Relationship between hammer throw performance and hammer head velocity

Abstract

A study was conducted to clarify the relationship between hammer throw performance and hammer head velocity during four-turn throwing. Hammer head movements of 26 male hammer throwers including from world's top-ranking athlete down to unskilled level performing the four-turn throwing method were filmed at 60 fps using two video cameras at five athletic competitions. The hammer head was digitized and the three-dimensional coordinates were calculated using the DLT method. The results revealed a significant positive correlation between throw distance and the initial velocity of the hammer head (r=0.917, P<0.001). However there were no significant correlations between throw distance and the release angle of the hammer head, or between throw distance and the release height of the hammer head. The velocity of the hammer head increased with the number of turns, and the maximum velocity of the hammer head at each turn showed a significant positive correlation with the throw distance. The radius of curvature of the hammer path was calculated from the velocity and acceleration of the hammer head. The hammer head showed greater tangential acceleration when the radius of curvature of the hammer path was reduced. Furthermore, the normal acceleration increased during the phase when the radius of curvature of the hammer path was reduced.