# Movement efficiency in taekwondo side kick (Yop Chagi): a kinematic comparison between novice and experienced practitioners

## TL;DR

This study compares how experienced and novice taekwondo practitioners perform a side kick, finding that experienced ones are more efficient in their movements.

## Contribution

The study reveals specific kinematic differences in Yop Chagi execution between novice and experienced taekwondo practitioners, highlighting movement efficiency gains from training.

## Key findings

- Experienced practitioners showed significantly larger hip abduction and knee flexion angles during the chamber phase.
- The experienced group had a 28% higher peak linear velocity of the foot and shorter total kick execution time.
- Long-term training optimizes the proximal-to-distal kinematic sequence, enhancing kick performance.

## Abstract

This study aimed to kinematically compare the Yop Chagi execution between novice and experienced university Taekwondo practitioners, focusing on movement efficiency.

Forty university students were allocated into two groups: Novice (n = 20; ≤6 months experience) and Experienced (n = 20; ≥3 years of competitive experience). Participants performed maximal effort side kicks targeting a pad at trochanter height. Movement was captured using two high-speed cameras (120 Hz). Kinematic variables included hip and knee joint angles at peak flexion/extension, peak angular velocities, linear velocity of the foot, and total kick execution time. Between-group differences were analysed using independent t-tests or Mann-Whitney U tests, with effect sizes (Cohen’s d) reported.

The experienced group demonstrated significantly larger hip abduction and knee flexion angles during the chamber phase (p < 0.01, d > 0.8), and greater knee extension at the point of impact (p < 0.01, d = 1.2) compared to novices. The experienced group also exhibited superior performance in peak hip and knee angular velocities (p < 0.01, d > 1.5), resulting in a 28% higher peak linear velocity of the foot (p < 0.001, d = 2.1). Furthermore, the total execution time was significantly shorter for the experienced group (p < 0.01, d = 1.4).

Experienced practitioners execute the Yop Chagi with a more efficient kinematic pattern, characterized by a larger range of motion, faster segmental velocities, and reduced execution time. These findings suggest that long-term training optimizes the proximal-to-distal kinematic sequence, enhancing kick performance.