Modeling the Lacrosse Stick as a Rigid Body Underestimates Shot Ball Speeds

Abstract

In the last decade, dramatic changes in lacrosse stick design are believed to be associated with changes in the play of the game; however, there is a limited understanding of how the lacrosse stick propels the ball. We predicted that the lacrosse stick would perform as a passive extension of the player’s hand and hypothesized that ball shot speed would be equal to the speed at the tip of the stick. Ball and shot kinematics of 16 male and 16 female lacrosse players using four various stick models were tracked at 250 Hz. The speed of the ball was compared with the speed at the tip of the stick, calculated by assuming the stick behaved as a rigid body. Ball shot speeds with men’s sticks were on average 3.5 m/s (7.8 mph) faster than the calculated speed at the stick tip, and ball shot speeds with women’s sticks were on average 0.7 m/s (1.5 mph) faster than stick tip speed. Some lacrosse stick models can shoot the ball significantly faster than predicted when considering the stick as a rigid, passive extension of the player’s hands.