Kinetics and Kinematics of the Overhand, Hybrid and Sidearm Shot of Lacrosse

Lacrosse, Canada's national summer sport, is a sport anchored in first nations' tradition. Its growing popularity in North America has not been reflected by a similar interest in the scientific literature more specifically on the biomechanics of the lumbar spine with its throwing motion. The aim of this study was to describe the motions, forces and muscle actions of the lumbar spine with the hybrid, overhand and sidearm throw. Twelve subjects were asked to throw at maximal speed while captured by a 3D motion analysis system. Flexion, extension and axial rotation angular velocities as well as positive and negative powers in the two planes were calculated. The first research question pertained to consistency in angular velocities and powers between trials of a given throwing technique. Subjects showed a fairly high variation on all variables but mostly with the angular velocities in extension and the peak positive power in flexion/extension which had high coefficient of variations (CVs). The contralateral rotation velocity and the positive rotation power had the lowest CVs. Overall the CVs for powers exceeded the angular velocities'. The second research question addressed if a difference in variables was present between the three throwing methods. A significant difference was observed in the peak negative power in flexion/extension and the peak positive power in rotation. The contralateral rotation angular velocity also showed a significant difference but the sphericity assumption failed. No other variable showed a significant difference but the observed power for those variables was also quite small. Due to the lack of power and the further need for controlling some unforeseen sources of error, this study can be used as a pilot study to further define and improve future studies in the field of lacrosse biomechanics.