Flexural vibration and the perception of sting in hand-held sports implements

In the sports of baseball, softball, and field hockey a player swings a bat or stick held in both hands to hit a relatively hard ball. Poorly hit impacts often result in painful sting in one or both hands. Experimental modal analysis is used to reveal the flexural mode shapes contributing to sting. This paper compares the flexural mode shapes responsible for causing sting in each sport, highlighting differences in hand positions between sports. Two-piece construction, material selection, and vibration absorbers have been used to reduce sting in metal and composite baseball and softball bats and in composite field hockey sticks. Damping rates for various bat and stick compositions will be compared. Recent success in the reduction of sting in bats and sticks using vibration absorbers will be discussed.