Inter-Limb Differences in Impact Force and Segmental Accelerations at the Instant of Peak Force During the ITF Taekwon-Do Turning Kick

Inter-limb differences in kicking performance are often evaluated using force and independently identified peak kinematic variables that may occur at different phases of the movement. This study examined impact force, effective mass, and segmental accelerations at the instant of maximum force during the ITF taekwon-do turning kick. Sixteen adult male black-belt practitioners with at least 10 years of training experience performed maximal-effort kicks with both legs. Impact force was measured using a force platform, while thigh, shank, and foot accelerations were recorded using triaxial accelerometers synchronized with the force platform. Inter-limb differences and associations with maximum impact force were analyzed using non-parametric methods with false discovery rate correction. All participants reported the right leg as their preferred kicking leg based on habitual kicking preference. The right leg generated greater maximum impact force than the left leg (2268.10 vs. 1561.20 N; pFDR = 0.0077) and showed greater foot (pFDR = 0.0077) and shank (pFDR = 0.0077) accelerations at maximum force. For the right leg, impact force was associated with foot acceleration (ρ = 0.692, pFDR = 0.048). The association between inter-limb differences in force and thigh acceleration did not remain significant after FDR correction (ρ = 0.577, pFDR = 0.078) and was considered exploratory. Inter-limb differences in turning-kick performance were evident in impact force and distal-segment accelerations at the instant of peak force. Time-matched bilateral analysis may provide a more specific characterization of segmental dynamics associated with impact force. These findings should be interpreted in the context of the uniform right-leg kicking preference of the sample.