Athletes in team sports have to quickly visually perceive actions of opponents and teammates while executing their own movements. These continuous actions are performed under time pressure and may contribute to a non-contact ACL injury. However, ACL injury screening and prevention programmes are primarily based on standardised movements in a predictable environment. The sports environment provides much greater cognitive demand because athletes must attend their attention to numerous external stimuli and inhibit impulsive actions. Any deficit or delay in attentional processing may contribute to an inability to correct potential errors in complex coordination, resulting in knee positions that increase the ACL injury risk. In this viewpoint, we advocate that ACL injury screening should include the sports specific neurocognitive demands.
Modifiable (biomechanical and neuromuscular) anterior cruciate ligament (ACL) injury risk factors have been identified in laboratory settings. These risk factors were subsequently used in ACL injury prevention measures. Due to the lack of ecological validity, the use of on-field data in the ACL injury risk screening is increasingly advocated. Though, the kinematic differences between laboratory and on-field settings have never been investigated. The aim of the present study was to investigate the lower-limb kinematics of female footballers during agility movements performed both in laboratory and football field environments. Twenty-eight healthy young female talented football (soccer) players (14.9 ± 0.9 years) participated. Lower-limb joint kinematics was collected through wearable inertial sensors (Xsens Link) in three conditions: (1) laboratory setting during unanticipated sidestep cutting at 40-50°; on the football pitch (2) football-specific exercises (F-EX) and (3) football games (F-GAME). A hierarchical two-level random effect model in Statistical Parametric Mapping was used to compare joint kinematics among the conditions. Waveform consistency was investigated through Pearson's correlation coefficient and standardized z-score vector. In-lab kinematics differed from the on-field ones, while the latter were similar in overall shape and peaks. Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found for on-field kinematics (p < 0.044). The largest differences were found during landing and weight acceptance. The biomechanical differences between lab and field settings suggest the application of context-related adaptations in female footballers and have implications in ACL injury prevention strategies. Highlights: Talented youth female football players showed kinematical differences between the lab condition and the on-field ones, thus adopting a context-related motor strategy. Lower sagittal plane range of motion, greater ankle eversion, and pelvic rotation were found on the field. Such differences pertain to the ACL injury mechanism and prevention strategies. Preventative training should support the adoption of non-linear motor learning to stimulate greater self-organization and adaptability. It is recommended to test football players in an ecological environment to improve subsequent primary ACL injury prevention programmes.
OBJECTIVE: The aim of this study was to investigate whether dynamic balance, measured with the anterior component of the Star Excursion Balance Test (SEBT-ANT), is a risk factor for ankle injuries in physical education teacher education (PETE) students.DESIGN AND SETTING: A prospective monocentre study in first-year PETE students.PARTICIPANTS: A total of 196 subjects, of which 137 men (70%) and 59 women (30%).OUTCOME MEASURES: This study consisted of measures of the SEBT-ANT at baseline (September 2015) and an injury registration procedure during a follow-up period (September 2015-June 2016). The association between the SEBT-ANT score and subsequent ankle injury was analysed with generalised estimating equations analysis at the leg level.RESULTS: Men and women had an average SEBT-ANT score of, respectively, 65.1% and 67.7% of leg length. In 20 (15%) subjects, the first injured body site involved the ankle. Across all participants, a below average SEBT-ANT score was not associated with increased ankle injury odds (OR OR=2.43, 95% CI: 0.94 to 6.29, p=0.07). In men, a below average SEBT-ANT score indicated sevenfold increased odds for ankle injury (OR=7.06, 95% CI: 1.43 to 34.92, p=0.02). In women, this relationship was not significant (OR=0.72, 95% CI: 0.19 to 2.71, p=0.62).CONCLUSIONS: Below average normalised SEBT-ANT scores were associated with sevenfold likelihood for ankle injuries in men. In contrast, no relationship was found for the SEBT-ANT score and ankle injuries in woman. These results may provide directions for the implementation of screening tools, as part of an injury prevention programme, to identify male PETE students with an increased likelihood for ankle injuries.
