The repeatability of choku-tsuki and oi-tsuki in traditional shotokan karate: A morphological three-dimensional analysis

The aim of the study was to quantify the repeatability of the displacement of selected body landmarks while performing two different basic karate atta cks. Seven karateka (three men, four women) with different levels of traini ng and knowledge of karate were filmed with an optoelectronic computerized instrument (sampling rate 100 Hz) that allows the three-dimensional reconst ruction of the movements of selected body landmarks. Thirteen landmarks (he ad, hips, upper and lower limbs) were analyzed while performing 10 repetiti ons each of choku-tsuki (straight punch) and oi-tsuki (lunge punch). For ea ch karateka and punch, the average time of execution was calculated, and th e standard deviations of each of the three spatial coordinates x, y, z were computed for each landmark. A total standard deviation of the single karat eka and punch was also calculated For all karateka, the execution of oi-tsu ki took longer than the execution of choku-tsuki. For both punches and almo st all landmarks, the largest repeatability (smallest standard deviation) w as found in the vertical direction, while the smallest was found in the ant eroposterior direction (direction of movement). In all karateka, oi-tsuki h ad a total standard deviation about 3 to 6 times larger than that measured during the performance of choku-tsuki. On average, women had a larger repea tability than men. The method employed in the current study allowed the qua ntitative analysis of the repeatability of two basic attacks in Shotokan ka rate by using a landmark-based approach. The method could offer valuable he lp to karateka during training indicating which parts of the body do not re peat a selected movement with sufficient accuracy, thus assisting in the ac hievement of the most correct body form.