FINGER FORCES DURING BASEBALL PITCHING

Abstract

A 3D force transducer was installed in an official baseball to make a direct measurement of finger force imparting on the ball during pitching. Eight collegiate pitchers threw a 4- seam fastball at their maximal speed. Force was measured separately from each of the index, middle, and ring fingers, and the thumb. Peaks and peak occurrence time of computed resultant and shear forces were evaluated. Index and middle finger forces generally had a bimodal pattern with the first and second peaks appeared at about 80, and 96% of the stride foot contact period, respectively. Their force magnitude reached 90 N. and above. Magnitude of shear force was about half of the resultant force. Forces by the thumb and ring finger were less than those by the index and middle fingers. The findings indicated that the fingers were applying considerably large magnitude of force during pitching.