Landing Technique Effects on Lower-Limb Biomechanics During Half-Squat Parachute Landing.

INTRODUCTION

During a half-squat parachute landing, foot-strike pattern influences joint kinematics and injury risk. This study compared forefoot and full-foot landing techniques to determine their effects on joint biomechanics, impact forces, and landing stability.

METHODS

A total of 17 male paratroopers performed both landing conditions. Lower-limb kinematics, ground reaction forces, and surface electromyography were synchronously recorded using infrared motion capture, a force platform, and wireless electromyography. Paired-sample t-tests or Wilcoxon signed-rank tests were applied (α = 0.05).

RESULTS

Forefoot landing produced greater knee (96.8 ± 12.2° vs. 89.3 ± 11.2°) and ankle range of motion (12.7 ± 3.8° vs. 10.8 ± 3.1°), higher peak knee (1206.4 ± 108.7 ° · s-1 vs. 1147.8 ± 88.8 ° · s-1) and ankle flexion angular velocity (223.5 ± 60.1 ° · s-1 vs. 156.5 ± 42.5 ° · s-1), and a longer braking phase (265.0 ± 29.4 ms vs. 246.5 ± 24.7 ms). It also reduced peak vertical ground reaction forces, loading rate, and dynamic postural stability index, and increased time to peak ground reaction forces. During preactivation, electromyography amplitudes were higher for the biceps femoris (0.097 ± 0.066 vs. 0.081 ± 0.071), lateral gastrocnemius (0.304 ± 0.251 vs. 0.130 ± 0.070), and medial gastrocnemius (0.203 ± 0.144 vs. 0.111 ± 0.105). During the braking phase, amplitudes were higher in the rectus femoris, biceps femoris, semitendinosus, lateral gastrocnemius, and medial gastrocnemius.

DISCUSSION: Forefoot landing enhances joint motion, muscle activation, impact attenuation, and dynamic stability during half-squat parachute landing. It may therefore represent a safer landing strategy. Findings should be interpreted cautiously due to the small, all-male sample. Ye Q, Chen H, Huang B, Wan X, Wang G. Landing technique effects on lower-limb biomechanics during half-squat parachute landing. Aerosp Med Hum Perform. 2026; 97(6):435-442.