Altered Peak Knee Valgus during Jump-Landing among Various Directions in Basketball and Volleyball Athletes

PURPOSE: Excessive knee valgus during landing tasks is a contributing factor to knee injuries. Most studies have examined lower extremity biomechanics during the forward direction of a jump-landing task. Athletes perform many movements in the air and land in multi-directions. Therefore, the purpose of this study was to assess the peak knee valgus angle (PKVA) during one leg jump-landing in various directions. METHODS: Eighteen male basketball and volleyball athletes participated in the study. Participants performed one leg jump-landing tests from a 30 cm height platform in four directions. Knee valgus motion was measured using Vicon™ motion system. The data were analyzed with repeated measures ANOVA. RESULTS: Direction significantly (P<0.001) influenced the PKVA during landing. Significantly higher PKVA was observed for the lateral (8.8°±4.7°) direction as compared to forward (5.8°±4.6°) direction (P<0.05). The PKVA in 30° diagonal (7.5°±4.6°) and 60° diagonal (7.7°±5.7°) directions was higher than in the forward direction (P<0.05). CONCLUSION: One leg jump-landing in lateral and diagonal directions results in a higher PKVA compared to landing in a forward direction and could lead to a higher risk of knee injury.