Eriksrud, O., Glørsen, Ø., & Westheim, F. (2024)
Congress: IOC 7th World Conference on Prevention of Injury and Illness in Sport
Background: Change of direction (CoD) is associated with performance and injury in multidirectional sports. CoD consists of different phases (initial acceleration, deceleration, and re-acceleration) where the deceleration phase impose greater loading demands and precede many lower extremity injuries (i.e., non-contact ACL). Better understanding of deceleration demands in CoD may allow for better test, rehabilitation, and injury prevention strategies. Objective: To describe and determine differences during the deceleration phase in three different CoD tests. Design: Cross-sectional. Setting: Indoor sports hall. Participants: 16 healthy male elite youth soccer players. Interventions: Players completed three different CoD tests from short to longer approach distances (5 (m505), 10 (105) and 15 m (155)) with the same re-acceleration phase (5 m) while exposed to an external load (3 kg) provided by a motorized resistance device. Main Outcome Measurements: Comparisons between tests were made based on overall, early and late deceleration phase (Figure) outcome measurements; time (s), distance (m), maximum and average velocity (m·s-1), deceleration (m·s-2), force (N/kg), power (W/kg), and impulse (N·s/kg). Test comparisons were analyzed using repeated measures ANOVA and Friedman test and corrected with Holm’s sequential Bonferroni procedure. Results: Greater approach velocities were observed in longer tests with longer time spent in the different deceleration phases. Average deceleration and force were greater in shorter tests during the overall and late deceleration phase, while average power and impulse were greater for the longer tests during the overall, early, and late deceleration phase. No difference between tests were observed for average deceleration and force in the early deceleration phase. Conclusions: Longer CoD tests impose greater power and impulse demands, while shorter tests impose greater deceleration and force demands during the deceleration phase. This information may impact how testing, training and rehabilitation is performed in multidirectional sports athletes.