The relation of kinematic factors to the acquisition of skill on a novel task.

The purpose of the study was to determine which kinematic factors changes and how they changed during the process of skill acquisition. A novel throwing task, involving only the elbow joint, was selected that could be learned during one session. Biomechanical data were collected on-line by a program in a PDP - 11/34 computer via an A to D converter. Angular displacement, linear acceleration, and instant of ball release were continuously monitored and velocity was calculated. The subjects acquired the task within the first ten out of forty learning trials. Consequently, group analyses were limited to the first ten throws. The mechanical factors showed changes with skill acquisition, with elbow angle and elbow velocity at release accounting for 99% of the variance in score. It was found that to obtain the desired performance outcome, each subject selected his own limited range of angles and velocities at release. Although pertinent biomechanical factors are task specific, individuals in this case selected their own strategies to get the same outcome on a task.