Abstract
It is important for football players to efficently transfer mechanical energy generated by a whole-body kicking motion to a ball. The objectives of this study were (1) to quantify how much energy is transferred to the ball from the body during a football kick (energy transmission efficiency), and (2) to compare the energy transmission efficiency between experienced and non-experienced football players. 6 experienced and 6 non-experienced football players performed 3 types of kicks at 3 different intensities. Whole-body kinematic data were obtained by a motion capture system and ball speed was measured by a high speed camera. Mechanical energy of the whole body-during the kick and that of the ball after impact were calculated. The energy transmission efficiency was then defined as a percentage of the mechanical energy of the ball relative to the whole body. The energy transmission efficiency was found to be about 30% at a maximum, and the experienced subjects exhibited a higher energy transmission efficiency as compared to the non-experienced subjects. This suggests that energy transmission efficiency would be associated with football kicking skills, which could allow us to grade individual players at different levels in kicking technique.
