Effects of maturation on knee biomechanics during cutting and landing in young female soccer players

Maturation and biomechanical risk factors associated with anterior cruciate ligament injury: Is there a link? A systematic review

OBJECTIVE

To establish the potential link between sex-specific maturation and biomechanical factors associated with ACL injury during dynamic tasks.

DESIGN

Systematic review.

LITERATURE SEARCH

Five databases (CINHAL®, Cochrane Library, PubMed®, Scopus®, and SPORTDiscus) were searched and monitored until 27 May 2024.

STUDY SELECTION CRITERIA

Cross-sectional, cohort, case-control, or interventional studies reporting one or more biomechanical variable linked with ACL injury and which assessed participants across two or more maturation phases were considered eligible.

DATA SYNTHESIS

Studies were assessed for risk of bias using a modified version of the Newcastle Ottawa Scale and overall quality of evidence was rated using GRADE. Metrics and effect sizes were presented where available.

RESULTS

Eighteen included studies examined 400 males, 1377 females, and 315 participants of undefined sex across various maturation phases. The methodological quality of most studies (n = 16) was considered good, and satisfactory for two. Knee abduction angle, knee abduction moment, knee flexion angle, and ground reaction forces were most commonly reported. Knee abduction angles and moments and knee flexion angles were greater in late and post-pubertal females than males and pre-pubertal females during both landing and cutting tasks. When normalised for body mass, ground reaction forces were generally greater in males compared to females overall and for less mature participants for both sexes. Overall quality of evidence was low or medium across the four biomechanical measures.

CONCLUSION

Sex-specific maturation considerations are important in the targeted development and implementation of ACL injury risk identification and prevention strategies.

Changes in Lower Limb Biomechanics Across Various Stages of Maturation and Implications for ACL Injury Risk in Female Athletes: a Systematic Review

BACKGROUND

Female athletes are four to six times more likely to sustain an anterior cruciate ligament (ACL) injury than male athletes. Jump-landing biomechanics are influenced by maturation, with post-pubertal female athletes at a heightened risk of ACL injuries.

OBJECTIVE

The aim of our systematic review was to identify and summarise the current evidence regarding the changes in kinematic and kinetic risk factors associated with ACL injuries during jump-landing tasks in female athletes at various stages of maturity.

METHODS

A systematic search was conducted in PubMed, CINAHL, Web of Science, SPORTDiscus, EMBASE and Scopus. Articles were included if they: (1) conducted the research on uninjured female athletes with no restriction on playing level/experience; (2) provided information regarding the stage of the maturity and the scale used for estimating the maturity status of the participants; and (3) reported a biomechanical risk factor associated with ACL injuries during jump-landing tasks across at least two different maturity groups (e.g. pre-pubertal vs post-pubertal).

RESULTS

Sixteen articles involving 2323 female athletes were included in our review. A total of 12 kinematic and 8 kinetic variables were identified across these studies. Of the 12 kinematic variables reported in our review, we found strong evidence for higher peak knee abduction angle in post-pubertal female individuals compared with pre-pubertal girls (p < 0.05). With regard to the 8 kinetic variables, we found strong evidence for lower relative peak vertical ground reaction force, higher external knee abduction moment and internal rotation moment in post-pubertal compared with pre-pubertal athletes. The strength of evidence for the remaining kinematic and kinetic variables ranged from conflicting to moderate and, in some instances, could not be determined.

CONCLUSIONS

Our study provides an overview of the changes in biomechanical risk factors in female athletes during jump-landing tasks at various stages of maturity. We found moderate-to-limited evidence for most kinematic and kinetic variables, highlighting the need for further research.

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.

Predictive simulation of single-leg landing scenarios for ACL injury risk factors evaluation

The Anterior Cruciate Ligament (ACL) rupture is a very common knee injury during sport activities. Landing after jump is one of the most prominent human body movements that can lead to such an injury. The landing-related ACL injury risk factors have been in the spotlight of research interest. Over the years, researchers and clinicians acquire knowledge about human movement during daily-life activities by organizing complex in vivo studies that feature high complexity, costs and technical and most importantly physical challenges. In an attempt to overcome these limitations, this paper introduces a computational modeling and simulation pipeline that aims to predict and identify key parameters of interest that are related to ACL injury during single-leg landings. We examined the following conditions: a) landing height, b) hip internal and external rotation, c) lumbar forward and backward leaning, d) lumbar medial and lateral bending, e) muscle forces permutations and f) effort goal weight. Identified on related research studies, we evaluated the following risk factors: vertical Ground Reaction Force (vGRF), knee joint Anterior force (AF), Medial force (MF), Compressive force (CF), Abduction moment (AbdM), Internal rotation moment (IRM), quadricep and hamstring muscle forces and Quadriceps/Hamstrings force ratio (Q/H force ratio). Our study clearly demonstrated that ACL injury is a rather complicated mechanism with many associated risk factors which are evidently correlated. Nevertheless, the results were mostly in agreement with other research studies regarding the ACL risk factors. The presented pipeline showcased promising potential of predictive simulations to evaluate different aspects of complicated phenomena, such as the ACL injury.

Injury incidence and risk factors in youth soccer players: a systematic literature review. Part II: Intrinsic and extrinsic risk factors

Injury is defined as a complex phenomenon determined by the non-linear interaction of several intrinsic and extrinsic factors. The objective of the present study was to perform a systematic literature review on the injury risk factors in young soccer players. After electronic database searching, articles in line with the inclusion criteria were selected for the systematic review. Injury risk factor data were extracted and grouped in intrinsic and extrinsic risk factors. The main findings of the current review are as follows: (1) alteration in neuromuscular control such as limb asymmetry and dynamic knee valgus are important intrinsic risk factors; (2) maturation status may impair neuromuscular control and increase the risk of injury; (3) fatigue and poor recovery contribute to the onset of overuse injuries; (4) the impact of anthropometric factors is still unclear; (5) previous injuries increase the risk of re-injuries; (6) highly skilled players are more exposed to risk of injuries; (7) high external workloads increase the risk of injuries; (8) playing position, as well as sport specialization, exposes young soccer players to greater injury risk. Many factors (e.g., neuromuscular control, training load, maturity status) can modify the susceptibility to injury in young soccer players. Being aware of the complex interaction between these factors is essential to identify players at higher risk of injury, develop adequate prevention strategies, and from a scientific point of view move from a reductionist to a complex system approach.

Age- and Sex-Specific Joint Biomechanics in Response to Partial and Complete Anterior Cruciate Ligament Injury in the Porcine Model

CONTEXT

Pediatric anterior cruciate ligament (ACL) injury rates are increasing and are highest in female adolescents. Complete ACL tears are typically surgically reconstructed, but few guidelines and very limited data exist regarding the need for surgical reconstruction or rehabilitation for partial ACL tears in skeletally immature patients.

OBJECTIVE

To evaluate the effects of partial (anteromedial bundle) and complete ACL transection on joint laxity and tissue forces under anterior and rotational loads in male and female stifle joints throughout skeletal growth in the porcine model.

DESIGN

Descriptive laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

We studied 60 male and female Yorkshire crossbreed pigs aged 1.5, 3, 4.5, 6, and 18 months (n = 6 pigs per age per sex).

MAIN OUTCOME MEASURE(S)

Joint laxity was measured in intact, anteromedial bundle-transected, and ACL-transected joints under applied anterior-posterior drawer and varus-valgus torque using a robotic testing system. Loading of the soft tissues in the stifle joint was measured under each condition.

RESULTS

Anterior-posterior joint laxity increased by 13% to 50% (P < .05) after anteromedial bundle transection and 75% to 178% (P < .05) after ACL transection. Destabilization after anteromedial bundle transection increased with age (P < .05) and was greater in late female than late male adolescents (P < .05). In anteromedial bundle-transected joints, the posterolateral bundle resisted the anterior load. In ACL-transected joints, the medial collateral ligament (MCL) contribution was largest, followed by the medial meniscus. The MCL contribution was larger and the medial meniscus contribution was smaller in male versus female specimens.

CONCLUSIONS

Partial ACL transection resulted in moderate increases in joint laxity, with the remaining bundle performing the primary ACL function. Destabilization due to partial ACL transection (anteromedial bundle) was largest in late adolescent joints, indicating that operative treatment should be considered in active, late-adolescent patients with this injury. Increased forces on the MCL and medial meniscus after ACL transection suggested that rehabilitation protocols may need to focus on protecting these tissues.

Sex-specific biomechanics and morphology of the anterior cruciate ligament during skeletal growth in a porcine model

Pediatric anterior cruciate ligament (ACL) injuries are on the rise, and females experience higher ACL injury risk than males during adolescence. Studies in skeletally immature patients indicate differences in ACL size and joint laxity between males and females after the onset of adolescence. However, functional data regarding the ACL and its anteromedial and posterolateral bundles in the pediatric population remain rare. Therefore, this study uses a porcine model to investigate the sex-specific morphology and biomechanics of the ACL and its bundles throughout skeletal growth. Hind limbs from male and female Yorkshire pigs aged early youth to late adolescence were imaged using magnetic resonance imaging to measure the size and orientation of the ACL and its bundles, then biomechanically tested under anterior-posterior drawer using a robotic testing system. Joint laxity decreased (p < 0.001) while joint stiffness increased (p < 0.001) throughout skeletal growth in both sexes. The ACL was the primary stabilizer against anterior tibial loading, while the functional role of the anteromedial bundle increased with age (p < 0.001), with an earlier increase in males. ACL and posterolateral bundle cross-sectional area and ACL and anteromedial bundle length were larger in males than females during adolescence (p < 0.01 for all), while ACL and bundle sagittal angle remained similar between sexes. Additionally, in situ ACL stiffness versus cross-sectional area regressions were significant across skeletal growth (r²  = 0.75, p < 0.001 in males and r²  = 0.64, p < 0.001 in females), but not within age groups. This study has implications for age and sex-specific surgical intervention strategies and suggests the need for human studies.

Lower limb injuries in an english professional football club: injury analysis and recommendations for prevention

BACKGROUND

Lower limb injuries constitute a problem in the sport of football. Our aim is to explore patterns and trends of lower limb injuries in an English professional football club.

METHODS

This is a descriptive epidemiological study. Reports provided by the club's physical therapy team were screened for injuries among professional football players sustained over four seasons, from 2015/2016 to 2018/2019. Data included setting of injury (in-match or training), anatomical location of injury, type of injury, number of days off and month of injury.

RESULTS

A total of 296 lower limb injuries were recorded in our study, with a rate of 11.14 per 1000 football hours. Injury rate during games was 51.38 per 1000 football hours, significantly greater than that during training at 3.81 per 1000 football hours (p = 0.021). The thigh was significantly the most commonly injured location at 4.67 per 1000 football hours (p < 0.001). Grade I tears were the most common injury type at 1.73 per 1000 football hours, significantly greater than grade III tears (p = 0.027), contusions (p = 0.043), fractures (p = 0.02), and lacerations (p = 0.019). Injury rates were found to be greatest during preseason and declined as season progressed. On average, an injury sidelined the affected footballer for a total of 20 days.

CONCLUSION

Lower limb injuries were more common during matches than training. The thigh is the most common injury location, and grade I muscle tear was the most common type of injury. Injury rates were higher early on in the season. Potential prevention strategies include spacing out competition, adopting training and exercise regimens that cater for recovery, and increasing research regarding injury mechanisms.

When puberty strikes: Longitudinal changes in cutting kinematics in 172 high-school female athletes

OBJECTIVES

Young female athletes involved in high-speed cutting and change-of-direction sports are particularly susceptible to anterior cruciate ligament (ACL) injuries. Little is known if maturational changes in cutting technique contribute to the increased injury risk. Our objective was to examine longitudinal changes in cutting kinematics in female athletes as they matured through puberty.

DESIGN

Longitudinal cohort study METHODS: High school female athletes (n=172) performed an unanticipated 45° cutting task in the biomechanics laboratory across two or more pubertal stages. Pubertal stages were classified using a modified Pubertal Maturational Observational Scale (pre-, mid-, or post-pubertal stages). Generalized linear mixed models were used to compare kinematics across pubertal stages.

RESULTS

As girls matured through puberty, they displayed a decrease in sagittal-plane hip (1.8-2.6°, p<0.03) and knee range-of-motion (ROM) (2.7-2.9°, p≤0.01), and decreased peak hip (2.9-3.2°, p≤0.02) and knee flexion angles (2.7-2.9°, p≤0.01), which is indicative of greater quadriceps dominance. Peak knee abduction angles also increased as girls progressed through puberty (0.9-1.4°, p≤0.02), suggesting greater ligament dominance. In terms of trunk dominance, there were mixed findings with a decrease in trunk frontal- (2.5-5.7°, p≤0.03) and sagittal-plane ROM (2.0°, p≤0.01), but an increase in trunk transverse-plane ROM (2.8-3.6°, p≤0.02) observed as girls mature. Other significant changes in cutting technique were decreased peak trunk flexion (3.8-7.8°, p≤0.01), and decreased hip flexion (2.9-3.3°, p≤0.02) and knee flexion angles (2.0-3.0°, p≤0.03) at initial contact, suggesting a more upright and stiffer cutting posture.

CONCLUSIONS

As girls mature through puberty, there is a change in cutting strategy characterized by greater quadriceps and ligament dominance.

Effects of Pubertal Maturation on ACL Forces During a Landing Task in Females

BACKGROUND

Rates of anterior cruciate ligament (ACL) rupture in young people have increased by >70% over the past two decades. Adolescent and young adult females are at higher risk of ACL injury as compared with their prepubertal counterparts.

PURPOSE

To determine ACL loading during a standardized drop-land-lateral jump in females at different stages of pubertal maturation.

STUDY DESIGN

Controlled laboratory study.

METHODS

On the basis of the Tanner classification system, 19 pre-, 19 early-/mid-, and 24 late-/postpubertal females performed a standardized drop-land-lateral jump while 3-dimensional body motion, ground-reaction forces, and surface electromyography data were acquired. These data were used to model external biomechanics, lower limb muscle forces, and knee contact forces, which were subsequently used in a validated computational model to estimate ACL loading. Statistical parametric mapping analysis of variance was used to compare ACL force and its causal contributors among the 3 pubertal maturation groups during stance phase of the task.

RESULTS

When compared with pre- and early-/midpubertal females, late-/postpubertal females had significantly higher ACL force with mean differences of 471 and 356 N during the first 30% and 48% to 85% of stance, and 343 and 274 N during the first 24% and 59% to 81% of stance, respectively, which overlapped peaks in ACL force. At the point of peak ACL force, contributions from sagittal and transverse plane loading mechanisms to ACL force were higher in late-/postpubertal compared with pre- and early-/midpubertal groups (medium effect sizes from 0.44 to 0.77). No differences were found between pre- and early-/midpubertal groups in ACL force or its contributors.

CONCLUSION

The highest ACL forces were observed in late-/postpubertal females, consistent with recently reported rises of ACL injury rates in females aged 15 to 19 years. It is important to quantify ACL force and its contributors during dynamic tasks to advance our understanding of the loading mechanism and thereby provide guidance to injury prevention.

CLINICAL RELEVANCE

Growth of ACL volume plateaus around 10 years of age, before pubertal maturation, meaning that a late-/postpubertal female could have an ACL of similar size to their less mature counterparts. However, late-/postpubertal females have higher body mass requiring higher muscle forces to accelerate the body during dynamic tasks, which may increase ACL loading. Thus, if greater forces develop in these females, in part because of their increased body mass, these higher forces will be applied to an ACL that is not proportionally larger. This may partially explain the higher rates of ACL injury in late-/postpubertal females.

Association between biological maturation and anterior cruciate ligament injury risk factors during cutting

BACKGROUND

Adolescent females are particularly susceptible to suffering anterior cruciate ligament (ACL) injuries, likely influenced by well-established maturational changes. This study investigated ACL biomechanical injury risk factors and their association with biological maturation in females.

METHODS

Thirty-five adolescent females (15 ± 1 yr) completed a series of maximum-effort 90° unanticipated cutting manoeuvres. Established biomechanical ACL injury risk factors (including external knee abduction moments, knee abduction, hip abduction, knee flexion, ground reaction force) were derived from an optoelectronic motion analysis system and force platforms, with inter-limb asymmetries in these risk factors also computed. Biological maturation (percentage of predicted adult stature) was assessed using validated regression equations, incorporating anthropometric measures of participants and their biological parents.

RESULTS

Significant bilateral asymmetries were observed with higher peak external knee abduction moments, higher ground reaction forces and less knee flexion (from 0-18% and 30-39% of contact) during the non-dominant vs. dominant cuts (effect sizes = 0.36, 0.63 and 0.50, respectively). Maturation did not appear to influence these asymmetries; however, less hip abduction was observed (e.g. 21-51% of contact for dominant cuts) in more biologically-mature females.

CONCLUSIONS

These results highlight a potential maturationrelated change in cutting technique that may explain the apparent heightened ACL injury risk in this population. As females mature, training targeted at neuromuscular control of hip abductor (e.g. gluteal) muscle groups could potentially mitigate ACL injury risk.

Growth and Maturity Status of Female Soccer Players: A Narrative Review

Reported mean ages, heights and weights of female soccer players aged <19 years in 161 studies spanning the years 1992-2020 were extracted from the literature or calculated from data available to the authors; 35 studies spanning the years 1981-2020 also included an indicator of biological maturation. Heights and weights were plotted relative to U.S. reference data. Preece-Baines Model 1 was fitted to moving averages to estimate ages at peak velocity. Maturity indicators included skeletal age, pubertal status, age at menarche, percentage of predicted adult height and predicted maturity offset. Heights and weights showed negligible secular variation across the time interval. Heights were slightly above or approximated the reference medians through 14 years old and then varied between the medians and 75th percentiles through 18 years old. Weights were above the reference medians from 9 to 18 years old. Mean ages at menarche ranged from 12.7 to 13.0 years. The trend in heights and weights suggested the persistence and/or selection of taller and heavier players during adolescence, while estimated age at peak height velocity (PHV) and ages at menarche were within the range of mean ages in European and North American samples. Data for skeletal and sexual maturity status were limited; predicted maturity offset increased linearly with mean ages and heights at prediction.

Tracking Quantitative Characteristics of Cutting Maneuvers with Wearable Movement Sensors during Competitive Women's Ultimate Frisbee Games

(1) Ultimate frisbee involves frequent cutting motions, which have a high risk of anterior cruciate ligament (ACL) injury, especially for female players. This study investigated the in-game cutting maneuvers performed by female ultimate frisbee athletes to understand the movements that could put them at risk of ACL injury. (2) Lower-body kinematics and movement around the field were reconstructed from wearable lower-body inertial sensors worn by 12 female players during 16 league-sanctioned ultimate frisbee games. (3) 422 cuts were identified from speed and direction change criteria. The mean cut had approach speed of 3.4 m/s, approach acceleration of 3.1 m/s², cut angle of 94 degrees, and ground-contact knee flexion of 34 degrees. Shallow cuts from 30 to 90 degrees were most common. Speed and acceleration did not change based on cut angle. Players on more competitive teams had higher speed and acceleration and reduced knee flexion during cutting. (4) This study demonstrates that a lower-body set of wearable inertial sensors can successfully track an athlete’s motion during real games, producing detailed biomechanical metrics of behavior and performance. These in-game measurements can be used to specify controlled cutting movements in future laboratory studies. These studies should prioritize higher-level players since they may exhibit higher-risk cutting behavior.