Correlation of biomechanical variables of lower extremity movement during functional tests and functional tasks in a population of youth league football players: a cross-sectional correlation study (Preprint)

Abstract

BACKGROUND Football, the world's most popular sport, carries significant injury risks, especially for youth players. Real-time monitoring of movement patterns is crucial for reducing these risks. Traditional methods often require multiple sensor systems to measure various biomechanical parameters, making the process complex and challenging. The DAid® smart sock system offers a user-friendly alternative, but its effectiveness as a standalone tool for comprehensive lower extremity monitoring requires validation. OBJECTIVE This study aims to investigate the correlations between biomechanical variables of lower extremity movements during the "Single Leg Squat" functional test and its variations in youth league football players, using wireless sensor systems in field tests. METHODS Thirty-two youth league football players (aged 14-15; 16 males, 16 females) participated in the study, performing the "Single Leg Squat" test and its variations using the NOTCH® inertial sensor system, DAid® smart socks, and PLUX Wireless Biosignals (muscleBAN kit). Correlations between lower limb biomechanical variables were analysed using data from these systems. RESULTS The study found a strong positive correlation between hip adduction and changes in the centre of pressure on the medial plantar surface (COP1X: r=0.785, p<.001). Hip internal rotation also showed a significant positive correlation with centre of pressure changes (COPY1: r=0.585, p<.01). CONCLUSIONS Significant correlations exist between the foot centre of pressure, lower limb movement, and muscle activity during the "Single Leg Squat". These findings demonstrate the relevance of the wireless sensor systems used in this study for assessing correlations in lower limb biomechanics in football players, with the DAid® smart sock system serving as one of the tools to facilitate this assessment.