A Three-Dimensional Dynamic Analysis of the Quarterback's Throwing Motion in American Football

Abstract

Twelve collegiate football quarterbacks were videotaped while performing drop back passes. The video images were digitized using a Peak Performance system, and three-dimensional (3-D) kinematic and kinetic data were calculated from the 3-D coordinate data using standard analytical procedures. The sequential timing of peak shoulder torques in the delivery for the football throw was peak abduction torque prior to the point of maximum shoulder external rotation (MER), peak internal rotation torque just after MER, and peak horizontal adduction torque just prior to release. As anticipated, large medial deviation torques at the elbow were found in the acceleration phase. However, in many cases the quarterbacks demonstrated larger elbow lateral deviation torques during the follow-through than found in the acceleration phase. This paper will describe these and other kinetic results and the kinematic findings observed during the football pass.