Flexibility and leg muscle power as correlates of dollyo chagi kicking performance in junior taekwondo athletes

Abstract

Research Problem: Dollyo chagi (roundhouse kick) performance requires coordinated lower-limb movement, sufficient mobility, and rapid force production. However, the extent to which general flexibility and leg muscle power are associated with timed, accuracy-based kicking performance among junior Taekwondo athletes remains unclear. Research Objective: This study examined the individual and combined associations of flexibility and leg muscle power with dollyo chagi performance in junior Taekwondo athletes. Methods: A cross-sectional correlational study involved 30 athletes (16 males and 14 females) from one Taekwondo club, selected using saturated sampling. Flexibility was assessed using the sit-and-reach test, leg muscle power using a wall-based vertical-jump test and kicking performance using the number of accurate dollyo chagi kicks completed in 15 seconds. Pearson correlations and sex-stratified multiple linear regression analyses were conducted. Results: Among males, flexibility was not significantly correlated with kicking performance (r = .372, p = .155), whereas leg muscle power was positively correlated with performance (r = .731, p = .001). Among females, flexibility (r = .680, p = .007) and leg muscle power (r = .717, p = .004) were both positively correlated with performance. In the multiple regression models, leg muscle power remained independently associated with performance among males (B = 0.370, β = .779, p = .005) and females (B = 0.401, β = .503, p = .032). Flexibility was not independently associated with performance in either group (males: p = .728; females: p = .061). The models explained 53.8% and 65.3% of the variance in male and female performance, respectively. Conclusion: Leg muscle power showed a consistent positive association with timed dollyo chagi performance in both groups. The association involving flexibility was less consistent and was not statistically significant after adjustment for leg muscle power. These findings are preliminary and should be interpreted considering the small, single-club sample and the use of general field-based tests.