Background & Study Aim: The punch is a key component of boxing. In scientific papers, there is information about kinematic indicators and impact forces. It mentioned that lower extremity has a strong effect on impact force, through transferring momentum into the kinetic chain system. However, the differences of impact forces in different boxing posture have not been fully investigated. The aim of the study was the effects of impact forces and some kinematic indicators in boxing both orthodox and southpaw stance of straight punch technique.