Effect of Rosin Powder on Friction between Finger Pad and Baseball

Abstract

The control of slippage between a hand and an object is fundamental to improving athletic performance in sports that require a strong grip, such as baseball and rock-climbing. In order to prevent slippage between a hand and an object, athletes often use grip-enhancing powders to maintain grip in both dry and wet conditions. In baseball pitching, rosin powder, which comprises magnesium carbonate powder and pine resin, is often used as grip-enhancing agent. In this review, the normal force range applied at the finger during ball releasing process in fastball pitching is introduced and the effect of rosin powder application at the finger tip on the frictional characteristics between finger and baseball leather sheet is described. The friction coefficient is not necessarily increased by the presence of rosin powder at the finger pad-leather sheet interface under dry conditions. However, under wet conditions, rosin powder application increases the friction coefficient relative to the nonpowdered condition in the large normal force condition, indicating the efficacy of rosin powder as a grip-enhancing agent.