Chosen aspects of physics in martial arts Jacek Wąsik Department of Surface Physics, Jan Dlugosz University of Czestochowa, Poland Source of support: “Young Researcher 39 ½” Grant funded by the Archives of Budo Received: 13 January 2009; Accepted: 31 January 2009; Published online: 6 February 2009 Abstract Background: 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/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 measur- ing 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 going beyond 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 in- creases 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. Key words: taekwon-do • power test • ap joomuk jirugi • time of reaction • harm energy Author’s address: Jacek Wąsik, Institute of Physics, Jan Długosz University, Armii Krajowej 13/15, 42-200 Częstochowa, Poland, e-mail: jwasik@konto.pl BACKGROUND 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 ob- tain different energies. That is why practicing martial arts, punches, kicks, jumps or doing other exercises to achieve strength follow the same rules. The sight of a person breaking a pile of boards or an- other hard object with his or her bare hand or foot can be associated with special or supernatural skills and predispositions. One of the characteristic features for Taekwon-do is its Theory of Power [1–3], which con- sists of the following factors: mass, acceleration, equi- librium, concentration and breath control. The first two factors are typically physical values but the others may also be described in physical categories. Equilibrium is connected with placing correctly the centre of grav- ity of a person. Concentration is, in other words, the focus of a punch. This association with optics is justi- fied due to the resemblance between the focus of light and the focus of the force during performing a punch. Taekwon-do – a Korean martial art based mainly on punches and kicks. VOLUME 5 | 2009 | 11 © ARCHIVES OF BUDO  ORIGINAL ARTICLE Authors’ Contribution: A Study Design B Data Collection C Statistical Analysis D Manuscript Preparation E Funds Collection - - - - -