The economics of a national anterior cruciate ligament injury prevention program for amateur football players: a Markov model analysis.

OBJECTIVES: To estimate the long term cost savings, return on investment, and gain in quality-adjusted life years (QALYs) that could be achieved by a national anterior cruciate ligament (ACL) injury prevention program for amateur football (soccer) players in Australia. STUDY DESIGN: Markov model decision analysis. SETTING, PARTICIPANTS: Two hypothetical scenarios including all amateur football players in Australia (340 253 players): no intervention, and a national ACL injury prevention program. Transitions between health states, including ACL rupture, meniscal injury, knee osteoarthritis, and total knee replacement were made in one-year cycles over 35 years from a societal perspective. MAIN OUTCOME MEASURES: Cost savings, return on investment, and QALY gain achieved in the prevention program scenario relative to control scenario, by age group (10-17, 18-34, 35 years or older) and gender. SECONDARY OUTCOMES: incidence of ACL rupture, knee osteoarthritis, total knee replacement, and total knee replacement revision. RESULTS: The total mean cost of an ACL injury was estimated to be $30 665. The national injury prevention program was projected to save $52 539 751 in medical and societal costs caused by ACL ruptures in amateur footballers over 35 years; the estimated return on each dollar invested in the program was $3.51. Over this period, the number of players with ruptured ACLs could be reduced by 4385 (9%), the number of knee osteoarthritis cases by 780 (8.1%), and the number of total knee replacements by 121 (8.1%); 445 QALYs were gained. CONCLUSION: Our findings support investing in a national, evidence-based program for the primary prevention of ACL injuries in amateur football players.

Predictive modeling of lower extremity injury risk in male elite youth soccer players using least absolute shrinkage and selection operator regression.

PURPOSE: To (1) identify neuromuscular and biomechanical injury risk factors in elite youth soccer players and (2) assess the predictive ability of a machine learning approach. MATERIAL AND METHODS: Fifty-six elite male youth soccer players (age: 17.2 ± 1.1 years; height: 179 ± 8 cm; mass: 70.4 ± 9.2 kg) performed a 3D motion analysis, postural control testing, and strength testing. Non-contact lower extremities injuries were documented throughout 10 months. A least absolute shrinkage and selection operator (LASSO) regression model was used to identify the most important injury predictors. Predictive performance of the LASSO model was determined in a leave-one-out (LOO) prediction competition. RESULTS: Twenty-three non-contact injuries were registered. The LASSO model identified concentric knee extensor peak torque, hip transversal plane moment in the single-leg drop landing task and center of pressure sway in the single-leg stance test as the three most important predictors for injury in that order. The LASSO model was able to predict injury outcomes with a likelihood of 58% and an area under the ROC curve of 0.63 (sensitivity = 35%; specificity = 79%). CONCLUSION: The three most important variables for predicting the injury outcome suggest the importance of neuromuscular and biomechanical performance measures in elite youth soccer. These preliminary results may have practical implications for future directions in injury risk screening and planning, as well as for the development of customized training programs to counteract intrinsic injury risk factors. However, the poor predictive performance of the final model confirms the challenge of predicting sports injuries, and the model must therefore be evaluated in larger samples.

Biomechanical Effects of Prophylactic Knee Bracing on Anterior Cruciate Ligament Injury Risk: A Systematic Review.

OBJECTIVE: Prophylactic knee braces (PKBs) are widely used by athletes in pivoting and landing sports and have the potential to influence knee movement and alignment, thus modulating anterior cruciate ligament (ACL) injury risk. This systematic review analyses current evidence on the biomechanical effects that PKBs have in the prevention of ACL injuries. DATA SOURCES: The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Searches were conducted on PubMed, Web of Science, Scopus, Ovid MEDLINE, EMBASE, Cochrane, and CINAHL for studies published from inception until May 31, 2021. Included studies assessed the effects of PKBs on biomechanical variables associated with ACL injuries in landing or pivoting tasks, comparing between braced and unbraced conditions. MAIN RESULTS: A total of 234 articles were identified; from which, 14 controlled, laboratory, biomechanical studies were included in this review. The effects of PKBs on knee biomechanics could be divided into kinematic variables in the coronal, sagittal, and transverse planes; and common kinetic variables, such as ground reaction force (GRF) and ACL load/strain. Also, PKBs were found to have protective effects in coronal and transverse plane kinematics, but results in the sagittal plane were inconclusive. Assessing knee kinetics, PKBs were advantageous in decreasing ACL load/strain but had no significant effect on GRF. CONCLUSIONS: Prophylactic knee braces may serve to reduce ACL injury risk by modulating knee coronal and transverse plane movements and ACL load/strain during high-risk maneuvres. Precise recommendations are limited by study heterogeneity. More prospective studies are needed to assess ACL injury risk during high-risk sports using specific PKBs.

Strategies to prevent and manage running-related knee injuries: a systematic review of randomised controlled trials.

OBJECTIVE: To evaluate the effectiveness of interventions to prevent and manage knee injuries in runners. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus up to May 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials (RCTs) with a primary aim of evaluating the effectiveness of intervention(s) to prevent or manage running-related knee injury. RESULTS: Thirty RCTs (18 prevention, 12 management) analysed multiple interventions in novice and recreational running populations. Low-certainty evidence (one trial, 320 participants) indicated that running technique retraining (to land softer) reduced the risk of knee injury compared with control treadmill running (risk ratio (RR) 0.32, 95% CI 0.16 to 0.63). Very low-certainty to low-certainty evidence from 17 other prevention trials (participant range: 24 -3287) indicated that various footwear options, multicomponent exercise therapy, graduated running programmes and online and in person injury prevention education programmes did not influence knee injury risk (RR range: 0.55-1.06). In runners with patellofemoral pain, very low-certainty to low-certainty evidence indicated that running technique retraining strategies, medial-wedged foot orthoses, multicomponent exercise therapy and osteopathic manipulation can reduce knee pain in the short-term (standardised mean difference range: -4.96 to -0.90). CONCLUSION: There is low-certainty evidence that running technique retraining to land softer may reduce knee injury risk by two-thirds. Very low-certainty to low-certainty evidence suggests that running-related patellofemoral pain may be effectively managed through a variety of active (eg, running technique retraining, multicomponent exercise therapy) and passive interventions (eg, foot orthoses, osteopathic manipulation). PROSPERO REGISTRATION NUMBER: CRD42020150630.

OPTIKNEE 2022: consensus recommendations to optimise knee health after traumatic knee injury to prevent osteoarthritis.

The goal of the OPTIKNEE consensus is to improve knee and overall health, to prevent osteoarthritis (OA) after a traumatic knee injury. The consensus followed a seven-step hybrid process. Expert groups conducted 7 systematic reviews to synthesise the current evidence and inform recommendations on the burden of knee injuries; risk factors for post-traumatic knee OA; rehabilitation to prevent post-traumatic knee OA; and patient-reported outcomes, muscle function and functional performance tests to monitor people at risk of post-traumatic knee OA. Draft consensus definitions, and clinical and research recommendations were generated, iteratively refined, and discussed at 6, tri-weekly, 2-hour videoconferencing meetings. After each meeting, items were finalised before the expert group (n=36) rated the level of appropriateness for each using a 9-point Likert scale, and recorded dissenting viewpoints through an anonymous online survey. Seven definitions, and 8 clinical recommendations (who to target, what to target and when, rehabilitation approach and interventions, what outcomes to monitor and how) and 6 research recommendations (research priorities, study design considerations, what outcomes to monitor and how) were voted on. All definitions and recommendations were rated appropriate (median appropriateness scores of 7-9) except for two subcomponents of one clinical recommendation, which were rated uncertain (median appropriateness score of 4.5-5.5). Varying levels of evidence supported each recommendation. Clinicians, patients, researchers and other stakeholders may use the definitions and recommendations to advocate for, guide, develop, test and implement person-centred evidence-based rehabilitation programmes following traumatic knee injury, and facilitate data synthesis to reduce the burden of knee post-traumatic knee OA.

Editorial Commentary: Prevention of Complications During Multiple Ligament Knee Injury Reconstruction: It's Complicated!

Treatment of multiple-ligament knee injuries is complex and complicated. Surgeons should strive to keep their operative times under 5 hours, limit inside-out meniscal repair, consider fibular-based only posterolateral corner reconstructions (except in cases with associated proximal tibia-fibular joint injuries or massive posterolateral corner injuries), avoid acute surgery when possible, and proceed cautiously with ultra-low-velocity dislocations. Multiple-ligament knee injury reconstruction is challenging and complicated but a sincere thank you is extended to those surgeons who take on complex knee surgery.

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.

Increased occurrence of ACL injuries for football players in teams changing coach and for players going to a higher division.

PURPOSE: To identify football-specific factors associated with ACL injuries that can be targeted for sport-specific injury prevention. METHODS: A study-specific questionnaire was developed to study the characteristics of ACL injuries in football including intrinsic, extrinsic, and injury specific factors. The questionnaire was available at the Swedish national knee ligament registry's website for the football players to voluntarily fill out. Data are presented on group level for all football players in total and for females and males separate to examine gender-specific differences. The results are based on answers collected over a 3-year period from 2875 football players, 1762 (61%) males and 1113 (39%) females. RESULTS: ACL were more frequently sustained during games 66% than during practices 25%. The injury mechanism was non-contact in 59% and contact in 41%. For the contact injuries during games, no action was taken by the referee in 63% of the situation and a red card was shown in 0.5%. The risk of ACL injury was highest early in the football game with 47% sustained during the first 30 min and 24% in the first 15 min. Players changing to a higher level of play 15% had a higher rate of ACL injuries than players changing to a lower level 8%. This difference was especially seen in female football players with 20% of ACL injuries being sustained by players going to a higher division compared to 7% for those going to a lower division. 15% of the male and 21% of the female ACL injuries occurred in teams with a coach change during the season. Knee control exercises to warm up was used by 31% of the female players and 16% of the males. 40% of the players reported that they did not plan on returning to football. CONCLUSION: Neuromuscular training programs have proven to reduce ACL injuries, but greater adherence to these remains a challenge as only 1 in 5 of the ACL-injured football players report using them. Teams changing coach and players going to a higher division appear to have an increased risk of ACL injury warranting attention and further investigations. LEVEL OF EVIDENCE: IV.

Custom-Fitted Compression Garments Enhance Recovery From Muscle Damage in Rugby Players.

ABSTRACT: Brown, F, Jeffries, O, Gissane, C, Howatson, G, van Someren, K, Pedlar, C, Myers, T, and Hill, JA. Custom-fitted compression garments enhance recovery from muscle damage in rugby players. J Strength Cond Res 36(1): 212-219, 2022-to evaluate the effects of custom-fitted compression garments (CG) on recovery from muscle damage in rugby players. Forty-five players were tested for lower-body strength, power, and indices of muscle damage before completing a damaging protocol (20 × 20-m sprints with 5-m deceleration, 100 drop jumps). Players were randomly assigned to wear either custom-fitted (CF, n = 13), or standard-sized CG (SSG, n = 16), or to receive sham ultrasound therapy (CON, n = 16) immediately after exercise. Players were retested immediately, then after 24 and 48 hours. Strength recovery was significantly different between groups (F = 2.7, p = 0.02), with only CF recovering to baseline values by 48 hours (p = 0.973). Time × condition effects were also apparent for creatine kinase activity (χ2 = 30.4, p < 0.001) and midthigh girth (F = 3.7, p = 0.005), with faster recovery apparent in CF compared with both CON and SSG (p < 0.05). Custom-fitted CG improved strength recovery and indices of muscle damage in rugby players, compared with controls and standard-sized garments. Athletes and coaches would be advised to use appropriately fitted CG to enhance strength recovery after damaging exercise.

Reducing Knee Joint Load during a Golf Swing: The Effects of Ball Position Modification at Address.

As the modern golf swing has changed, the incidence of knee pain in professional golfers is increasing. For those with previous knee injuries, developing a golf-swing modification that reduces knee loading may be necessary to recover performance after injury. The purpose of this study was to test whether ball position modification reduces knee joint load in a golf swing. Thirteen male professional golfers participated in the study. Golf swings were captured using a three-dimensional motion capture system and two force platforms, with conditions for self-selected ball position and eight additional ball positions. Knee internal rotation and adduction moments were calculated. The length of one golf ball (4.27 cm) backward ball position (closer to the golfer) significantly reduced the peak internal rotation moment of the lead knee (- 13.8%) (p < 0.001) and the length of one golf ball (4.27 cm) away from the target ball position significantly reduced the peak adduction moment of the lead knee (- 11.5%) (p < 0.001) compared with that of the self-selected ball position. Based on these observations, we conclude that the backward ball position modification might be suggested for golfers with anterior cruciate ligament injuries, and the away from the target modification might be suggested for golfers with medial compartment knee osteoarthritis.

Injuries and illnesses among competitive Norwegian rhythmic gymnasts during preseason: a prospective cohort study of prevalence, incidence and risk factors.

OBJECTIVES: Rhythmic gymnastics is an Olympic sport that demands high training volume from early age. We investigated the extent of, and risk factors for, injuries among competitive Norwegian rhythmic gymnasts. METHODS: One hundred and seven of 133 (80.5%) female rhythmic gymnasts (mean age: 14.5 years (SD 1.6), mean body mass index: 18.9 (SD 2.2)) participated. All gymnasts completed a baseline questionnaire and the 'Triad-Specific Self-Report Questionnaire'. Injuries, illnesses and training hours were recorded prospectively for 15 weeks during preseason using the 'Oslo Sports Trauma Research Center Questionnaire on Health Problems' (OSTRC-H2). RESULTS: Response rate to OSTRC-H2 was 97%. Mean overuse and acute injury prevalence were 37% (95% CI: 36% to 39%) and 5% (95% CI: 4% to 6%), respectively. Incidence was 4.2 overuse injuries (95% CI: 3.6 to 4.9) and 1.0 acute injuries (95% CI: 0.5 to 1.6) per gymnast per year. Overuse injuries in knees, lower back and hip/groin represented the greatest burdens. Previous injury increased the odds of injury (OR 30.38, (95% CI: 5.04 to 183.25)), while increased age (OR 0.61 per year, (95% CI: 0.39 to 0.97)) and presence of menarche (OR: 0.20, (95% CI: 0.06 to 0.71)) reduced the odds of all injuries and substantial injuries, respectively. CONCLUSIONS: Overuse injuries were common among Norwegian rhythmic gymnasts. Younger gymnasts had higher all-injury risk. Gymnasts who were not menstruating had higher substantial injury risk. Injury prevention interventions should start at an early age and focus on preventing knee, lower back and hip/groin injuries.

What goes up must come down, part II: Consequences of jump strategy modification on dance leap landing biomechanics.

Knee injuries are common in jumping athletes; modifying jump strategy may impact loads placed on the body and reduce injury risk. The purpose of this study was to determine if modifying strategy in a saut de chat leap to focus on height would decrease sagittal plane knee loading. Biomechanical data were collected while 28 dancers performed saut de chat leaps with instructions to jump far (FAR) or jump high (UP). In the UP condition, there was greater vertical GRF and less braking GRF. Also in UP, lower extremity contact angle was greater (71.3 ± 2.9º FAR; 75.8 ± 3.3º UP; p = 0.0178), peak knee extensor moment was greater (2.8 ± 0.7 Nm FAR; 3.2 ± 0.8 Nm UP; p = 0.01), and peak ankle plantar flexor moment was lower (3.19 ± 0.4 Nm FAR; 2.94 ± 0.4 Nm UP; p < 0.01). A more acute LECA was related to greater braking force and braking force was related to greater knee extensor moments. Despite these relationships, we observed greater knee extensor moments in UP. While the relationship among these whole-body variables and knee joint loading exists, it may not be the primary factor driving load distribution during dance leap landings.

[Evaluation of the efficiency of therapeutic gymnastics for knee joint injuries in athletes of the senior age groups.]

The introduction and scientific substantiation of methods for organizing sports events with optimal motor loads for citizens of middle and senior age groups should be based on two principles: general (pedagogical) principles of physical education and sports training, adapted to the specifics of health-related training; analysis of physiological and psychophysiological effects that are created by physical activity of various types and directions in the human body. The importance of this topic is due to the fact that knee injuries occupy a special place in the sports of veterans, and severe injuries and injuries in this area can restrict an athlete in his professional activities. The problem of rehabilitation of athletes of older age groups with knee injuries is not only a medical problem, but also has an important socio-economic significance. The results obtained in the work will make it possible to more objectively approach the creation and implementation of rehabilitation treatment programs without surgical interventions. Therefore, the assessment of the effectiveness of the complex of medical gymnastics for the rehabilitation and prevention of traumatic injuries of the knee joint (ICD-10: S80.83, M17.23, M94.2) in comparison with the traditionally used exercise therapy exercises for patients of older age groups on the first stage of rehabilitation treatment is an urgent task.

Relationship Between 3 Single-Leg Functional Performance Tests for Netball Noncontact Knee Injury Prevention Screening in Uninjured Female Adult Players.

CONTEXT: Single- versus double-leg landing events occur the majority of the time in a netball match. Landings are involved in large proportions of netball noncontact knee injury events. Of all landing-induced anterior cruciate ligament injuries, most occur during single-leg landings. Knowledge of whether different single-leg functional performance tests capture the same or different aspects of lower-limb motor performance will therefore inform clinicians' reasoning processes and assist in netball noncontact knee injury prevention screening. OBJECTIVE: To determine the correlation between the triple hop for distance (THD), single hop for distance (SHD), and vertical hop (VH) for the right and left lower limbs in adult female netball players. DESIGN: Cross-sectional. SETTING: Local community netball club. PARTICIPANTS: A total of 23 players (age 28.7 [6.2] y; height 171.6 [7.0] cm; mass 68.2 [9.8] kg). INTERVENTIONS: There were 3 measured trials (right and left) for THD, SHD, and VH, respectively. MAIN OUTCOME MEASURES: Mean hop distance (percentage of leg length [%LL]), Pearson intertest correlation (r), and coefficient of determination (r2). RESULTS: Values (right and left; mean [SD]) were as follows: THD, 508.5 (71.8) %LL and 510.9 (56.7) %LL; SHD, 183.4 (24.6) %LL and 183.0 (21.5) %LL; and VH, 21.3 (5.2) %LL and 20.6 (5.0) %LL. All correlations were significant (P ≤ .05), r/r2 values (right and left) were THD-SHD, .91/.83 and .87/.76; THD-VH, .59/.35 and .51/.26; and SHD-VH, .50/.25 and .37/.17. A very large proportion of variance (76%-83%) was shared between the THD and SHD. A small proportion of variance was shared between the THD and VH (25%-35%) and SHD and VH (17%-25%). CONCLUSION: The THD and SHD capture highly similar aspects of lower-limb motor performance. In contrast, the VH captures aspects of lower-limb motor performance different to the THD or SHD. Either the THD or the SHD can be chosen for use within netball knee injury prevention screening protocols according to which is reasoned as most appropriate at a specific point in time. The VH, however, should be employed consistently alongside rather than in place of the THD or SHD.

Factors Associated With Lower Limb Injuries in Recreational Runners: A Cross-Sectional Survey Including Mental Aspects and Sleep Quality.

Knowledge about prevalence and etiology of running-related injuries (RRIs) is important to design effective RRI prevention programs. Mental aspects and sleep quality seem to be important potential risk factors, yet their association with RRIs needs to be elucidated. The aims of this study are to investigate the epidemiology of RRIs in recreational runners and the association of mental aspects, sleep, and other potential factors with RRIs. An internet-based questionnaire was sent to recreational runners recruited through social media, asking for personal and training characteristics, mental aspects (obsessive passion, motivation to exercise), sleep quality, perceived health, quality of life, foot arch type, and RRIs over the past six months. Data were analyzed descriptively and using logistic regression. Self-reported data from 804 questionnaires were analyzed. Twenty-five potential risk factors for RRIs were investigated. 54% of runners reported at least one RRI. The knee was the most-affected location (45%), followed by the lower leg (19%). Patellofemoral pain syndrome was the most-reported injury (20%), followed by medial tibial stress syndrome (17%). Obsessive passionate attitude (odds ratio (OR):1.35; 95% confidence interval (CI):1.18-1.54), motivation to exercise (OR:1.09; CI:1.03-1.15), and sleep quality (OR:1.23; CI:1.15-1.31) were associated with RRIs, as were perceived health (OR:0.96; CI:0.94-0.97), running over 20 km/week (OR:1.58; CI:1.04-2.42), overweight (OR:2.17; CI:1.41-3.34), pes planus (OR:1.80; CI:1.12-2.88), hard-surface running (OR:1.37; CI:1.17-1.59), running company (OR:1.65; CI:1.16-2.35), and following a training program (OR:1.51; CI:1.09-2.10). These factors together explained 30% of the variance in RRIs. A separate regression analysis showed that mental aspects and sleep quality explain 15% of the variance in RRIs. The association of mental aspects and sleep quality with RRIs adds new insights into the multifactorial etiology of RRIs. We therefore recommend that besides common risk factors for RRI, mental aspects and sleep be incorporated into the advice on prevention and management of RRIs.

Injuries in elite women's ski jumping: surveillance through the 2017-18 FIS World Cup season.

OBJECTIVES: To describe the incidence, type, aetiology and severity of injuries sustained by the International Ski Federation World Cup level female ski jumpers during the 2017-18 season. DESIGN: Prospective cohort study. METHODS: Sixty-seven female ski jump athletes from 16 countries were followed throughout the 17-week winter season. Preseason baseline demographic data and injury history were recorded via questionnaire. Prospective biweekly reports and retrospective end-of-season interviews provided data on all injuries requiring medical attention. RESULTS: Seventeen injuries were recorded, corresponding to an incidence of 25.4 injuries/100 athletes/season. The incidence of time-loss and severe injuries were found to be 17.9 and 4.5, respectively. The knee was the most common site of injury (4/17; 23.5%). Fourteen injuries occurred on the ski jump hill and crash-landing was the most common mechanism of injury (10/14; 71%). Eighty-five per cent of all moderate and severe injuries occurred in snow or windy conditions. Length of jumps resulting in injury averaged 83.7% (95% CI 72.9% to 94.4%) of hill size. Moderate injuries causing 8-28 days absence from training activities were most common (7/17; 41%) and there were three severe injuries necessitating >4 weeks absence. CONCLUSION: Injuries among elite female ski jumpers are common and the majority are acute, resulting in time loss from training and competition. The knee was the most common site of injury and poor weather conditions may be a risk factor. Future studies are needed to identify risk factors for injury and to guide injury prevention initiatives.

Functional Knee Performance Differences in Handball are Depending on Playing Class.

Handball is one of the most traumatic sports. The knee is the most commonly injured joint. To prevent knee injuries, optimal functional knee stability is of great importance. Nevertheless, there is still no consensus about objective criteria for knee function. Depending on playing class, injury rates seem to differ. The purpose of this study was to evaluate knee function in handball depending on playing class and to establish reference data for functional knee stability. 261 handball players (25.1±5.8 years) performed a functional test including two- and one-legged stability assessments, jump tests, speed and agility analysis. Except for balance, differences between playing classes were detected in all tests with superior performance of high-class players (Germany's 1st ("Oberliga") and 2nd ("Verbandsliga") non-elite playing class). High-class players achieved significant better results in jumping height (p≤0.011-0.029), relative power per body weight in the two-legged counter movement jump (p≤0.023) and speed and agility tests (p≤0.001). This study illustrates the relevance of playing class specific screening. Sports and playing class-specific databases will help to identify individual deficits and strengths in order to prevent injury and increase performance. Moreover, objective criteria for return to sports can be established.

Shoe collar height and heel counter-stiffness for shoe cushioning and joint stability in landing.

This study examined the effects of shoe collar-height and counter-stiffness on ground reaction force (GRF), ankle and knee mechanics in landing. Eighteen university basketball players performed drop landing when wearing shoes in different collar height (high vs. low) and counter-stiffness (stiffer vs. less stiff). Biomechanical variables were measured with force platform and motion capturing systems. Two-way repeated measures ANOVA was performed with α = 0.05. Wearing high collar shoes exhibited smaller peak ankle dorsiflexion and total sagittal RoM, peak knee extension moment, but larger peak knee varus moment than the low collar shoes. Stiffer counter-stiffness shoes related to smaller ankle inversion at touchdown and total coronal RoM, but larger peak knee flexion and increased total ankle and knee sagittal RoM than the less stiff counter-stiffness. Furthermore, wearing stiffer counter-stiffness shoes increased forefoot GRF peak at high collar condition, while no significant differences between counter-stiffness at low collar condition. These results suggest that although higher collar height and/or stiffness heel counter used can reduce ankle motion in coronal plane, it would increase the motion and loading at knee joint, which is susceptible to knee injuries. These findings could be insightful for training and footwear development in basketball.

Prevention of severe knee injuries in men's elite football by implementing specific training modules.

PURPOSE: Injury prevention of knee injuries by means of training and warm-up exercises has been investigated in several studies in amateur football. However, the number of investigations in elite football is limited despite the currently higher injury incidence of severe knee injuries. Therefore, the purpose of this study was to investigate whether specifically adapted preventive training modules may reduce severe knee injuries in elite football. METHODS: In a prospective controlled cohort study of elite football players in Germany, an injury prevention programme with 5 modules was implemented in the season of 2015-2016. The training modules were specifically adapted to this skill level and based on scientific evidence, team coach preferences, and the specific environment of this playing level. Of the 62 teams taking part in this study, 26 used the new trainings modules and 36 continued their standard programme as a control group. Success of the programme was documented by means of an injury report over one season. The primary outcome was reduction in severe knee injuries. RESULTS: A pre-seasonal investigation had identified five modules to be implemented in the training routine. Postural stability, mobilisation of lower extremity joints, leg and trunk stabilisation, jumping, and landing exercises as well as agility movements were incorporated into the programme to prevent severe knee injuries in elite football. Over the season, the study group (529 players) with the adapted training modules had sustained 52 severe knee injuries (incidence: 0.38 per 1000 h football exposure; prevalence: 9.8%) compared to 108 severe knee injuries in the control group (601 players) using the standard programme (incidence: 0.68 per 1000 h football exposure; prevalence: 18.0%; p < 0.05). The overall injury incidence for any other type of injury was comparable between the two groups (3.3 vs. 3.4 in h 1000 football, n.s.). CONCLUSION: Appropriate preventive training modules reduce severe knee injuries in elite football significantly. The key for the sustainability of preventive training measures are programmes specifically adapted to the demands of the playing level and to the preferences of the coaches LEVEL OF EVIDENCE: II.

Return to sports bridge program improves outcomes, decreases ipsilateral knee re-injury and contralateral knee injury rates post-ACL reconstruction.

PURPOSE: To present the results of a return to sports bridge program designed to reduce knee injuries following ACL reconstruction and physical therapy. METHODS: One hundred and fifty (male = 83, female = 67) patients participated in a whole body neuromuscular control, progressive resistance strength and agility training program. Post-program testing included functional movement form, dynamic knee stability, lower extremity power, agility, and sports skill assessments. Participants completed the Knee Outcome Survey-Sports Activity Scale (KOS-SAS) before and after program initiation. Pre-participation scores were re-estimated following program completion. RESULTS: Global rating KOS-SAS score at program entry was 75 ± 13. Post-program global rating and calculated KOS-SAS were 91.0 ± 9.8 and 90.9 ± 9.7, respectively (p < 0.0001). Pre-participation KOS-SAS score re-estimates at program completion were 54.5 ± 23.3 and 57.3 ± 18.5, respectively. The approximately 20% lower pre-program KOS-SAS score re-estimates (p < 0.0001) observed at program completion suggests that subjects had inaccurately high sports readiness perceptions at program entry. Perceived overall sports activity knee function ratings improved from 2.9 ± 0.6 (abnormal) at program entry to 1.3 ± 0.5 (normal) at completion (p < 0.0001). Most subjects returned back to sports at or above their pre-injury performance skill/performance level (84%, 126/150). By 6.8 ± 3.2 years (range = 2-13 years) post-surgery, ten subjects had sustained an ipsilateral knee re-injury or contralateral knee injury (6.7%). The 2.7% non-contact contralateral and 1.3% non-contact ipsilateral knee injury rates observed were significantly lower than those cited in previous reports. CONCLUSION: Supplementing primary ACL reconstruction and standard physical therapy with a return to sports bridge program prior to release to unrestricted sports performance was effective at improving patient outcomes and decreasing ipsilateral knee re-injury and contralateral knee injury rates. LEVEL OF EVIDENCE: II.