Canadian Academy of Sport and Exercise Medicine position statement: Neuromuscular training programs can decrease anterior cruciate ligament injuries in youth soccer players

The Relationship Between Motor Competence and Landing Error Scoring System Performance in Youth Soccer Players

Duncan, MJ, Heering, T, Tallis, J, Guimaraes-Ferreira, L, Martins, R, Crotti, M, Barnett, L, Lander, N, and Lyons, M. The relationship between motor competence and landing error scoring system performance in youth soccer players. J Strength Cond Res 38(9): e496–e502, 2024—This study examined the relationship between motor competence (MC) and Landing Error Scoring System (LESS) performance in a sample of male junior grassroots footballers aged 10–13 years. Ninety-eight boys aged 10–13 years (mean ± SD = 11.7 ± 1 years) undertook assessment of MC, using the Test of Gross Motor Development (third edition) and anterior cruciate ligament (ACL) injury risk using the LESS. Height and mass were assessed from which maturity status was predicted. Multiple backward linear regressions indicated a significant model (p = 0.001), which explained 49% of the variance in LESS scores. Locomotor MC (β = −0.538, p = 0.001), object control MC (β = −0.261, p = 0.004), and age (β = 1.17, p = 0.03) significantly contributed to the model. Maturity offset (p = 0.100) was not significant. Analysis of covariance (controlling for age and maturity offset) indicated a significant difference in locomotor MC between those classified as poor for LESS. A similar result was observed for object control MC (p = 0.003, = 0.09), where those classed as poor for LESS had significantly poorer object control MC compared with those classed as excellent, good, and moderate. The results of this study indicate that there is a relationship between both locomotor and object control MC and errors in drop jump landing mechanics in boys aged 10–13 years, with MC explaining nearly 50% of the variance in LESS scores. Practically, this study indicates that MC, particularly locomotor MC, has potential to identify performance in jump landing tests that are associated with increased risk of ACL injury in boys who play grassroots soccer.

Evaluating the quality of systematic reviews of comparative studies in autograft-based anterior cruciate ligament reconstruction using the AMSTAR-2 tool: A systematic umbrella review

PURPOSE

There remains a lack of consensus around autograft selection in anterior cruciate ligament reconstruction (ACLR), though there is a large body of overlapping systematic reviews and meta-analyses. Systematic reviews and their methodological quality were aimed to be further assessed, using a validated tool known as assessing the methodological quality of systematic reviews (AMSTAR-2).

METHODS

MEDLINE, Embase and CENTRAL were searched from inception to 23 April 2023 for systematic reviews (with/without meta-analysis) comparing primary ACLR autografts. A final quality rating from AMSTAR-2 was provided for each study ('critically low', 'low', 'moderate' or 'high' quality). Correlational analyses were conducted for ratings in relation to study characteristics.

RESULTS

Two thousand five hundred and ninety-eight studies were screened, and 50 studies were ultimately included. Twenty-four studies (48%) were rated as 'critically low', 17 (34%) as 'low', seven (14%) as 'moderate' and two (4%) as 'high' quality. The least followed domains were reporting on sources of funding (1/50 studies), the impact of risk of bias on results of meta-analyses (11/36 studies) and publication bias (17/36 studies). There was a significant increase in the frequency of studies graded as 'moderate' compared to 'low' or 'critically low' quality over time (p = 0.020).

CONCLUSION

The methodological quality of systematic reviews comparing autografts in ACLR is low, with many studies being rated lower due to commonly absent aspects of systematic review methodology such as investigating sources of funding and publication bias. More recent studies were generally more likely to be of higher quality. Authors are advised to consult AMSTAR-2 prior to conducting systematic reviews in ACLR.

LEVEL OF EVIDENCE

Level IV.

The Lived Experience of Rehabilitation Following Anterior Cruciate Ligament Reconstructive Surgery: A Social Ecological Analysis

Purpose

To identify, using a social ecological model, the multi-level facilitators and barriers that shape the lived experience of rehabilitation following anterior cruciate ligament reconstructive (ACLR) surgery.

Method

Semi-structured interviews with 12 adults who experienced rehabilitation following ACLR surgery. Thematic analysis of qualitative data was completed following Braun and Clarke's framework.

Results

The experience of rehabilitation was influenced by intrapersonal, interpersonal, physical, institutional, community, and policy level factors.

Conclusions

A patient's ability to successfully complete a rehabilitation program, particularly home exercises, can be situated within a social and ecological context in ways that could improve patient adherence and compliance.

Effects of pubertal growth variation on knee mechanics during walking in female and male adolescents

INTRODUCTION

Puberty substantially alters the body's mechanical properties, neuromuscular control, and sex differences therein, likely contributing to increased, sex-biased knee injury risk during adolescence. Female adolescents have higher risk for knee injuries than male adolescents of similar age engaging in similar physical activities, and much research has investigated sex differences in mechanical risk factors. However, few studies address the considerable variation in pubertal growth (timing, pace), knee mechanics, and injury susceptibility within sexes, or the impact of such growth variation on mechanical injury risk.

OBJECTIVES

The present study tested for effects of variation in pubertal growth on established mechanical knee injury risk factors, examining relationships between and within sexes.

METHODS

Pubertal growth indices describing variation in the timing and rate of pubertal growth were developed using principal component analysis and auxological data from serial stature measurements. Linear mixed models were applied to evaluate relationships between these indices and knee mechanics during walking in a sample of adolescents.

RESULTS

Later developing female adolescents with slower pubertal growth had higher extension moments throughout stance, whereas earlier developers had higher valgus knee angles and moments. In male adolescents, faster and later growth were related to higher extension moments throughout gait. In both sexes, faster growers had higher internal rotation moments at foot-strike.

CONCLUSIONS

Pubertal growth variation has important effects on mechanical knee injury risk in adolescence, affecting females and males differently. Earlier developing females exhibit greater injury risk via frontal plane factors, whereas later/faster developing males have elevated risk via sagittal plane mechanisms.

Using an Affordable Motion Capture System to Evaluate the Prognostic Value of Drop Vertical Jump Parameters for Noncontact ACL Injury

BACKGROUND

Knee kinematic parameters during a drop vertical jump (DVJ) have been demonstrated to be associated with increased risk of noncontact anterior cruciate ligament (ACL) injury. However, standard motion analysis systems are not practical for routine screening. Affordable and practical motion sensor alternatives exist but require further validation in the context of ACL injury risk assessment.

PURPOSE/HYPOTHESIS

To prospectively study DVJ parameters as predictors of noncontact ACL injury in collegiate athletes using an affordable motion capture system (Kinect; Microsoft). We hypothesized that athletes who sustained noncontact ACL injury would have larger initial and peak contact coronal abduction angles and smaller peak flexion angles at the knee during a DVJ.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

102 participants were prospectively recruited from a collegiate varsity sports program. A total of 101 of the 102 athletes (99%) were followed for an entire season for noncontact ACL injury. Each athlete performed 3 DVJs, and the data were recorded using the motion capture system. Initial coronal, peak coronal, and peak sagittal angles of the knee were identified by our software.

RESULTS

Five of the 101 athletes sustained a noncontact ACL injury. Peak coronal angles were significantly greater and peak sagittal flexion angles were significantly smaller in ACL-injured athletes (P = .049, P = .049, respectively). Receiver operating characteristic (ROC) analysis demonstrated an area under the curve of 0.88, 0.92, and 0.90 for initial coronal, peak coronal, and peak sagittal angle, respectively. An initial coronal angle cutoff of 2.96° demonstrated 80% sensitivity and 72% specificity, a peak coronal angle cutoff of 6.16° demonstrated 80% sensitivity and 72% specificity, and a peak sagittal flexion cutoff of 93.82° demonstrated 80% sensitivity and 74% specificity on the study cohort.

CONCLUSION

Increased peak coronal angle and decreased peak sagittal angle during a DVJ were significantly associated with increased risk for noncontact ACL injury. Based on ROC analysis, initial coronal angle showed good prognostic ability, whereas peak coronal angle and peak sagittal flexion provided excellent prognostic ability. Affordable motion capture systems show promise as cost-effective and practical options for large-scale ACL injury risk screening.

Acute Knee Injuries in Children and Adolescents: A Review

IMPORTANCE

Knee injuries in children and adolescents are exceedingly common. When an active youth presents complaining of knee pain, the treating pediatrician should be comfortable with forming a working differential diagnosis and should be able to manage many such injuries or recognize when it is necessary to make an appropriate referral.

OBSERVATIONS

Knee injuries typically present after acute trauma. Appreciating the likely etiologies pertaining to a particular case is best achieved with a thorough history and physical examination. This review discusses the etiologies of acute injuries including fractures that are unique to skeletally immature individuals, patellar dislocations, ligamentous injuries, and meniscal tears. Imaging findings and management of these conditions are also reviewed.

CONCLUSIONS AND RELEVANCE

This review summarizes the more common acute knee injuries seen in active children and adolescents. Given how frequently such conditions present, this overview of diagnosis and management will provide a useful resource for the nonspecialist.

Lower limb injury prevention programs in youth soccer: a survey of coach knowledge, usage, and barriers

Background

Participation in youth soccer carries a significant risk of injury, most commonly non-contact injuries of the lower extremity. A growing body of research supports the use of neuromuscular interventions by teams to prevent such injuries, yet the uptake of these recommendations by soccer teams remains largely unexplored. The purposes of the study were to determine (1) the level of awareness by youth coaches of injury prevention programs and their efficacy; (2) the number of youth coaches that use these interventions; and (3) barriers and potential facilitators to implementing a sustainable injury prevention program.

Methods

Four hundred eighteen coaches of male and female youth soccer teams were emailed an online blinded survey. This survey consisted of 26 questions covering coaches’ demographics, level of training, experience with injuries among players, and use of injury prevention programs. Question development was guided by the RE-AIM Sports Setting Matrix in combination with findings from the literature review and expert experience from orthopaedic surgeons specializing in sport medicine.

Results

Of the 418 coaches contacted, 101 responded. Only 29.8% of respondents used an injury prevention program in the prior soccer season. Coaches that had completed one or more coaching courses were more likely to use an intervention. Of those that did not already use an intervention, coaches agreed or strongly agreed that they would consider using one if it could be used in place of the warm up and take no more than 20 min (74.0%), if they could access information about the exercises (84.0%), and if the exercises could be properly demonstrated (84.0%). Additionally, 84% of coaches that did not already use an intervention agreed or strongly agreed that knowing that interventions may reduce a player’s risk of injury by 45% would affect whether they would use one.

Conclusion

This study suggests that the current use and awareness of injury prevention programs is limited by a lack of communication and education between sporting associations and coaches, as well as perceived time constraints. The results also suggest that improving coaching education of injury prevention could increase the frequency of intervention use.

Electronic supplementary material

The online version of this article (10.1186/s40634-018-0160-6) contains supplementary material, which is available to authorized users.

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.

The Effect of Abdominal Muscle Activation Techniques on Trunk and Lower Limb Mechanics During the Single-Leg Squat Task in Females

CONTEXT

Females suffer 4 to 6 times more noncontact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established.

OBJECTIVE

To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females.

DESIGN

Interventional study setting: movement and posture laboratory.

PARTICIPANTS

A total of 13 healthy females (21.3 [0.88] y, 1.68 [0.07] m, and 58.27 [5.46] kg).

INTERVENTION

Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, and control), confirmed using surface electromyography.

MAIN OUTCOME MEASURES

Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles.

RESULTS

No differences were observed for peak lateral trunk displacement, peak hip adduction angle, or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in 4 of 6 muscles recorded.

CONCLUSION

The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

Injuries in Spanish female soccer players

BACKGROUND

Epidemiologic research to learn the incidence, type, location, and severity of female soccer injuries and the risk factors for sustaining a sport injury is the first step in developing preventive policies. The aim of this study was to analyze the incidence of injuries in the population of female soccer players in Spain.

METHODS

The injuries incurred by 25,397 female soccer players were registered by the medical staff of the Spanish Football Federation during 1 season. A standardized medical questionnaire was used to classify the injury according to type, severity, location, and injury mechanism. A total of 2108 injuries was reported with an incidence of 0.083 injuries per player per season. Most injuries were in the lower limbs (74.0%), mainly affecting knee (30.4%) and ankle joints (17.9%).

RESULTS

The proportion of injuries derived from contact with another player was higher during matches (33.7%) than during training (11.4%; p < 0.001). Noncontact injuries were classified as severe more frequently than were contact injuries (51.0% vs. 42.6%; p < 0.001). A higher incidence of injury was found in adult soccer players (≥18 years) vs. their counterparts younger than18 years (0.094 vs. 0.072 injuries per player per year, respectively; p < 0.001). There were no differences between age groups in any other injury variable (e.g., type, mechanism, location, or severity; p > 0.05).

CONCLUSION

Most female soccer injuries were located at the knee and ankle; the injury mechanism determined the playing time lost; and the player's age did not affect injury characteristics.

Neuromuscular Training Availability and Efficacy in Preventing Anterior Cruciate Ligament Injury in High School Sports: A Retrospective Cohort Study

OBJECTIVE

To document neuromuscular training (NMT) availability and its relationship to anterior cruciate ligament (ACL) injuries in 4 major high school sports by gender, sport, and rural/urban geography, with the hypothesis that increased exposure to NMT would be associated with fewer ACL injuries.

DESIGN

A retrospective cohort study.

SETTING

All Minnesota high schools identified in the Minnesota State High School League (MSHSL) database for fall 2014 boys' football and soccer, and girls' volleyball and soccer.

PARTICIPANTS

All high school athletic directors were surveyed to report their school's fall 2014 experience; 53.5% returned the survey reporting experience with one or more of the sports.

INTERVENTION

Athletic directors documented each sport's preseason and in-season exposure to NMT (plyometric exercises, proximal/core muscle strengthening, education and feedback regarding proper body mechanics, and aerobics) and licensed athletic trainers.

MAIN OUTCOMES

Reported ACL injuries by sport, gender and rural/urban.

RESULTS

More than two-thirds of teams incorporated facets of NMT into their sport. Among male athletes, soccer players exposed to licensed athletic trainers experienced significantly fewer ACL injuries (P < 0.005), and NMT was associated with significantly fewer ACL injuries in football (P < 0.05) and soccer (P < 0.05). Female athletes did not demonstrate similar associated improvements, with volleyball injuries associated with increased NMT (P < 0.001), and soccer injuries not associated with NMT. However, girl soccer players in rural settings reported fewer ACL injures compared with urban teams (P < 0.001).

CONCLUSIONS

Most fall high school sports teams were exposed to NMT, which was associated with fewer ACL injuries for male, but not for female athletes. Improved gender- and sport-specific preventive training programs are indicated.

Injury Prevention Exercise Programs for Professional Soccer: Understanding the Perceptions of the End-Users

OBJECTIVE

To evaluate the perceptions of professional soccer players and staff members toward injury prevention exercise programs (IPEPs).

DESIGN

Self-report survey.

SETTING

Four professional soccer teams in 4 different countries.

PARTICIPANTS

126 players, coaches, physiotherapists, and fitness coaches were invited to participate, with 72 respondents.

MAIN OUTCOME MEASURES

Web-based survey detailing perceptions of lower limb (LL) injury susceptibility and seriousness, the value of IPEPs in general, and more specifically the International Federation of Association Football (FIFA) 11+.

RESULTS

The vast majority of the respondents believed that professional soccer players are at high risk of LL injuries (93%) and that players should perform evidence-based injury prevention exercises (98%). They also agreed that LL injuries can shorten a player's career (85%), cause physical problems later in life (82%), and negatively impact on team performance (77%). However, perceptions varied across teams regarding which types of injury prevention exercises are effective, who holds responsibility for injury prevention, and when IPEPs should be performed. Specific knowledge of the FIFA 11+ was very low and 47% of respondents believed the program would need modification for use in their team.

CONCLUSIONS

Players and staff members in professional soccer teams strongly support the use of evidence-based IPEPs. However, perceptions vary considerably between teams regarding which exercises can prevent injuries, who holds the responsibility for injury prevention, and when preventive exercises should be performed. Enhancing the ultimate impact of IPEPs in professional soccer requires a detailed understanding of each team's specific implementation context.

Relationships Between Age at Menarche, Walking Gait Base of Support, and Stance Phase Frontal Plane Knee Biomechanics in Adolescent Girls

BACKGROUND

Age at menarche impacts patterns of pubertal growth and skeletal development. These effects may carry over into variation in biomechanical profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal walking.

OBJECTIVE

To test the hypothesis that earlier menarche is related to postpubertal biomechanical risk factors for knee injuries, including a wider, more immature gait base of support, and greater valgus knee angles and moments.

DESIGN

Cross-sectional observational study.

SETTING

University research facility.

PARTICIPANTS

Healthy, postmenarcheal, adolescent girls.

METHODS

Age at menarche was obtained by recall questionnaire. Pubertal growth and anthropometric data were collected by using standard methods. Biomechanical data were taken from tests of walking gait at self-selected speed. Reflective marker position data were collected with a 3-dimensional quantitative motion analysis system, and 3 force plates recorded kinetic data.

MAIN OUTCOME MEASURES

Age at menarche; growth and anthropometric measurements; base of support; static knee frontal plane angle; and dynamic knee frontal plane angles and moments during stance.

RESULTS

Earlier menarche was correlated significantly with abbreviated pubertal growth and postpubertal retention of immature traits, including a wider base of support. Earlier menarche and wider base of support were both correlated with more valgus static knee angles, more valgus knee abduction angles and moments at foot-strike, and a more valgus peak knee abduction angle during stance. Peak knee abduction moment during stance was not correlated with age at menarche or base of support.

CONCLUSIONS

Earlier menarche and its effects on growth are associated with retention of a relatively immature gait base of support and a tendency for static and dynamic valgus knee alignment. This biomechanical profile may put girls with earlier menarche at greater risk for sports-related knee injuries.

LEVEL OF EVIDENCE

Not applicable.