The aim of the present study was to investigate if the presence of anterior cruciate ligament (ACL) injury risk factors depicted in the laboratory would reflect at-risk patterns in football-specific field data. Twenty-four female footballers (14.9 ± 0.9 year) performed unanticipated cutting maneuvers in a laboratory setting and on the football pitch during football-specific exercises (F-EX) and games (F-GAME). Knee joint moments were collected in the laboratory and grouped using hierarchical agglomerative clustering. The clusters were used to investigate the kinematics collected on field through wearable sensors. Three clusters emerged: Cluster 1 presented the lowest knee moments; Cluster 2 presented high knee extension but low knee abduction and rotation moments; Cluster 3 presented the highest knee abduction, extension, and external rotation moments. In F-EX, greater knee abduction angles were found in Cluster 2 and 3 compared to Cluster 1 (p = 0.007). Cluster 2 showed the lowest knee and hip flexion angles (p < 0.013). Cluster 3 showed the greatest hip external rotation angles (p = 0.006). In F-GAME, Cluster 3 presented the greatest knee external rotation and lowest knee flexion angles (p = 0.003). Clinically relevant differences towards ACL injury identified in the laboratory reflected at-risk patterns only in part when cutting on the field: in the field, low-risk players exhibited similar kinematic patterns as the high-risk players. Therefore, in-lab injury risk screening may lack ecological validity.
Benjaminse, A, Nijmeijer, EM, Gokeler, A, Broekhaar, DC, and Cortes, N. Motivation unraveled: giving choice to football players to improve anterior cruciate ligament injury prevention. J Strength Cond Res 38(12): e735–e743, 2024—Providing athletes some control over a training session facilitates motor skill acquisition. This is a promising concept to use in anterior cruciate ligament (ACL) injury prevention, as the key for risk reduction is to improve quality of movement. The goal of this study was to better understand why improved motor learning occurred when football players had the opportunity to choose when to receive feedback when practicing sidestep cutting (SSC) movements. Healthy male recreational football players (n 5 22, 22.9 6 1.7 years, 185.5 6 7.2 cm, 79.3 6 9.2 kg) were included and assigned to the self-control (SC) or the yoked (YK) group. The players performed anticipated and unanticipated SSC. They received video instructions and were instructed to “copy the movement of the model to the best of their ability.” During the training blocks, the SC group could ask for feedback, whereas the YK group could not. Cutting movement assessment scores (CMAS) were measured to test quality of movement and the Intrinsic Motivation Inventory was administered to measure constructs of motivation. In the anticipated condition, SC group showed better scores in immediate post and the retention test compared with pretest (p, 0.001), whereas the YK group showed worse scores in the retention test compared with immediate posttest (p 5 0.001). Perceived competence (p 5 0.017) and self-efficacy (p 5 0.032) were consistent factors that correlated with improved CMAS in the SC group. This has given us innovative insights into underlying mechanisms optimizing the quality of movement, necessary to improve current ACL injury prevention approaches.
Primary anterior cruciate ligament (ACL) injury prevention programs effectively reduce ACL injury risk in the short term. Despite these programs, ACL injury incidence is still high, making it imperative to continue to improve cur- rent prevention strategies. A potential limitation of current ACL injury prevention training may be a deficit in the transfer of conscious, optimal movement strategies rehearsed during training sessions to automatic movements required for athletic activities and unanticipated events on the field. Instructional strategies with an internal focus of attention have traditionally been utilized, but may not be optimal for the acquisition of the control of complex motor skills required for sports. Conversely, external-focus instructional strategies may enhance skill acquisition more efficiently and increase the transfer of improved motor skills to sports activities. The current article will present in- sights gained from the motor-learning domain that may enhance neuromuscular training programs via improved skill development and increased reten- tion and transfer to sports activities, which may reduce ACL injury incidence in the long term.
In societies where physical activity levels are declining, stimulating sports participation in youth is vital. While sports offer numerous benefits, injuries in youth are at an all-time high with potential long-term consequences. Particularly, women football's popularity surge has led to a rise in knee injuries, notably anterior cruciate ligament (ACL) injuries, with severe long-term effects. Urgent societal attention is warranted, supported by media coverage and calls for action by professional players. This project aims to evaluate the potential of novel artificial intelligence-based technology to enhance player monitoring for injury risk, and to integrate these monitoring pathways into regular training practice. Its success may pave the way for broader applications across different sports and injuries. Implementation of results from lab-based research into practice is hindered by the lack of skills and technology needed to perform the required measurements. There is a critical need for non-invasive systems used during regular training practice and allowing longitudinal monitoring. Markerless motion capture technology has recently been developed and has created new potential for field-based data collection in sport settings. This technology eliminates the need for marker/sensor placement on the participant and can be employed on-site, capturing movement patterns during training. Since a common AI algorithm for data processing is used, minimal technical knowledge by the operator is required. The experienced PLAYSAFE consortium will exploit this technology to monitor 300 young female football players over the course of 1 season. The successful implementation of non-invasive monitoring of football players’ movement patterns during regular practice is the primary objective of this project. In addition, the study will generate key insights into risk factors associated with ACL injury. Through this approach, PLAYSAFE aims to reduce the burden of ACL injuries in female football players.
