Relationship between sensory evaluation in grasping of baseball bat grip and finger pressure exerted to the bat grip

Abstract

This study investigated the characteristics of grip diameter of baseball bat by subjective evaluation on easiness of grasping and grasping pressure at both hands during bat swing movement. For six baseball players, the easiness of grasping bat grip were measured by subjective evaluation table of seven phases (+3 ; very very easiness ~ -3 ; very very difficult). The grasping pressure on bat grip were measured by strain gage sensor put on sixteen parts on both hand, and the fluctuation of the bat at the ball impact phase were measured by acceleration sensor for three direction put on top of the bat. The used bat in these experiment produced by preliminary measurement if the bat grip size that was the baseball players used in daily practice. The optimum diameter of bat grip was similarly to the diameter used in daily practice. In the characteristics of the grasping pressure during bat swing phase, the integrated grasping pressure exerted the hands showed the high value especially at the middle, ring and little finger. The integrated grasping pressure in the optimum diameter of bat grip showed the tendency the high value compared with another diameter of bat grip. But, in the ball impact phase, the integrated grasping pressure in the optimum diameter of the bat grip showed the lower value.