ACL injury prevention: Where have we come from and where are we going?

Coaching the coaches: exploring the effectiveness of the 'Move Well Be strong' youth injury prevention programme for grassroot coaches and PE teachers

INTRODUCTION

Coaches play a major role in developing movement in their performers, especially at grassroots levels. However, there are significant knowledge gaps amongst grassroots coaches and physical education (PE) teachers regarding movement competency and injury prevention programs. This study aimed to explore the effectiveness of knowledge gain, adoption and implementation following a youth injury prevention workshop for grassroots coaches and PE teachers.

METHODS

56 grassroots coaches and PE teachers completed a validated questionnaire exploring use, knowledge, attitude towards and confidence to deliver youth movement competency training before and after an online workshop. Bayesian Wilcoxon signed-rank tests were used to assess the knowledge, attitude, and confidence to deliver an injury prevention programme following the workshop. For all the Bayesian inference tests run, the Bayesian factor (BF10) was interpreted using the evidence categories ranging from extreme evidence (BF10 > 100) to anecdotical evidence (BF10 < 1).

RESULTS

Post-workshop there was a 34% increase in respondents indicating that they had greater knowledge of injury prevention issues (55% pre-workshop vs 89% post-workshop) with statistically positive and moderate effects (BF10 > 100 [extreme evidence]). There was also a 25% increase in respondents indicating that they had a more sympathetic attitude towards injury prevention (67% sympathetic pre-workshop vs 93% sympathetic post-workshop) with statistically moderate effects (BF10 = 87.4 [very strong evidence]). A 19% increase in attendees' confidence to deliver an injury prevention programme was observed (69% high pre-workshop vs. 89% high post-workshop) with statistically moderate effects (BF10 = 85.9 [very strong evidence]). 100% of participants indicated an intent to adopt the injury prevention programme.

CONCLUSIONS

An online workshop increased knowledge and confidence in grassroots coaches and PE teachers to deliver a youth injury prevention programme. Knowledge gained from training and upskilling created a positive attitude and confidence to deliver movement competency into coaching. Appropriate resources need to be developed and delivered in an accessible way to grassroots coaches and PE teachers via workshops and should be included in governing body coaching awards or as continuing professional development for youth coaches and PE teachers.

Comparison of two implementation strategies for anterior cruciate ligament injury prevention in amateur girls' youth soccer: a prospective cohort study

Objectives

To compare two implementation strategies, an educational handout and a knowledge-to-action (KTA) intervention, for promoting anterior cruciate ligament (ACL) injury prevention programme (ACL-IPP) implementation in amateur youth girls' soccer. The primary outcomes assessed include frequency of ACL-IPP implementation and ACL injury risk.

Methods

This was a prospective cohort study, which followed 671 amateur female soccer players (15.72±1.78 years) whose coaches received either a KTA intervention (n=400) or an educational handout (n=271) regarding implementing an ACL-IPP. Over a single season, we tracked the number of ACL injuries weekly and implementation rates at the end of the season through surveying participating coaches. A χ2 test was used to compare the ACL-IPP implementation rate between the handout and KTA intervention. Cox-hazard proportional regressions were used to examine the effect of implementation rate and educational interventions on ACL injuries.

Results

The KTA intervention yielded higher ACL-IPP implementation as compared with the educational handout (X2 (1, n=671)=25.87, p<0.001). Implementation of any ACL-IPP at least two times per week was associated with a lower risk of ACL injuries (HR=0.15, 95% CI=0.03, 0.73; p=0.019) compared with implementing once per week or fewer. The KTA intervention was not associated with a significantly lower risk of ACL injuries (HR=0.39, 95% CI=0.09, 1.61; p=0.191) compared with the educational handout.

Conclusion

Stakeholder engagement in the process of planning and execution of IPPs, such as with a KTA intervention, appears beneficial for the purposes of increasing implementation rates. Since implementation was significantly associated with lower rates of ACL injuries, this process may lead to improved results in injury prevention in amateur youth soccer.

Differential influence of quadriceps rate of torque development on single- and double-leg landing mechanics in anterior cruciate ligament reconstructed and control females

PURPOSE

The capacity to explosively contract quadriceps within the critical timeframe associated with anterior cruciate ligament (ACL) injury, quantified by the rate of torque development, is potentially essential for safe landing mechanics. This study aimed to investigate the influence of explosive quadriceps strength on ACL-related sagittal-plane landing mechanics in females with and without ACL reconstruction (ACLR).

METHODS

Quadriceps explosive strength and landing mechanics were assessed in 19 ACLR and 19 control females during isometric contractions and double- and single-leg jump landings. A stepwise multiple linear regression model determined the variance in each of the landing biomechanics variables for the ACLR limb and nondominant limb of controls that could be explained by the group, rate of torque development and/or their interaction. If peak kinetic variables could be predicted by the rate of torque development or interaction, additional analyses were conducted, accounting for knee flexion as a covariate in the regression model.

RESULTS

During single-leg landings, ACLR females exhibited greater knee flexion at initial contact than controls (p = 0.04). Greater quadriceps rate of torque development predicted higher peak posterior ground reaction force and anterior tibial shear force in both groups (p = 0.04). However, after controlling for knee flexion angle at those peak forces, quadriceps rate of torque development was not predictive. In double-leg landings, greater explosive quadriceps strength was associated with quicker attainment of peak knee extension moment and posterior ground reaction force in the ACLR limb (p = 0.03).

CONCLUSION

Regardless of ACL injury status, females with greater explosive quadriceps strength adopted safer single-leg landings through increased knee flexion, potentially mitigating ACL loading despite encountering higher peak forces. During double-leg landings, a greater explosive quadriceps strength of the ACLR limb is associated with faster achievement of peak force upon landing. Incorporating explosive quadriceps strengthening into post-ACLR rehabilitation and injury prevention programmes may enhance landing mechanics for reducing primary and subsequent ACL injury risks.

LEVEL OF EVIDENCE

Level II.

Perspectives on reasons why football and handball players sustain acute and severe knee injuries: a mixed-methods concept mapping study

ABSTRACT

Background

The high incidence of knee injuries in football/handball challenges effective prevention. Identifying tangible and modifiable factors associated with a knee injury may innovate preventive actions. Engaging key stakeholders can reveal crucial insights that could improve knee injury prevention in football/handball.

Objective

To investigate football/handball stakeholders' perspectives on reasons for acute and severe knee injuries to generate a conceptual model on important factors associated with knee injuries in football/handball.

Methods

Mixed-method participatory Group Concept Mapping was applied to collect statements from football/handball stakeholders (players/coaches/healthcare staff/researchers) on the question, 'What may explain why some players sustain a knee injury?'. Participants rated the importance and feasibility of screening for each statement. Multidimensional scaling and hierarchical cluster analysis produced a cluster map, forming the basis for developing a final conceptual model.

Results

Stakeholders (n=37) generated and sorted 100 statements. Cluster analysis followed by cluster map validation yielded seven themes: (1) the player's physical and motor skill profile, (2) preparation and training, (3) footwear and playing surface, (4) the sport's impact on the risk of injury, (5) mental and physical fatigue, (6) history of injury and 7) genetics and context. A final conceptual model illustrating factors associated with knee injuries in football/handball was developed. Forty-six statements were identified as both important and feasible to screen for.

Conclusions

Stakeholders' perspectives on knee injuries in football/handball revealed a complex interplay of factors. We developed a conceptual model fostering stakeholder dialogue for enhanced prevention. Key among its themes is 'preparation and training'.

Single-legged landing behavior of high school basketball players with chronic ankle instability

OBJECTIVES

Anterior cruciate ligament injury is one of the most serious ligamentous injuries. The purpose is to compare the impact of the ankle joint on the knee during landing between athletes with chronic instability and a control group (coper group) and to verify the effects of the kinetic chain from other joints.

DESIGN

Prospective study.

SETTING

High school basketball.

PARTICIPANTS

Participants were 62 female high school basketball players who had participated in team sports for >6 months.

MAIN OUTCOME MEASURES

Player joint angles, movements, and moments.

RESULTS

The knee valgus moment was significantly higher in the chronic ankle instability group than in the coper group (20%-60% [p < 0.01]; 80%-100% [p < 0.05]) during landing motion. The knee valgus moment was also significantly higher during the change from the maximum knee joint flexion position to the maximum extension (p < 0.05). In addition, the landing motions of the chronic instability group may have utilized suboptimal compensatory motor strategy on the sagittal plane, depending heavily on the knee joint's abduction moment.

CONCLUSIONS

Our findings indicate that the chronic ankle instability group uses a different landing strategy pattern than the coper group by changing the joint moment and joint angle during landing, which may increase the risk of anterior cruciate ligament injury.

Factors Associated With Awareness, Adoption, and Implementation of Anterior Cruciate Ligament Injury Prevention in Youth Sports

BACKGROUND

Anterior cruciate ligament (ACL) injuries are among the most common injuries in adolescent athletes and result in significant financial and physical morbidity. Evidence-based programs designed to prevent ACL injury are effective. However, their adoption remains low. We sought to evaluate the awareness, evidence-based implementation, and barriers to implementation of ACL injury prevention programs (ACL-IPP) among youth athletic coaches.

HYPOTHESIS

Higher education level of the coach, higher level of training, number of teams coached, and coaching female teams would be associated with ACL-IPP implementation.

STUDY DESIGN

Cross-sectional survey.

LEVEL OF EVIDENCE

Level 4.

METHODS

We conducted an email survey sent to all 63 school districts within Section VI of the New York State Public High School Athletic Association. We employed descriptive statistics and tests of correlation to identify factors associated with ACL-IPP implementation.

RESULTS

A total of 73% of coaches said they were aware of ACL-IPP, and only 12% of coaches implemented ACL-IPP according to best evidence. Coaches of higher competitive levels were more likely to adopt ACL-IPP (P = 0.01), more likely to use them multiple times per week (P = 0.03), and for ≥1 seasons (P = 0.02). Coaches of multiple teams were more likely to adopt ACL-IPP (P = 0.01). There were no differences in evidence-based implementation of ACL-IPP with gender coached or level of education of the coach.

CONCLUSION

Overall awareness, adoption, and evidence-based implementation of ACL-IPP remain low. These results suggest that coaches at higher levels of play and multiple teams tend to use ACL-IPP more often. Gender coached and level of education do not appear to be associated with awareness or implementation.

CLINICAL RELEVANCE

Evidence-based ACL-IPP implementation remains low. Targeting coaches of younger athletes and fewer teams with local outreach programs and ACL-IPP may increase the implementation of ACL-IPP.

Polymorphism of Genes Encoding Inflammatory Interleukins and the Risk of Anterior Cruciate Ligament Injury: A Systematic Review and Meta-Analysis

Sport injuries, including the anterior crucial ligament rupture (ACLR) seem to be related to complex genetic backgrounds, including the genes responsible for inflammatory response. This review and meta-analysis investigated the contribution of the polymorphisms of genes encoding inflammatory cytokines and their receptors to the risk of ACLR. The scientific databases Science Direct, EBSCO host, Scopus, PubMed, and Google Scholar were screened (completed on 14 June 2023) according to the established inclusion/exclusion criteria (only fully accessible, original, human case-control studies written in English concerning the effect of interleukin genes' polymorphisms on the occurrence of ACL injury were included) and statistical meta-analysis using R version 4.0.3 was performed. The PRISMA methodology was used to review articles. The review protocol was registered under the number CRD42024514316 in the Prospero database. Eighty-nine studies were identified and narrowed down to three original case-control studies used for the meta-analysis. The studies analyzed Polish, South African, and Swedish cohorts, altogether 1282 participants. The candidate polymorphisms indicated in the studies involved IL6 rs1800795, IL6R rs2228145 and IL1B rs16944. The systematic review showed the relationships between IL6 rs1800795 polymorphism and ACLR in the Polish subpopulation, and IL6R rs2228145 and IL1B rs16944 in the South African subpopulations. The meta-analysis revealed that the IL6 rs1800795 CG genotype was over-represented (OR = 1.30, 95% CI 1.02-1.66), while the CC genotype was under-represented (OR = 0.75, 95% CI 0.54-1.03) in ACLR subjects, but no significant impact of IL6R rs2228145 was shown. Additionally, a tendency of the IL1B rs16944 CT genotype to be protective (OR 0.89, 95% CI 0.70-1.14), while the TT to be a risk genotype (OR 1.19, 95% CI 0.84-1.68) was observed. Thus, the relationship between the interleukin receptor IL6R rs2228145 and ACLR risk was not confirmed. However, the impact of genes coding pleiotropic IL6 rs1800795 on the incidences of ACLR was clear and the effect of pro-inflammatory IL1B rs16944 was possible.

Decreased sagittal slope of the medial tibial spine and deep concavity of the lateral tibial spine are risk factors for noncontact anterior cruciate ligament injury

PURPOSE

This study aimed to assess the relationship between the geometric features of tibial eminence and susceptibility to noncontact anterior cruciate ligament (ACL) injuries.

METHODS

Patients with unilateral noncontact knee injuries between 2015 and 2021 were consecutively enroled in this study. Based on knee magnetic resonance imaging (MRI) and arthroscopic visualisation, patients were categorised into the case group (ACL rupture) and control group (ACL intact). Using MRI, the geometric features of tibial eminence were characterised by measuring the sagittal slopes, depth of concavity and coronal slopes of the inclined surfaces of the tibial spines. Univariate and multivariate logistic regressions were conducted to explore independent associations between quantified geometric indices of tibial eminence and the risk of noncontact ACL injuries.

RESULTS

This study included 187 cases and 199 controls. A decreased sagittal slope of the medial tibial spine (MTSSS) (combined group: odds ratio [OR]: 0.87 [0.82, 0.92], p < 0.001; females: OR: 0.88 [0.80, 0.98], p = 0.020; males: OR: 0.87 [0.81, 0.93], p < 0.001) and an increased depth of concavity in the lateral tibial spine (LTSD) (combined group: OR: 1.51 [1.24, 1.85], p < 0.001; females: OR: 1.65 [1.12, 2.43], p = 0.012; males: OR: 1.44 [1.11, 1.89], p = 0.007) were independent risk factors for noncontact ACL injuries. Moreover, a steeper coronal slope of the inclined surface of the medial tibial spine was a significant predictor of noncontact ACL injuries for males (MTSCS: OR: 1.04 [1.01, 1.08], p = 0.015) but not for females.

CONCLUSION

Geometric features of tibial eminence, particularly a decreased MTSSS and an increased LTSD, were identified as independent risk factors for noncontact ACL injuries. These findings will help clinicians identify individuals at high risk of ACL injury and facilitate the development of targeted prevention strategies.

LEVEL OF EVIDENCE

Level III.

Reported Anterior Cruciate Ligament Injury Incidence in Adolescent Athletes Is Greatest in Female Soccer Players and Athletes Participating in Club Sports: A Systematic Review and Meta-analysis

PURPOSE

To identify the risk of anterior cruciate ligament (ACL) injury in adolescent athletes based on sex, sport, and sport affiliation.

METHODS

A literature search was performed using 3 online databases (PubMed, Cochrane Library, and EMBASE) from database inception to November 2023 per the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included studies consisted of Level I or II studies reporting on ACL injury exposures in time (hours) or injuries per 1,000 athlete-exposures (AEs) (1 game or practice) in adolescent athletes. Exclusion criteria consisted of non-English studies, case reports, animal/cadaveric studies, and review articles. Methodological quality and bias assessment of the included studies was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. ACL injuries were analyzed and pooled to calculate incidence rates (IRs), per-season risk, and relative risk (RR) based on sex, sport, and sport affiliation (club sport participation vs school sport participation).

RESULTS

A total of 1,389 ACL injuries over 19,134,167 AEs were identified (IR, 0.075; 95% confidence interval [CI], 0.071-0.079). Of these, 670 ACL injuries were reported in female athletes over 7,549,892 AEs (IR, 0.089; 95% CI, 0.087-0.091) with 719 in males over 11,584,275 AEs (IR, 0.062; 95% CI, 0.058-0.067). The greatest RR for ACL injury in females was in soccer (RR, 3.12; 95% CI, 2.58-3.77) for AEs. The greatest per-season risk of ACL injuries reported in female athletes occurred in soccer (1.08%), basketball (1.03%), and gymnastics (1.01%). The greatest per-season risk of ACL injuries reported in male athletes occurred in football (0.82%), lacrosse (0.64%), and soccer (0.35%). Club sport participation, in both AEs (RR, 3.94; 95% CI, 3.19-4.87) and hours of exposure (RR, 1.57; 95% CI, 1.07-2.28), demonstrated an increased risk of ACL injury.

CONCLUSIONS

The risk of ACL injuries was 1.56-fold greater in adolescent female athletes compared with male athletes. The highest-risk sport for females was soccer. Participation in club sports possessed higher rates of injury compared with school sports.

LEVEL OF EVIDENCE

Level II; meta-analysis of Level I and II studies.

What impact have the IOC medical consensus statements made on athlete health? A survey of medical commissions from National Olympic/Paralympic Committees and International Sports Federations

Background

The International Olympic Committee (IOC) Medical and Scientific Commission has supported collating and sharing evidence globally by developing sports medicine consensus statements ('Statements''). Publishing the Statements requires substantial resources that must be balanced by use and impact on policy and practice. This study aimed to gain a better understanding of awareness and uptake of the Statements globally through a survey of the National Olympic Committees (NOC), National Paralympic Committees (NPC) and International Federations (IF).

Method

A cross-sectional survey of medical commission representatives from NOCs/NPCs/IFs. A structured questionnaire was distributed through the IOC head office, informed by prior research. Questions comprised a mix of closed and open-text responses with results presented descriptively by organisation type and total.

Results

55 responses were included: 29 (52%) from NOC/NPC representatives (response rate 14%) and 26 (47%) from IF representatives (response rate 63%). All Statements had been used by at least one respondent, with the Statement addressing concussion ranked highest (used by 33/55). The main barriers to use were financial limitations (n=21), club/sport culture and behaviours (n=19) and lack of understanding from coaches/team sport personnel (n=19). Participants believed the Statements were a successful strategy for improving athlete health (n=39/51 agree or strongly agree).

Conclusion

There was clear support for the continued development of sports medicine guidance, including in the format of these Statements. To ensure Statements lead to demonstrable health benefits for athletes, input from athletes, coaches and supporting staff is needed, as well as clearer identification of the purpose and audience of each topic developed.

Team Approach: Neuromuscular Training for Primary and Secondary Prevention of Anterior Cruciate Ligament Injury

Neuromuscular training is a method of performance optimization-typically combining plyometrics, balancing training, agility, and dynamic stabilization-predicated on improving the efficiency of fundamental movement patterns. Neuromuscular training has consistently been shown to reduce the risk of anterior cruciate ligament injury, particularly for athletes engaged in activities associated with noncontact knee injuries (i.e., women's soccer). Successful implementation of neuromuscular training programs requires input from coaches, physical therapists, athletic trainers, and physicians to generate efficacious programs with high rates of adherence.

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

OBJECTIVES

We evaluated the implementation of Prep-to-Play PRO, an injury prevention programme for women's elite Australian Football League (AFLW).

METHODS

The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) of Prep-to-Play PRO were assessed based on the proportion of AFLW players and/or staff who: were aware of the programme (R), believed it may reduce anterior cruciate ligament injury (E), attempted to implement any/all programme components (A), implemented all intended components as practically as possible (I) and intended future programme implementation (M). Quantitative and qualitative data were triangulated to assess 58 RE-AIM items (evidence of yes/no/unsure/no evidence) and the 5 RE-AIM dimensions (fully achieved=evidence of yes on >50% dimension items, partially achieved=50% of items evidence of yes and 50% unsure or 50% mix of unsure and unanswered, or not met=evidence of yes on <50% dimension items).

RESULTS

Multiple sources including AFLW training observations (n=7 total), post-implementation surveys (141 players, 25 staff), semistructured interviews (19 players, 13 staff) and internal programme records (9 staff) contributed to the RE-AIM assessment. After the 2019 season, 8 of 10 (80%) AFLW clubs fully met all five RE-AIM dimensions. All 10 clubs participating in the AFLW fully achieved the reach (R) dimension. One club partially achieved the implementation (I) dimension, and one club partially achieved the effectiveness (E) and adoption (A) dimensions.

CONCLUSION

The Prep-to-Play PRO injury prevention programme for the AFLW achieved high implementation, possibly due to the programme's deliberately flexible approach coupled with our pragmatic definition of implementation. Engaging key stakeholders at multiple ecological levels (organisation, coaches, athletes) throughout programme development and implementation likely enhanced programme implementation.

An 8-week injury prevention exercise program combined with change-of-direction technique training limits movement patterns associated with anterior cruciate ligament injury risk

Knee ligament sprains are common during change-of-direction (COD) maneuvers in multidirectional team sports. This study aimed to compare the effects of an 8-week injury prevention exercise program containing COD-specific exercises and a similar program containing linear sprint exercises on injury- and performance-related variables during a 135° COD task. We hypothesized that the COD-specific training would lead to (H1) stronger reductions in biomechanical variables associated with anterior cruciate ligament (ACL) injury risk during COD, i.e. knee abduction moment and angle, hip internal rotation angle and lateral trunk lean, and (H2) more effective improvements in COD performance according to the COD completion time, executed angle, ground contact time, and approach speed. Twenty-two sports science students (40% female) completed biomechanical assessments of COD movement strategies before and after participating in two supervised 25-min training sessions per week over 8 weeks. We observed significant 'training x group' interaction effects in support of H1: the COD-specific training but not the linear sprint training led to reduced peak knee abduction moments (interaction, p = 0.027), initial knee abduction (interaction, p < 0.001), and initial lateral trunk lean angles (interaction, p < 0.001) compared to baseline. Although the COD-specific training resulted in sharper executed angles (interaction, p < 0.001), the sprint-specific training group showed reduced COD completion (interaction, p = 0.037) and ground contact times (interaction, p < 0.001). In conclusion, a combination of generic and COD-specific injury prevention training resulted in COD technique adaptations that can help to avoid ACL injury-prone COD movements but may negatively affect COD speed.

Enhancing Muscle Strength Post Anterior Cruciate Ligament Reconstruction: A Case Report Assessing the Effectiveness of Russian Current

The effectiveness of Russian electrical stimulation in enhancing muscular strength after anterior cruciate ligament (ACL) restoration is examined in this case study. In addition to traditional physiotherapy, a 29-year-old male athlete having ACL repair took part in a Russian contemporary rehabilitation regimen. Subjective evaluations of pain and functional tests all showed a substantial increase in muscular strength following the intervention. The Russian current's distinct waveform and high-frequency bursts appeared to improve neuromuscular control and quicken the activation of skeletal muscle in the excitation-contraction phase. The evaluation conducted after the intervention revealed notable enhancements in muscular strength and scores on the lower extremity functional scale. The initial score of 32, indicating a moderate functional limitation, improved to 64, indicating a minimal functional limitation. Additionally, the use of Russian electrical stimulation in ACL rehabilitation programs resulted in a reduction in pain levels from 9/10 to 3/10, as measured by the visual analog scale. These findings suggest that the implementation of Russian electrical stimulation shows promise in ACL rehabilitation. However, to validate and further explore these results, it is necessary to conduct larger-scale research studies and randomized controlled trials.

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

OBJECTIVES

The aim of our study was to explore the contextual factors that affect the implementation of football injury prevention initiatives and the provision of effective injury management in the Irish Women's National League (WNL).

METHODS

We used a criterion-based purposive sampling approach to recruit coaches (n=7), players (n=17) and medical personnel (n=8) representing eight of the nine clubs in the WNL to participate in one-to-one semistructured interviews. Our study was located within an interpretivist, constructivist research paradigm. The interview data were analysed using reflexive thematic analysis.

RESULTS

The participants identified academic and work pressures, financial challenges, conflict with college football, inadequate facilities and gender inequity as being barriers to the implementation of injury prevention initiatives and the provision of effective injury management. Financial constraints within clubs were perceived to limit the provision of medical care and strength and conditioning (S&C) support and this was deemed to be associated with a heightened risk of injuries.

CONCLUSION

Specific contextual factors were identified which curtail the implementation of injury prevention initiatives and the provision of effective injury management in elite-level women's club football in Ireland. Gender inequity was identified as one of the factors impacting the availability of high-quality medical care, S&C support, as well as access to training and match facilities. Our results provide new insights that could be used to inform the design and implementation of injury prevention and management initiatives for women football players in Ireland.

Epidemiology of Anterior Cruciate Ligament Tears in National Collegiate Athletic Association Athletes: 2014/2015-2018/2019

PURPOSE

This study aimed to describe the epidemiology of ACL tears in NCAA men's and women's sports.

METHODS

Injury and exposure data collected within the NCAA Injury Surveillance Program from 2014/2015 to 2018/2019 were analyzed. ACL tear frequencies, injury rates (IR), and injury proportions were used to describe injury incidence by sport, event type, injury mechanism, and injury history. Injury rate ratios (IRR) were used to examine differential injury rates, and injury proportion ratios (IPR) were used to examine differential distributions.

RESULTS

A total of 729 ACL tears were reported from 8,474,401 recorded athlete exposures (AE) during the study period (IR = 0.86 per 10,000 AE), and the competition-related ACL tear rate was higher than the practice-related rate (IRR = 5.52, 95% confidence interval [CI] = 4.75-6.39). Among men's sports, the highest overall ACL tear rate was observed in men's football (IR = 1.44 per 10,000 AE), whereas among women's sports, the highest overall rate was observed in women's soccer (IR = 2.60 per 10,000 AE). Among sex-comparable sports, ACL tear rates were higher in women's basketball, softball, and soccer, as compared with their men's counterparts. ACL tears were more prevalently attributed to player contact mechanisms in men's sports than women's sports (IPR = 1.73, 95% CI = 1.37-2.19), but more prevalently attributed to noncontact mechanisms in women's sports than men's sports (IPR = 1.17, 95% CI = 1.01-1.35).

CONCLUSIONS

ACL tear risk in women's sports continues to warrant attention and prevention efforts. Given the differential rates by event type, future research efforts may also evaluate initiatives to reduce competition-related injury burden in NCAA sports.

Development of a Cutting Technique Modification Training Program and Evaluation of its Effects on Movement Quality and Cutting Performance in Male Adolescent American Football Players

This study developed a cutting technique modification training program and investigated its effects on cutting performance and movement quality in adolescent American football players. For six weeks, an intervention group (IG) of 11 players participated in 25 min cutting technique modification training sessions integrated into team training twice a week, while a control group (CG) of 11 players continued their usual team training. Movement quality was assessed by evaluating 2D high-speed videos, obtained during preplanned 45° and 90° cutting tests, using the Cutting Movement Assessment Score (CMAS) qualitative screening tool. Cutting performance was assessed based on change of direction deficit (CODD). Significant interaction effects of time × group were found for CMAS in 45° and 90° cuttings (p < 0.001, ηp2 = 0.76, p < 0.001, ηp2 = 0.64, respectively), with large improvements in the IG (p < 0.001, g = -2.16, p < 0.001, g = -1.78, respectively) and deteriorations in the CG for 45° cuttings (p = 0.002, g = 1.15). However, no statistically significant differences in CODD were observed pre-to-post intervention. The cutting technique modification training was effective at improving movement quality without impairing cutting performance, and it can be used by practitioners working with adolescent athletes.

Identifying modifiable risk factors and screening strategies associated with anterior cruciate ligament injury risk in children aged 6 to 13 years: A systematic review

Growing anterior cruciate ligament (ACL) injury incidence is reported in countries across Europe, North America and in Australia for 5-14-year-olds, yet research on injury risk reduction predominantly focuses on populations aged > 13 years. For injury risk reduction, it is crucial to understand (i) which modifiable risk factors are associated with ACL injury in children (6-13 years) and (ii) how these risk factors are assessed. Articles were grouped according to sex/gender and/or maturational/age differences and examined modifiable risk factors during different physical screening tasks. The included articles (n = 40) predominantly examined intrinsic risk factors in girls aged 10-13 years. Factors mechanically linked to increased ACL loading at this age included increased peak knee adductor moments, knee valgus angles, hip and knee extension, and ground reaction forces. Assessment focused on laboratory-based assessments (e.g., motion capture, force plates). This review concluded that modifiable risk factors are present in children aged 6-13 years and that injury risk reduction strategies should be implemented as early as possible regardless of sex/gender. Further, screening strategies need updating to be childhood specific and feasible for the wide community. Additional research on extrinsic risk factors, norm values and children aged 6-9 years could allow for more targeted risk reduction strategies.

Return to active duty after anterior cruciate ligament reconstruction (ACLR) in Chinese male military aircrews

Background

Surgically treated anterior cruciate ligament (ACL) injuries may be a waivable condition and allow return to full flight status, but waivers are based on expert opinion rather than recent published data. The purpose of this study was to evaluate return to flight after anterior cruciate ligament reconstruction (ACLR) in male military aircrews with ACL injuries and to identify factors that affect flight clearance.

Method

A single-center retrospective review was conducted by the authors for all active-duty aircrew who underwent ACLR at an authorized military medical center from January 2010 to December 2019. Demographic characteristics, occupational information, surgical data, and flight readiness evaluation outcomes were collected. Based on the final medical evaluation, subjects were divided into a qualified group (N = 64) and a disqualified group (N = 9), and the difference in data collected between the two groups was then analyzed to identify factors affecting flight clearance.

Results

A total of 73 patients underwent successful ACLR with a mean age of 31.6 ± 5.6 years. Non-contact injury was the main type of ACL injury, accounting for 84.9% of the total injuries. 55 cases (75.3%) occurred during daily sports activities and 18 (24.7%) during military training. 64 of the 73 crewmembers (87.7%) were able to return to flight at their last follow-up evaluation. The preoperative interval time (PIT) was significantly less in the qualified group than in the disqualified group (P = 0.002). Patients who underwent ACLR within three months were more likely to return to flying than those who underwent the procedure three months later (97.4% vs. 76.5%, P = 0.010). The incidence of failure to return to flight duty was significantly higher in aircrews with ACL injuries combined with meniscal injuries than in aircrews with isolated ACL injuries (21.4% vs. 0.0%, P = 0.017).

Conclusion

ACLR appears to be safe for military aircrew suffering ACL injuries with or without meniscal injury, and return to flight status is the most likely outcome for the majority of postoperative pilots. Prolonged PIT, PIT > 3 months, and ACL injury combined with meniscus injury had a negative impact on postoperative flight readiness.

Secondary Anterior Cruciate Ligament Injury Prevention Training in Athletes: What Is the Missing Link?

After reconstruction, the return to full competition rate of athletes is low, while the re-injury rate remains high despite the completion of a rehabilitation programme. Primary ACL prevention programmes are well developed, yet few research papers focus on secondary ACL injury prevention. The aim of current review is to determine if current ACL secondary prevention training has a positive influence on the re-injury rate, the clinical or functional outcomes, or the risk of re-injury in athletes. Studies investigating secondary prevention of ACL were searched in PubMed and EBSCOhost, followed by a review of the references in the identified articles. The existing evidence suggests that neuromuscular training, eccentric strengthening, and plyometric exercises may have a potential impact on improving biomechanical, functional, and psychological outcomes in athletes; however, the studies on the prevention of second ACL injury in athletes is scarce and inconclusive. Future research is needed to investigate the effectiveness of secondary ACL prevention in reducing the re-injury rates. (PROSPERO Registration number: CRD42021291308).

What is needed to reduce the risk of anterior cruciate ligament injuries in children? - Hearing from experts

OBJECTIVE

Anterior cruciate ligament (ACL) injuries are an emerging health problem in children. Acknowledging considerable gaps in knowledge, the aim of this study was to examine the current knowledge on childhood ACL injury, and to explore risk assessment and reduction strategies, with experts in the research community.

DESIGN

Qualitative study; semi-structured expert interviews.

METHODS

Interviews with seven international, multidisciplinary academic experts were conducted from February until June 2022. A thematic analysis approach organized verbatim quotes into themes using Nvivo Software.

RESULTS

Gaps in knowledge on the actual injury mechanism, and influence of physical activity behaviours, constrain targeted risk assessment and reduction strategies in childhood ACL injuries. Strategies to examine and reduce the risk of ACL injury included: examining an athletes' whole-body performance, moving from constraint (e.g., squat) to less constraint (e.g., single-leg) tasks, making assessments into children's context, building a movement repertoire at young age, performing risk reduction programs, multiple sports, and prioritising rest.

CONCLUSION

Research is urgently warranted on the actual injury mechanism, reasons for ACL injuries in children, and potential risk factors to update risk assessment and reduction strategies. Further, educating stakeholders on risk reduction strategies could be essential to address the increasing occurrence of childhood ACL injuries.

Exercise-Based Knee and Anterior Cruciate Ligament Injury Prevention

The Academy of Orthopaedic Physical Therapy and the American Academy of Sports Physical Therapy have an ongoing effort to create evidence-based clinical practice guidelines (CPGs) for orthopaedic and sports physical therapy management and prevention of musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability and Health (ICF). This guideline focuses on the exercise-based prevention of knee injuries and provides an update on the 2018 guideline, J Orthop Sports Phys Ther. 2018;48(9):A1-A42. doi:10.2519/jospt.2018.0303 J Orthop Sports Phys Ther. 2023;53(1):CPG1-CPG34. doi:10.2519/jospt.2023.0301.

The Safe Landing warm up technique modification programme: An effective anterior cruciate ligament injury mitigation strategy to improve cutting and jump-movement quality in soccer players

The objective of the study was to evaluate the effectiveness of the Safe Landing (SL), a 6-week technique-modification (TM) programme, on cutting and jump-landing movement quality in football players. In a non-randomized design, 32 male semi-professional football players from two Spanish clubs participated in the study: one served as the control group (CG, n = 11), while the other performed the SL (n = 15). Performance and movement quality of drop vertical jump and 70º change of direction (COD70) were evaluated through 2D video footage pre- and post-intervention. In such tasks, the Landing Error Scoring System for first (LESS1) and second (LESS2) landings, and the Cutting Movement Assessment Score (CMAS) were used for assessing movement quality. Pre-to-post changes and baseline-adjusted ANCOVA were used. Medium-to-large differences between groups at post-test were shown in CMAS, LESS1 and LESS2 (p < 0.082, ղ2 = 0.137-0.272), with small-to-large improvements in SL (p < 0.046, ES=0.546-1.307), and CG remaining unchanged (p > 0.05) pre-to-post. In COD70 performance, large differences were found between groups (p < 0.047, ղ2 = 0.160-0.253), with SL maintaining performance (p > 0.05, ES=0.039-0.420), while CG moderately decreasing performance (p = 0.024, ES=0.753) pre-to-post. The SL is a feasible and effective TM program to improve movement quality and thus potential injury risk in cutting and landing, while not negatively affecting performance.

Unanticipated fake-and-cut maneuvers do not increase knee abduction moments in sport-specific tasks: Implication for ACL injury prevention and risk screening

Non-contact anterior cruciate ligament injuries typically occur during cutting maneuvers and are associated with high peak knee abduction moments (KAM) within early stance. To screen athletes for injury risk or quantify the efficacy of prevention programs, it may be necessary to design tasks that mimic game situations. Thus, this study compared KAMs and ranking consistency of female handball players in three sport-specific fake-and-cut tasks of increasing complexity. The biomechanics of female handball players (n = 51, mean ± SD: 66.9 ± 7.8 kg, 1.74 ± 0.06 m, 19.2 ± 3.4 years) were recorded with a 3D motion capture system and force plates during three standardized fake-and-cut tasks. Task 1 was designed as a simple pre-planned cut, task 2 included catching a ball before a pre-planned cut in front of a static defender, and task 3 was designed as an unanticipated cut with three dynamic defenders involved. Inverse dynamics were used to calculate peak KAM within the first 100 ms of stance. KAM was decomposed into the frontal plane knee joint moment arm and resultant ground reaction force. RANOVAs (α ≤ 0.05) were used to reveal differences in the KAM magnitudes, moment arm, and resultant ground reaction force for the three tasks. Spearman's rank correlations were calculated to test the ranking consistency of the athletes' KAMs. There was a significant task main effect on KAM (p = 0.02; ηp2 = 0.13). The KAM in the two complex tasks was significantly higher (task 2: 1.73 Nm/kg; task 3: 1.64 Nm/kg) than the KAM in the simplest task (task 1: 1.52 Nm/kg). The ranking of the peak KAM was consistent regardless of the task complexity. Comparing tasks 1 and 2, an increase in KAM resulted from an increased frontal plane moment arm. Comparing tasks 1 and 3, higher KAM in task 3 resulted from an interplay between both moment arm and the resultant ground reaction force. In contrast to previous studies, unanticipated cutting maneuvers did not produce the highest KAMs. These findings indicate that the players have developed an automated sport-specific cutting technique that is utilized in both pre-planned and unanticipated fake-and-cut tasks.

Preliminary Report on the Train the Brain Project, Part II: Neuroplasticity of Augmented Neuromuscular Training and Improved Injury-Risk Biomechanics

CONTEXT

Neuromuscular training (NMT) facilitates the acquisition of new movement patterns that reduce the anterior cruciate ligament injury risk. However, the neural mechanisms underlying these changes are unknown.

OBJECTIVE

To determine the relationship between brain activation and biomechanical changes after NMT with biofeedback.

DESIGN

Cohort study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty female high school soccer athletes, with 10 in an augmented NMT group and 10 in a control (no training) group.

MAIN OUTCOME MEASURE(S)

Ten participants completed 6 weeks of NMT augmented with real-time biofeedback to reduce knee injury-risk movements, and 10 participants pursued no training. Augmented neuromuscular training (aNMT) was implemented with visual biofeedback that responded in real time to injury-risk biomechanical variables. A drop vertical jump with 3-dimensional motion capture was used to assess injury-risk neuromuscular changes before and after the 6-week intervention. Brain-activation changes were measured using functional magnetic resonance imaging during unilateral knee and multijoint motor tasks.

RESULTS

After aNMT, sensory (precuneus), visual-spatial (lingual gyrus), and motor-planning (premotor) brain activity increased for knee-specific movement; sensorimotor cortex activity for multijoint movement decreased. The knee-abduction moment during landing also decreased (4.66 ± 5.45 newton meters; P = .02; Hedges g = 0.82) in the aNMT group but did not change in the control group (P > .05). The training-induced increased brain activity with isolated knee movement was associated with decreases in knee-abduction moment (r = 0.67; P = .036) and sensorimotor cortex activity for multijoint movement (r = 0.87; P = .001). No change in brain activity was observed in the control group (P > .05).

CONCLUSIONS

The relationship between neural changes observed across tasks and reduced knee abduction suggests that aNMT facilitated recruitment of sensory integration centers to support reduced injury-risk mechanics and improve sensorimotor neural efficiency for multijoint control. Further research is warranted to determine if this training-related multimodal neuroplasticity enhances neuromuscular control during more complex sport-specific activities.

Exercise-Based Training Strategies to Reduce the Incidence or Mitigate the Risk Factors of Anterior Cruciate Ligament Injury in Adult Football (Soccer) Players: A Systematic Review

Anterior cruciate ligament (ACL) is one of the most concerning injuries for football players. The aim of this review is to investigate the effects of exercise-based interventions targeting at reducing ACL injury rate or mitigating risk factors of ACL injury in adult football players. Following PRISMA guidelines, a systematic search was conducted in CINAHL, Cochrane Library, PubMed, Scopus, SPORTDiscus and Web of Science. Studies assessing the effect of exercise-based interventions in ACL injury incidence or modifiable risk factors in adult football players were included. 29 studies evaluating 4502 male and 1589 female players were included (15 RCT, 8 NRCT, 6 single-arm): 14 included warm-up, 7 resistance training, 4 mixed training, 3 balance, 1 core stability and 1 technique modification interventions. 6 out of 29 studies investigated the effect of interventions on ACL injury incidence, while the remaining 23 investigated their effect on risk factors. Only 21% and 13% studies evaluating risk of injury variables reported reliability measures and/or smallest worthwhile change data. Warm-up, core stability, balance and technique modification appear effective and feasible interventions to be included in football teams. However, the use of more ecologically valid tests and individually tailored interventions targeting specific ACL injury mechanisms are required.