摘要：Background and Study Aim: All activities performed by a human being depend on physical phenomena. A human body is a biomechanism which is affected by different forces. The body as well as its parts can move with various velocities and can obtain different energies. That is why practicing martial arts, punches, kicks, jumps or doing other exercises to achieve strength follow the same rules. Material and Metods: The aim of the research was to analyse a simple punch forward (in the Taekwon-do terminology: Ap Joomuk Jirugi). Research on kinematics and kinetics of some chosen movements in Taekwon-do ITF was made with the BTS Smart Morion Capture system used for three dimensional movement analysis. A 17-year-old competitor measuring 175 cm and weighing 70 kg was analysed in the laboratory of Motoric Diagnostics in the Academy of Physical Education of Katowice. Results: Up to 20% of the cycle the fist speed is a little higher than 0. Between 20–50% have negative speed. After goingbeyond 50%, the speed is rapidly rising to reach the maximum power of 86%. The maximum speed 6.184±0.534 m/s. Afterwards rapid decrease in speed is observed. Conclusions: Minimal theoretical time of a person’s reaction to an attack is about 0.2 sec and practically it is 0.4 sec. The time for the punch to reach its goal is 0.1 sec. This fact can suggest that it is not possible to defend against a punch. On the other hand we know that people can defend themselves against an attack. Apparently it appears that it is not worth doing anything because we have no chances, but it is an argument to practice martial arts and self-defence. The trainings give a person faith in his or her own strength, they teach how to recognize the opponent’s abilities, how to stand to decrease the body part susceptible to attack and how to make the distance longer (which also increases the time of a potential attack). They also teach how to concentrate the attention and energy as well as how to predict the opponent’s movement and how to surprise him or her
关键词：ap joomuk jirugi; physic in martial arts; taekwon-do
