Role of Lower Joint Kinematics toward Jump Performance Is Adversely Impacted by Adiposity in Children

Research Objectives To examine the role of lower joint kinematics in countermovement jump performance in children, and whether that role is affected by adiposity. Design Cross-sectional study. Setting University laboratory. Participants Typically developing children; n = 21; male = 9. Interventions Not applicable. Main Outcome Measures Greater trochanter marker data was used to calculate countermovement jump height by subtracting its standing upright value from its highest value achieved during jump. Dip (Depth of the squat immediately before the start of the propulsion phase), take off velocity (ankle joint angular velocity corresponding to the last data point of the ankle joint plantarflexion), and knee angle at the propulsion onset (knee angle at the first positive data point of the knee joint angular velocity after the eccentric phase) were calculated for 3 countermovement jump trials. We chose the jump trial with the maximum jump height to analyze our outcomes. Results Adiposity was negatively related to countermovement jump height (rspearman = -0.498, p = 0.026), dip (rspearman = -0.513, p = 0.021), take off velocity (rspearman = -0.466, p = 0.038), and knee angle at the propulsive onset (rspearman = -0.534, p = 0.015). Countermovement jump height is positively related to DIP (r = 0.751, p < 0.001), take off velocity (r = 0.846, p < 0.001), and knee angle at the propulsive onset (r = -0.524, p = 0.018). Conclusions The adverse impact of adiposity in jump height may be explained by negative relationship of adiposity with the squat immediately before the start of the propulsion phase and take off velocity. This was further supported by hour findings of positive contribution of squat and take off velocity towards jump height in children. Author(s) Disclosures No conflict of interest.