Trunk and lower limb muscle activation in linear, circular and spin back kicks

Abstract

Background and Study Aim: As any martial art, taekwondo can be classified as a specialty that requires high technical skills, such as a fine motor control both in static and dynamic conditions. Practitioners predominantly use kicks with high amplitude in both combat and technique (poomse) modalities. The aim of this study was the knowledge about trunk and lower limb muscle activation according to the type of kick (circular, linear and spin back kick) in the taekwondo technique modality. Material and Methods: Twelve healthy and elite male taekwondo athletes voluntarily participated in this study. Surface electromyography (EMG) during maximal isometric voluntary contractions (MVC) and execution of the kicks was bilaterally recorded from rectus abdominis (RA), external and internal oblique (EO and IO), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius lateralis (GL), in the static phase of the three kicks. Results: The results of this study (in terms of MVC percentages) showed a main effect of the type of kick (p < 0.05); that is, during the static phase of the kick muscle activity changed based on the type of kick. In the kicking leg, trunk and hip flexor and knee extensor muscle activation (mainly RF, IO and RA) was higher in linear kicks than in circular and spin back kicks. GL and RF activation levels were higher in circular kicks than in spin back kicks. In addition, the higher levels of ES activation were found in the spin back kicks. Regarding the supporting leg, no differences between kicks were found for TA and GL, which were possibly activated to ensure ankle stability during the single-leg stance. Conclusion: These findings may allow researchers and taekwondo coaches to design training programs appropriately.