Examining Control Parameters in Over Arm Throwing

The purpose of this study was to examine if trunk linear and angular velocities and throwing arm preparatory positional configurations are control parameters overarm throwing development (Stodden et al., 2006). Data was collected from 30 participants (16 males and 14 females; average age = 21.4 years) who agreed to participate in this study. Participants threw tennis balls at a target at seven different distances of 15, 25, 35, 45, 55, 65 feet and maximum effort, in progression, to simulate throwing developmental trajectories. Each progressive target distance demanded an increase in systemic energy output to be able to complete the task of hitting the target. Each participant was marked with retro reflective 1cm diameter markers on the major joints of the body. Marker reflections were tracked individually by 6 synchronized 200 Hz  cameras (Vicon. Inc, Los Angeles, CA).  3D kinematic variables including hip and upper torso angular and linear velocities, throwing shoulder abduction and elbow flexion will be processed by Visual 3D software (Germantown, MD). Repeated measures ANOVAs  and appropriate post hoc tests will determine if there are significant differences in the proposed kinematic variables across distance thrown. As proposed by Stodden et al., 2006 we intend to examine if the increases in system energy demanded by the task results in significant changes in trunk, linear, and rotational velocities and arm preparatory positional configuration. Results of the study will delineate developmental trends in overarm throwing and will provide insights into the mechanisms underlying the development of skilled throwing