Predicting children's overarm throw ball velocities from their developmental levels in throwing.

This study examined the movement process-product relationship from a developmental perspective. The authors used multiple regression to investigate the changing relationship between qualitative movement descriptions of the overarm throw and the throwing outcome, horizontal ball velocity. Seventeen girls and 22 boys were filmed longitudinally at ages 6, 7, 8, and 13 years. Their movements were assessed using Roberton's (Roberton & Halverson, 1984) developmental sequences for action of the humerus, forearm, trunk, stepping, and stride length. The sequences accounted for 69-85% (adjusted) of the total velocity variance each year. The components that best predicted ball velocity changed over time, although humerus or forearm action always accounted for considerable variance. Gender was a good predictor of ball velocity, but if the developmental descriptions were entered first in a stepwise regression, gender then explained no more than 2% additional variance.