Biomechanical analysis of countermovement jump performance before and after long-distance run with arch support footwear.

backgroundLong-distance running induces acute lower-limb fatigue, and arch-support footwear is widely used to modulate foot mechanics; however, how arch-support height interacts with running-induced fatigue to affect countermovement jump (CMJ) take-off biomechanics remains unclear. PURPOSE: To investigate the effect of acute fatigue from half-marathon and arch support heights on countermovement jump (CMJ) biomechanics, and to elucidate the potential mechanism.

methodsTwenty-one male recreational runners completed countermovement jump (CMJ) tests before and after a half-marathon under two footwear conditions: low arch support (AS-5 mm) and high arch support (AS-20 mm), representing minimal versus pronounced midfoot support. Before testing, foot arch type was screened with the ink-footprint method and the Arch Index (AI; Cavanagh and Rodgers, 1987); all participants had normal arches (0.21 ≤ AI ≤ 0.26, 0.24 ± 0.02). Three-dimensional kinematics and ground reaction forces were captured using a Vicon motion-capture system and Kistler force plates, and lower-limb joint angles and net joint moments (hip, knee, ankle) were computed in OpenSim. Outcome measures were hip, knee and ankle joint angles and net moments, and jump height. Joint waveforms were time-normalized to 0-100% of the CMJ take-off cycle (from movement onset to toe-off). Jump height was analyzed with two-way repeated-measures ANOVA (factors: arch support and fatigue); joint waveforms were analyzed with two-way repeated-measures ANOVA in SPM1d to test the main effects of arch support and fatigue and their interaction.

resultsRegarding arch support, hip flexion angle in AS-5 mm was significantly greater than AS-20 mm during 0-100%, knee flexion angle during 0-99%, and ankle dorsiflexion angle during 0-23% (p < 0.01), with jump height in AS-5 mm approximately 20.5% greater than AS-20 mm (p < 0.001). Regarding fatigue, post-fatigue hip internal rotation angle increased significantly during 0-79% and 81-100% (p < 0.01), knee flexion angle increased during 32-58% (p < 0.01), and knee adduction angle increased (p < 0.01). Regarding interaction effect, under AS-5 mm condition, post-fatigue hip internal rotation angle increased significantly during 0-100%, and knee abduction angle decreased significantly during 0-32% and 87-100% (p < 0.01), whereas changes in AS-20 mm were relatively minor, indicating that high arch support effectively mitigates the negative effects of fatigue on lower limb joint stability.

conclusionsLow arch-support shoes were associated with greater lower-limb joint range of motion and an approximately 20.5% greater jump height than high arch-support shoes. Acute fatigue reduces neuromuscular control by increasing hip internal rotation and altering knee joint kinematics. High arch support shoes maintain foot stability and reduce compensatory movements of proximal joints through kinematic chain transmission, which may help maintain proximal-joint kinematic stability under fatigue.