Different Executions of high turning kick in martial arts

At moment studies in martial art have been allowed in many different fields: energetic, cognitive, but few have been focused in technique. Moreover those studies analysed the effect of the hit and not his mechanical cause. Abraham C. et all. 2001 studied the e.m.g activity in three different kicks of martial art but without cinematic. Soresen H. et all. 1996 analysed the front kick to understand whether the extension of knee was due to the inertia force or to the thigh muscular action. Chwala W. et all. 2004, analysed different kicks technique with 3D device (Vicon) and force plate. Anyway this study focused on the forces of supporting leg on the ground and not about the technical execution. There are several kicks in martial arts but turning kick is common and similar in each of them. Turning kick (also known as a round kick or roundhouse kick) is a kick in which the attacker swings his leg around in a semicircular motion, striking with the front of the shin or the foot. This type of kick has many variations based on stance, leg movement, striking surface, and the height of the kick. Wikipedia (7), one of the most popular encyclopaedias shows instead three similar methods of turning kick: thai-boxe named “Hi kick”, taekwondo “Dollyo-chagi” and karate “Mawashi-geri jo-dan”. Than this technique has been studied previously only with e.m.g. approach (1) or only with 3D (2), but never both combined. Aims The aim of this study was to evaluate the cinematic of kicking leg and its muscular activity, during high turning kick performed by different subjects from different martial arts as proposed by (7) in order to underline the differences and the similar. We focus in joint timing and in muscular activity of rectus femoris, biceps femoris and gluteus medialis of kicking leg. Those muscles have been chose as majors responsible of the assessed joint actions. Methods Three expert fighters (5/8 yrs. of experience) practicing different martial arts: thai-boxe (THA), taekwondo (TKW) and traditional karate (KAR), were the subjects of this study. THA was 25 yrs., 178 cm tall, 73 Kg weight; TKW was 27 yrs., 186 cm tall, 80 Kg weight; KAR was 21 yrs., 173 cm tall, 77 Kg weight. After 10 minutes of warm-up each subject performing a mobility specific test to evaluate the max abduction of the hips. Afterward the participants completed three repetitions of high turning kick at maximum performance to a specific target with their dominant leg (right for everybody). Cinematic analysis was allowed by Vicon system (6 cameras 460 IR led registration -100Hz) connected to Noraxon Telemyo 2400 Emg system (1000Hz). 38 reflective markers have been set on the skin of the subjects following the “total body model”. Three goniograms were analysed:  hip flexion (FXH)-extension (EXH),  hip abduction (ABH)-adduction (ADH),  and knee flexion (FXK)-extension (EXK). The skin was shaved, rubbed and cleaned with alcohol. Bipolar Ag/AgCl surface electrodes (10 mm of diameter) were placed on the muscle bellies with a centre distance of 30 mm and parallel to the muscle fibres, following the S.e.n.i.a.m. (6) advice. Raw signal has been filtered with band-pass (20-500 Hz), rectified, and processed using a root mean square (RMS) algorithm. For each muscle we allocated the onset and the offset following the standard deviation method proposed by Jöllenbeck T. (3). The SPSS package has been used for descriptive and inferential statistic analysis (Kruskal-Wallis parametric test). Cinematic results Cinematic analysis of some markers showed several important events (table 1), the height of the hit, the rise time of the kick, the slope time, and the total time considered between the take-off of the foot and his further landing. Those data didn’t show differences in rise time. Instead other variables showed differences. TKW showed slope and total time longer than in other subjects. TKW and THA showed a flight phase. For each tria..