ACLR in 143. Reasons guiding treatment decision were obtained from medical charts and questionnaires to patients and orthopaedic surgeons. Patient-reported instability and function were obtained via questionnaires and compared between patients with non-ACLR and ACLR treatment decisions. The ACLR treatment group was classified retrospectively by decision phase: acute phase (decision made between injury day and 31 days after injury), subacute phase (decision made between 32 days and up to 5 months after injury), and late phase (decision made 5-12 months after injury). Data were evaluated using descriptive statistics, and group comparisons were made using parametric or nonparametric tests as appropriate. RESULTS: The main reasons for a non-ACLR treatment decision were no knee instability and no problems with knee function. The main reasons for an ACLR treatment decision were high activity demands and knee instability. Patients in the non-ACLR group were significantly older (P = .031) and had a lower preinjury activity level than did those in the acute-phase (P < .01) and subacute-phase (P = .006) ACLR decision groups. There were no differences in patient-reported instability and function between treatment decision groups at baseline, 4 weeks after injury, or 3 months after injury. CONCLUSION: Activity demands, not patient-reported knee instability, may be the most important factor in the decision-making process for treatment after ACL injury. We suggest a decision-making algorithm for patients with ACL injuries and no high activity demands; waiting for >3 months can help distinguish those who need surgical intervention from those who can undergo nonoperative management. REGISTRATION: NCT02931084 (ClinicalTrials.gov identifier).

Low correlation between functional performance and patient reported outcome measures in individuals with non-surgically treated ACL injury.

OBJECTIVE: Describe a consecutive cohort of people with a non-surgically treated ACL injury and evaluate correlations between functional performance and patient reported outcome measures (PROMs). DESIGN: Cross-sectional. PARTICIPANTS: Sixty-eight individuals (38 males, 18-45 years old) 2-5 years after ACL injury. MAIN OUTCOME MEASURES: Tegner Activity Scale, International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Anterior Cruciate Ligament Return to Sport after Injury scale (ACL-RSI) and ACL-Quality of Life (ACL-QoL) were completed. Functional performance was assessed using 4 hop tests and a squat test. RESULTS: Mean IKDC-SKF score was 72 ± 17 and mean LSI on performance tests were above 90%. Tegner Activity Scale was reduced from median 8 pre-injury to 5 at follow up. Satisfaction with activity level was median 7 on a 10-point ordinal scale. Correlations were moderate to strong (r = 0.552-0.856) between PROMs, negligible to weak (r = 0.003-0.403) between performance tests and PROMs and negligible to moderate (r = 0.142-0.683) between performance tests. CONCLUSION: Functional performance had negligible or weak correlation to PROMs, which indicates the need for multi-modal assessment strategies. Activity level was reduced 2-5 years after a non-surgically treated ACL injury, but most patients were able to resume physical activity at a sufficient level to maintain health and displayed symmetrical functional performance. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.