Sponge Mats, but not Taekwondo Mats, Reduce Landing Impact From Heights of 0.45, 0.90, and 1.35 m in Taekwondo Gyeokpa Players.

Abstract

Context: This study compared landing impact between 3 landing heights on 3 landing surfaces by quantifying vertical ground reaction force (vGRF) profile and knee joint angle.

Design: Crossover.

Methods: Nineteen healthy male college Taekwondo (TKD) Gyeokpa players (age: 20.7 [2.6] y, height: 1.73 [0.05] m, mass: 65.5 [7.1] kg, and athletic careers: 5.9 [3.2] y) performed 2-leg landings from 3 different heights (0.45, 0.90, and 1.35 m) on 3 different surfaces (uncovered force plates on the ground, a 2-cm thick TKD or a 14-cm thick sponge mat over the force plates). Peak vGRF, time to peak vGRF, and knee joint angle in the dominant leg were analyzed using analysis of variance and functional data analysis (α = .05).

Results: There was a height by surface interaction in peak vGRF (F4,144 = 2.54, P = .04) and time to peak vGRF (F4,144 = 7.62, P < .0001), but not for knee joint angle (F4,144 = 0.51, P = .73). Increased peak vGRF and shortened time to peak vGRF were observed as landing height increased on each landing surface (P < .0001 for all tests). Functional data analysis revealed that landing on the TKD mat increased vGRF by 0.4× body weight (P < .0001) at a landing height of 0.90 m or higher, whereas landing on the sponge mat reduced vGRF (<0.9× body weight), delayed time to reach peak vGRF (<30 ms, P < .0001), and maintained knee flexion angle (<10.3°, P < .01), compared with landing on the ground.

Conclusions: The TKD mat was ineffective in reducing the landing impact as similar landing biomechanics were observed between landing on the ground and the TKD mat. We recommend the use of the sponge mat to reduce landing impact as it attenuated vGRF, delayed time to reach peak vGRF, and maintained sagittal plane landing posture, as compared with landing on the ground and the TKD mat.