Could targeted exercise programmes prevent lower limb injury in community Australian football?

The future of in-field sports biomechanics: wearables plus modelling compute real-time in vivo tissue loading to prevent and repair musculoskeletal injuries

This paper explores the use of biomechanics in identifying the mechanistic causes of musculoskeletal tissue injury and degeneration. It appraises how biomechanics has been used to develop training programmes aiming to maintain or recover tissue health. Tissue health depends on the functional mechanical environment experienced by tissues during daily and rehabilitation activities. These environments are the result of the interactions between tissue motion, loading, biology, and morphology. Maintaining health of and/or repairing musculoskeletal tissues requires targeting the "ideal" in vivo tissue mechanics (i.e., loading and deformation), which may be enabled by appropriate real-time biofeedback. Recent research shows that biofeedback technologies may increase their quality and effectiveness by integrating a personalised neuromusculoskeletal modelling driven by real-time motion capture and medical imaging. Model personalisation is crucial in obtaining physically and physiologically valid predictions of tissue biomechanics. Model real-time execution is crucial and achieved by code optimisation and artificial intelligence methods. Furthermore, recent work has also shown that laboratory-based motion capture biomechanical measurements and modelling can be performed outside the laboratory with wearable sensors and artificial intelligence. The next stage is to combine these technologies into well-designed easy to use products to guide training to maintain or recover tissue health in the real-world.

Poor Reporting of Exercise Interventions for Hamstring Strain Injury Rehabilitation: A Scoping Review of Reporting Quality and Content in Contemporary Applied Research

OBJECTIVE

To review the quality of reporting and identify the content of exercise interventions prescribed for hamstring strain injury (HSI) rehabilitation in the scientific literature from 2010 to 2020.

DESIGN

Scoping review.

LITERATURE SEARCH

We searched the bibliometric databases Web of Science, CINAHL, SPORTDiscus, Scopus, Cochrane Library, MEDLINE, and Embase.

STUDY SELECTION CRITERIA

Original research articles (randomized controlled trials and cohort studies) published from 2010 to 2020 that described an exercise rehabilitation intervention for participants with acute HSIs were included. Injuries must have been confirmed within 7 days of occurrence via clinical assessment and/or diagnostic imaging.

DATA SYNTHESIS

The quality of reporting, in terms of completeness of exercise intervention description, was evaluated using the Consensus on Exercise Reporting Template (CERT), and the content of interventions was categorized into exercise types.

RESULTS

Fourteen studies were included; exercise intervention quality of reporting was moderate in 3 studies and low in 11 studies. Using the 19-item CERT, an average of 8.8 items (range, 4-14) were reported across all studies. Two studies reported sufficient exercise content and progression information to allow replication. Exercises categorized as hamstring flexibility, hamstring strength, running related, and non-hamstring specific were prescribed in 13, 11, 10, and 10 studies, respectively. Half of the included studies incorporated all 4 exercise types in their exercise interventions.

CONCLUSION

There is a wide variety of exercise interventions applied in published research that has addressed HSI rehabilitation. Researchers must improve reporting quality to support other professionals in replicating exercise interventions and help practitioners to effectively implement research in practice. J Orthop Sports Phys Ther 2022;52(3):130-141. Epub 21 Sep 2021. doi:10.2519/jospt.2022.10641.

A Comprehensive Summary of Systematic Reviews on Sports Injury Prevention Strategies

Background

A large volume of systematic reviews and meta-analyses has been published on the effectiveness of sports injury prevention programs.

Purpose

To provide a qualitative summary of published systematic reviews and meta-analyses that have examined the effectiveness of sports injury prevention programs on reducing musculoskeletal injuries.

Study Design

Systematic review; Level of evidence, 4.

Methods

We searched the PubMed, CINAHL, EMBASE, and the Cochrane databases for systematic reviews and meta-analyses that evaluated the effectiveness of sports injury prevention programs. We excluded published abstracts, narrative reviews, articles not published in English, commentaries, studies that described sports injury prevention strategies but did not assess their effectiveness, studies that did not assess musculoskeletal injuries, and studies that did not assess sports-related injuries. The most relevant results were extracted and summarized. Levels of evidence were determined per the Oxford Centre for Evidence-Based Medicine, and methodological quality was assessed using the AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews, revised version).

Results

A total of 507 articles were retrieved, and 129 were included. Articles pertaining to all injuries were divided into 9 topics: sports and exercise in general (n = 20), soccer (n = 13), ice hockey (n = 1), dance (n = 1), volleyball (n = 1), basketball (n = 1), tackle collision sports (n = 1), climbing (n = 1), and youth athletes (n = 4). Articles on injuries by anatomic site were divided into 11 topics: general knee (n = 8), anterior cruciate ligament (n = 34), ankle (n = 14), hamstring (n = 11), lower extremity (n = 10), foot (n = 6), groin (n = 2), shoulder (n = 1), wrist (n = 2), and elbow (n = 1). Of the 129 studies, 45.7% were ranked as evidence level 1, and 55.0% were evidence level 2. Based on the AMSTAR-2, 58.9% of the reviews reported a priori review methods, 96.1% performed a comprehensive literature search, 47.3% thoroughly described excluded articles, 79.1% assessed risk of bias for individual studies, 48.8% reported a valid method for statistical combination of data (ie, meta-analysis), 45.0% examined the effect of risk of bias on pooled study results, and 19.4% examined the risk for publication bias.

Conclusion

This comprehensive review provides sports medicine providers with a single source of the most up-to-date publications in the literature on sports injury prevention.

Controlled ecological evaluation of an implemented exercise training programme to prevent lower limb injuries in sport: differences in implementation activity

OBJECTIVE

The public health benefits of injury prevention programmes are maximised when programmes are widely adopted and adhered to. Therefore, these programmes require appropriate implementation support. This study evaluated implementation activity outcomes associated with the implementation of FootyFirst, an exercise training injury prevention programme for community Australian football, both with (FootyFirst+S) and without (FootyFirst+NS) implementation support.

METHOD

An evaluation plan based on the Reach Effectiveness Adoption Implementation Maintenance (RE-AIM) Sports Setting Matrix was applied in a controlled ecological evaluation of the implementation of FootyFirst. RE-AIM dimension-specific (range: 0-2) and total RE-AIM scores (range: 0-10) were derived by triangulating data from a number of sources (including surveys, interviews, direct observations and notes) describing FootyFirst implementation activities. The mean dimension-specific and total scores were compared for clubs in regions receiving FootyFirst+S and FootyFirst+NS, through analysis of variance.

RESULTS

The mean total RE-AIM score forclubs in the FootyFirst+S regions was 2.4 times higher than for clubs in the FootyFirst+NS region (4.73 vs 1.94; 95% CI for the difference: 1.64 to 3.74). Similarly, all dimension-specific scores were significantly higher for clubs in the FootyFirst+S regions compared with clubs in the FootyFirst+NS region. In all regions, the dimension-specific scores were highest for reach and adoption, and lowest for implementation.

CONCLUSION

Implementing exercise training injury prevention programmes in community sport is challenging. Delivering programme content supported by a context-specific and evidence-informed implementation plan leads to greater implementation activity, which is an important precursor to injury reductions.

Meta-analysis of meta-analyses of anterior cruciate ligament injury reduction training programs

Several meta-analyses have been published on the effectiveness of anterior cruciate ligament (ACL) injury prevention training programs to reduce ACL injury risk, with various degrees of risk reduction reported. The purpose of this research was to perform a systematic review and meta-analysis of overlapping meta-analyses evaluating the effectiveness of ACL injury prevention training programs so as to summarize the amount of reduction in risk for all ACL and non-contact ACL injuries into a single source, and determine if there were sex differences in the relative efficacy of ACL injury prevention training programs. Five databases (Medline, PubMed, Embase, CINAHL, and Cochrane) were searched to identify meta-analyses that evaluated the effectiveness of ACL injury prevention training programs on ACL injury risk. ACL injury data were extracted and the results from each meta-analysis were combined using a summary meta-analysis based on odds ratios (OR). Eight meta-analyses met eligibility criteria. Six of the eight only included data for female athletes. Summary meta-analysis showed an overall 50% reduction (OR = 0.5 [0.41-0.59]; I²  = 15%) in the risk of all ACL injuries in all athletes and a 67% reduction (OR = 0.33 [0.27-0.41]; I²  = 15%) for non-contact ACL injuries in females. This paper combines all previous meta-analyses into a single source and shows conclusive evidence that ACL injury prevention programs reduce the risk of all ACL injuries by half in all athletes and non-contact ACL injuries by two-thirds in female athletes. There is insufficient data to make conclusions as to the effectiveness of ACL injury prevention programs in male athletes. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2696-2708, 2018.

Controlled ecological evaluation of an implemented exercise-training programme to prevent lower limb injuries in sport: population-level trends in hospital-treated injuries

OBJECTIVE

Exercise-training programmes have reduced lower limb injuries in trials, but their population-level effectiveness has not been reported in implementation trials. This study aimed to demonstrate that routinely collected hospital data can be used to evaluate population-level programme effectiveness.

METHOD

A controlled ecological design was used to evaluate the effect of FootyFirst, an exercise-training programme, on the number of hospital-treated lower limb injuries sustained by males aged 16-50 years while participating in community-level Australian Football. FootyFirst was implemented with 'support' (FootyFirst+S) or 'without support' (FootyFirst+NS) in different geographic regions of Victoria, Australia: 22 clubs in region 1: FootyFirst+S in 2012/2013; 25 clubs in region 2: FootyFirst+NS in 2012/2013; 31 clubs region 3: control in 2012, FootyFirst+S in 2013. Interrupted time-series analysis compared injury counts across regions and against trends in the rest of Victoria.

RESULTS

After 1 year of FootyFirst+S, there was a non-statistically significant decline in the number of lower limb injuries in region 1 (2012) and region 3 (2013); this was not maintained after 2 years in region 1. Compared with before FootyFirst in 2006-2011, injury count changes at the end of 2013 were: region 1: 20.0% reduction (after 2 years support); region 2: 21.5% increase (after 2 years without support); region 3: 21.8% increase (after first year no programme, second year programme with support); rest of Victoria: 12.6% increase.

CONCLUSION

Ecological analyses using routinely collected hospital data show promise as the basis of population-level programme evaluation. The implementation and sustainability of sports injury prevention programmes at the population-level remains challenging.

Effectiveness of multicomponent lower extremity injury prevention programmes in team-sport athletes: an umbrella review

OBJECTIVE

To identify which exercise combinations are most effective as part of a lower extremity injury prevention programme for team-sport athletes.

DESIGN

Umbrella review.

DATA SOURCES

A comprehensive literature search was performed in PubMed, Scopus, Cochrane Library and PEDro databases. Studies published between January 2000 and March 2017 were included in this umbrella review.

STUDY ELIGIBILITY CRITERIA

Moderate to high-quality systematic reviews that investigated the effectiveness of a combination of two or more exercise components, that is, strength, agility, plyometrics, balance, stretching, technique, warm-up and functional activity, regarding injury incidence/rate of lower extremity injuries in team-sport athletes. The methodological quality of the included systematic reviews was independently assessed by two reviewers using the Assessing the Methodological Quality of Systematic Reviews measurement tool and the Grading of Recommendations Assessment, Development and Evaluation guidelines were used to assess the overall quality of evidence for particular outcomes.

RESULTS

Twenty-four systematic reviews met the inclusion criteria. Multicomponent exercise interventions were effective in reducing the injury incidence/rate of lower extremity, knee, ACL and ankle injuries, but not groin injuries. Strength and balance exercise components were included in 10 of 11 effective injury prevention programmes for the lower extremity, knee, ACL and ankle injuries.

SUMMARY/CONCLUSION

Lower extremity injury prevention programmes in team sports are effective in preventing lower extremity, knee, ACL and ankle injuries. Lower extremity muscle strength and balance exercises should be prioritised in lower extremity injury prevention programmes for team-sport athletes.

Working towards More Effective Implementation, Dissemination and Scale-Up of Lower-Limb Injury-Prevention Programs: Insights from Community Australian Football Coaches

Disseminating lower-limb injury-prevention exercise programs (LL-IPEPs) with strategies that effectively reach coaches across sporting environments is a way of preventing lower-limb injuries (LLIs) and ensuring safe and sustainable sport participation. The aim of this study was to explore community-Australian Football (community-AF) coaches' perspectives on the strategies they believed would enhance the dissemination and scale-up of LL-IPEPs. Using a qualitative multiple case study design, semi-structured interviews with community-AF coaches in Victoria, Australia, were conducted. Overall, coaches believed a range of strategies were important including: coach education, policy drivers, overcoming potential problem areas, a 'try before you buy approach', presenting empirical evidence and guidelines for injury-prevention exercise programs (IPEPs), forming strategic collaboration and working in partnership, communication and social marketing, public meetings, development of a coach hotline, and targeted multi-focused approaches. A shift to a culture whereby evidence-based IPEP practices in community-AF will take time, and persistent commitment by all involved in the sport is important. This will support the creation of strategies that will enhance the dissemination and scale-up of LL-IPEPs across community sport environments. The focus of research needs to continue to identify effective, holistic and multi-level interventions to support coaches in preventing LLIs. This could lead to the determination of successful strategies such as behavioural regulation strategies and emotional coping resources to implement LL-IPEPs into didactic curricula and practice. Producing changes in practice will require attention to which strategies are a priority and the most effective.

Osteoarthritis action alliance consensus opinion - best practice features of anterior cruciate ligament and lower limb injury prevention programs

AIM

To identify best practice features of an anterior cruciate ligament (ACL) and lower limb injury prevention programs (IPPs) to reduce osteoarthritis (OA).

METHODS

This consensus statement started with us performing a systematic literature search for all relevant articles from 1960 through January 2017 in PubMed, Web of Science and CINAHL. The search strategy combined the Medical Subject Heading (MeSH) and keywords for terms: (1) ACL OR “knee injury” OR “anterior cruciate ligament”; (2) “prevention and control” OR “risk reduction” OR “injury prevention” OR “neuromuscular training”; and (3) meta-analysis OR “systematic review” OR “cohort study” OR randomized. We found 166 different titles. The abstracts were reviewed for pertinent papers. The papers were reviewed by at least two authors and consensus of best practice for IPP to prevent OA was obtained by conference calls and e-mail discussions. All authors participated in the discussion.

RESULTS

The best practice features of an IPP have the following six components: (1) lower extremity and core strengthening; (2) plyometrics; (3) continual feedback to athletes regarding proper technique; (4) sufficient dosage; (5) minimal-to-no additional equipment; and (6) balance training to help prevent injuries. Exercises focused on preventing ankle sprains, hamstring injuries and lateral trunk movements are important. Plyometric exercises should focus on correcting knee valgus movement. Exercises should focus on optimizing the hamstring to quadriceps strength ratio. In order for IPP to be successful, there should be increased education and verbal feedback along with increased athletic compliance. Additional equipment is not necessary. Balance training alone does not significantly reduce injuries, but is beneficial with other exercises. Not enough evidence to recommend stretching and agility exercises, with no ill effects identified. Therefore, we suggest making these optional features.

CONCLUSION

Best practice features for ACL and lower limb IPPs to help prevent OA contain six key components along with two optional.

Deviating running kinematics and hamstring injury susceptibility in male soccer players: Cause or consequence?

BACKGROUND

Although the vast majority of hamstring injuries in male soccer are sustained during high speed running, the association between sprinting kinematics and hamstring injury vulnerability has never been investigated prospectively in a cohort at risk.

PURPOSE

This study aimed to objectify the importance of lower limb and trunk kinematics during full sprint in hamstring injury susceptibility.

STUDY DESIGN

Cohort study; level of evidence, 2.

METHODS

At the end of the 2013 soccer season, three-dimensional kinematic data of the lower limb and trunk were collected during sprinting in a cohort consisting of 30 soccer players with a recent history of hamstring injury and 30 matched controls. Subsequently, a 1.5 season follow up was conducted for (re)injury registry. Ultimately, joint and segment motion patterns were submitted to retro- and prospective statistical curve analyses for injury risk prediction.

RESULTS

Statistical analysis revealed that index injury occurrence was associated with higher levels of anterior pelvic tilting and thoracic side bending throughout the airborne (swing) phases of sprinting, whereas no kinematic differences during running were found when comparing players with a recent hamstring injury history with their matched controls.

CONCLUSION

Deficient core stability, enabling excessive pelvis and trunk motion during swing, probably increases the primary injury risk. Although sprinting encompasses a relative risk of hamstring muscle failure in every athlete, running coordination demonstrated to be essential in hamstring injury prevention.

Scientific evidence is just the starting point: A generalizable process for developing sports injury prevention interventions

BACKGROUND

The 2 most cited sports injury prevention research frameworks incorporate intervention development, yet little guidance is available in the sports science literature on how to undertake this complex process. This paper presents a generalizable process for developing implementable sports injury prevention interventions, including a case study applying the process to develop a lower limb injury prevention exercise training program (FootyFirst) for community Australian football.

METHODS

The intervention development process is underpinned by 2 complementary premises: (1) that evidence-based practice integrates the best available scientific evidence with practitioner expertise and end user values and (2) that research evidence alone is insufficient to develop implementable interventions.

RESULTS

The generalizable 6-step intervention development process involves (1) compiling research evidence, clinical experience, and knowledge of the implementation context; (2) consulting with experts; (3) engaging with end users; (4) testing the intervention; (5) using theory; and (6) obtaining feedback from early implementers. Following each step, intervention content and presentation should be revised to ensure that the final intervention includes evidence-informed content that is likely to be adopted, properly implemented, and sustained over time by the targeted intervention deliverers. For FootyFirst, this process involved establishing a multidisciplinary intervention development group, conducting 2 targeted literature reviews, undertaking an online expert consensus process, conducting focus groups with program end users, testing the program multiple times in different contexts, and obtaining feedback from early implementers of the program.

CONCLUSION

This systematic yet pragmatic and iterative intervention development process is potentially applicable to any injury prevention topic across all sports settings and levels. It will guide researchers wishing to undertake intervention development.

How do training and competition workloads relate to injury? The workload-injury aetiology model

Injury aetiology models that have evolved over the previous two decades highlight a number of factors which contribute to the causal mechanisms for athletic injuries. These models highlight the pathway to injury, including (1) internal risk factors (eg, age, neuromuscular control) which predispose athletes to injury, (2) exposure to external risk factors (eg, playing surface, equipment), and finally (3) an inciting event, wherein biomechanical breakdown and injury occurs. The most recent aetiological model proposed in 2007 was the first to detail the dynamic nature of injury risk, whereby participation may or may not result in injury, and participation itself alters injury risk through adaptation. However, although training and competition workloads are strongly associated with injury, existing aetiology models neither include them nor provide an explanation for how workloads alter injury risk. Therefore, we propose an updated injury aetiology model which includes the effects of workloads. Within this model, internal risk factors are differentiated into modifiable and non-modifiable factors, and workloads contribute to injury in three ways: (1) exposure to external risk factors and potential inciting events, (2) fatigue, or negative physiological effects, and (3) fitness, or positive physiological adaptations. Exposure is determined solely by total load, while positive and negative adaptations are controlled both by total workloads, as well as changes in load (eg, the acute:chronic workload ratio). Finally, we describe how this model explains the load-injury relationships for total workloads, acute:chronic workload ratios and the training load-injury paradox.

Self-reported worst injuries in women's Australian football identify lower limb injuries as a prevention priority

BACKGROUND

Increasing participation by women in Australian football (AF) has made understanding their specific injury prevention needs a priority. In other sports, men and women have different injury profiles. This study aims to provide the first overview of self-reported injuries in women's AF.

METHODS

Nationwide survey of women aged 17+ years who played in an AF competition was conducted following the 2014 playing season. The players' self-reported worst injury from the 2014 season is presented according to injury type, body part injured, treatment sought and games/training missed.

RESULTS

Three-quarters of 553 respondents (n=431, 78%) reported at least 1 injury. Over half (n=235, 55%) of injuries were to the lower limb. Ankle ligament tears/sprains (n=50, 12% of all injuries) and knee ligament tears/sprains (n=45, 10%) were most frequent lower limb injuries reported. Two-thirds (65%) of all lower limb injuries led to at least 1 missed game. Of 111 (26% of all injuries) upper limb injuries reported, over half (n=57, 62%) were to the hand/fingers/thumb, including fractures (n=28, 6% of all injuries), ligament tears/sprains (n=18, 4%) and dislocations (n=11, 3%). Half of the upper limb injuries (51%) resulted in players missing matches/training.

CONCLUSIONS

The most frequent self-reported worst injuries for women playing AF were joint damage to the ankle and knee. A prospective injury study is needed to confirm the causes and rate of these lower limb injuries to identify the most suitable prevention interventions.

We have the programme, what next? Planning the implementation of an injury prevention programme

Background and aim

The impact of any injury prevention programme is a function of the programme and its implementation. However, real world implementation of injury prevention programmes is challenging. Lower limb injuries (LLIs) are common in community Australian football (community-AF) and it is likely that many could be prevented by implementing exercise-based warm-up programmes for players. This paper describes a systematic, evidence-informed approach used to develop the implementation plan for a LLI prevention programme in community-AF in Victoria, Australia.

Methods

An ecological approach, using Step 5 of the Intervention Mapping health promotion programme planning protocol, was taken.

Results

An implementation advisory group was established to ensure the implementation plan and associated strategies were relevant to the local context. Coaches were identified as the primary programme adopters and implementers within an ecological system including players, other coaches, first-aid providers, and club and league administrators. Social Cognitive Theory was used to identify likely determinants of programme reach, adoption and implementation among coaches (eg, knowledge, beliefs, skills and environment). Diffusion of Innovations theory, the Implementation Drivers framework and available research evidence were used to identify potential implementation strategies including the use of multiple communication channels, programme resources, coach education and mentoring.

Conclusions

A strategic evidence-informed approach to implementing interventions will help maximise their population impact. The approach to implementation planning described in this study relied on an effective researcher-practitioner partnership and active engagement of stakeholders. The identified implementation strategies were informed by theory, evidence and an in-depth understanding of the implementation context.

Preventing Australian football injuries with a targeted neuromuscular control exercise programme: comparative injury rates from a training intervention delivered in a clustered randomised controlled trial

BACKGROUND

Exercise-based training programmes are commonly used to prevent sports injuries but programme effectiveness within community men's team sport is largely unknown.

OBJECTIVE

To present the intention-to-treat analysis of injury outcomes from a clustered randomised controlled trial in community Australian football.

METHODS

Players from 18 male, non-elite, community Australian football clubs across two states were randomly allocated to either a neuromuscular control (NMC) (intervention n=679 players) or standard-practice (control n=885 players) exercise training programme delivered as part of regular team training sessions (2× weekly for 8-week preseason and 18-week regular-season). All game-related injuries and hours of game participation were recorded. Generalised estimating equations, adjusted for clustering (club unit), were used to compute injury incidence rates (IIRs) for all injuries, lower limb injuries (LLIs) and knee injuries sustained during games. The IIRs were compared across groups with cluster-adjusted Injury Rate Ratios (IRRs).

RESULTS

Overall, 773 game injuries were recorded. The lower limb was the most frequent body region injured, accounting for 50% of injuries overall, 96 (12%) of which were knee injuries. The NMC players had a reduced LLI rate compared with control players (IRR: 0.78 (95% CI 0.56 to 1.08), p=0.14.) The knee IIR was also reduced for NMC compared with control players (IRR: 0.50 (95% CI 0.24 to 1.05), p=0.07).

CONCLUSIONS

These intention-to-treat results indicate that positive outcomes can be achieved from targeted training programmes for reducing knee and LLI injury rates in men's community sport. While not statistically significant, reducing the knee injury rate by 50% and the LLI rate by 22% is still a clinically important outcome. Further injury reductions could be achieved with improved training attendance and participation in the programme.

Specific exercise effects of preventive neuromuscular training intervention on anterior cruciate ligament injury risk reduction in young females: meta-analysis and subgroup analysis

CONTEXT

Clinical trials have demonstrated that preventive neuromuscular training (PNMT) can be effective to reduce ACL injuries in young females. However, the magnitude of the overall effect of PNMT for ACL injury reduction has not reached consensus. In addition, the effects of individual exercises in PNMT that optimise ACL injury reduction are unknown.

OBJECTIVE

The purpose of this project was to systematically review previously published clinical trials and evaluate types of exercises that best support ACL injury reduction in young females.

DATA SOURCES

The key words 'knee', 'anterior cruciate ligament', 'ACL', 'prospective', 'neuromuscular', 'training', 'female', and 'prevention' were used for studies published from 1995 to May 2012 in PubMed and EBSCO host.

STUDY SELECTION

Inclusion criteria for the current analysis were: (1) documented number of ACL injuries, (2) employed a PNMT intervention that aimed to reduce ACL injuries, (3) had a comparison group, (4) used a prospective controlled study design, (5) recruited female athletes and (6) recorded exercises implemented in the PNMT.

DATA EXTRACTION

The number of ACL injuries and female athletes in each group (control and intervention) were extracted. In addition, exercises were categorised into four types and analysed for each investigation.

DATA SYNTHESIS

A total of 14 clinical trials met the inclusion criteria. The subgroup analyses identified fewer ACL injuries in PNMT that focused on strengthening (OR 0.32, 95% CI 0.23 to 0.46, p=0.001), proximal control exercises (OR 0.33, 95% CI 0.23 to 0.47, p=0.001) and multiple exercise interventions (OR 0.32, CI 0.22 to 0.46, p=0.001).

CONCLUSIONS

The current subgroup analyses indicate strengthening, proximal control exercises and multi exercise genres increased efficacy in PNMT intervention designed to reduce ACL injury in young female athletes.

When 'just doing it' is not enough: assessing the fidelity of player performance of an injury prevention exercise program

OBJECTIVES

To obtain benefits from sports injury prevention programs, players are instructed to perform the exercises as prescribed. We developed an observational checklist to measure the quality of exercise performance by players participating in FootyFirst, a coach-led, exercise-based, lower-limb injury prevention program in community Australian Football (AF).

DESIGN

Observational.

METHODS

The essential performance criteria for each FootyFirst exercise were described in terms of the technique, volume and intensity required to perform each exercise. An observational checklist was developed to evaluate each criterion through direct visual observation of players at training. The checklist was trialled by two independent raters who observed the same 70 players completing the exercises at eight clubs. Agreement between observers was assessed by Kappa-statistics. Exercise fidelity was defined as the proportion of observed players who performed all aspects of their exercises correctly.

RESULTS

The raters agreed on 61/70 observations (87%) (Kappa=0.72, 95% CI: 0.55; 0.89). Of the observations with agreed ratings, 41 (67%) players were judged as performing the exercises as prescribed.

CONCLUSIONS

The observational checklist demonstrated high inter-rater reliability. Many players observed did not perform the exercises as prescribed, raising concern as to whether they would be receiving anticipated program benefits. Where quality of exercise performance is important, evaluation and reporting of program fidelity should include direct observations of participants.

Changes in muscle activation following balance and technique training and a season of Australian football

OBJECTIVES

Determine if balance and technique training implemented adjunct to 1001 male Australian football players' training influenced the activation/strength of the muscles crossing the knee during pre-planned and unplanned sidestepping.

DESIGN

Randomized Control Trial.

METHODS

Each Australian football player participated in either 28 weeks of balance and technique training or 'sham' training. Twenty-eight Australian football players (balance and technique training, n=12; 'sham' training, n=16) completed biomechanical testing pre-to-post training. Peak knee moments and directed co-contraction ratios in three degrees of freedom, as well as total muscle activation were calculated during pre-planned and unplanned sidestepping.

RESULTS

No significant differences in muscle activation/strength were observed between the 'sham' training and balance and technique training groups. Following a season of Australian football, knee extensor (p=0.023) and semimembranosus (p=0.006) muscle activation increased during both pre-planned sidestepping and unplanned sidestepping. Following a season of Australian football, total muscle activation was 30% lower and peak valgus knee moments 80% greater (p=0.022) during unplanned sidestepping when compared with pre-planned sidestepping.

CONCLUSIONS

When implemented in a community level training environment, balance and technique training was not effective in changing the activation of the muscles crossing the knee during sidestepping. Following a season of Australian football, players are better able to support both frontal and sagittal plane knee moments. When compared to pre-planned sidestepping, Australian football players may be at increased risk of anterior cruciate ligament injury during unplanned sidestepping in the latter half of an Australian football season.

What do community football players think about different exercise-training programmes? Implications for the delivery of lower limb injury prevention programmes

BACKGROUND

Players are the targeted end-users and beneficiaries of exercise-training programmes implemented during coach-led training sessions, and the success of programmes depends upon their active participation. Two variants of an exercise-training programme were incorporated into the regular training schedules of 40 community Australian Football teams, over two seasons. One variant replicated common training practices, while the second was an evidence-based programme to alter biomechanical and neuromuscular factors related to risk of knee injuries. This paper describes the structure of the implemented programmes and compares players' end-of-season views about the programme variants.

METHODS

This study was nested within a larger group-clustered randomised controlled trial of the effectiveness of two exercise-training programmes (control and neuromuscular control (NMC)) for preventing knee injuries. A post-season self-report survey, derived from Health Belief Model constructs, included questions to obtain players' views about the benefits and physical challenges of the programme in which they participated.

RESULTS

Compared with control players, those who participated in the NMC programme found it to be less physically challenging but more enjoyable and potentially of more benefit. Suggestions from players about potential improvements to the training programme and its future implementation included reducing duration, increasing range of drills/exercises and promoting its injury prevention and other benefits to players.

CONCLUSIONS

Players provide valuable feedback about the content and focus of implemented exercise-training programmes, that will directly inform the delivery of similar, or more successful, programmes in the future.