Intersegmental Coordination Patterns During Heel Rise: Effects of Knee Position and Movement Phases

<b>Background/Objectives:</b> This study aimed to provide preliminary normative data on intersegmental coordination patterns during heel rises at different knee joint positions and across various phases and periods. <b>Methods:</b> Twelve 21-year-old university students from the same cohort performed heel rises in knee-extended and knee-flexed conditions. Shank and foot kinematics were recorded using the VICON Oxford Foot Model, and intersegmental coordination was analyzed using a modified vector coding technique. <b>Results:</b> The results showed that coordination patterns varied significantly between the ascending and descending phases and across the early, middle, and late periods. In the early ascending phase, knee extension exhibited in-phase coordination (shank external rotation with hindfoot inversion), resembling propulsion-related coordination in gait, whereas knee flexion displayed greater anti-phase coordination between hindfoot plantar flexion and forefoot dorsiflexion. The middle and late periods demonstrated heel-rise-specific patterns, with coordination shifting from proximal to distal dominance. Knee flexion altered the coordination between the shank and hindfoot and between the hindfoot and forefoot in the sagittal plane compared to that during knee extension. <b>Conclusions:</b> These findings suggest that the knee position influences intersegmental coordination during heel rises, and the present results provide reference values that can enable future diagnostic validation and comparative studies in pathological populations.