3-dimensional kinematics of overarm throwing action of children age 15 to 30 months.

7 children 15 to 30 mo. old participated in a study of 3-dimensional kinematics of overarm throwing. Children of different ages were considered to be at different developmental stages of motor development. Video recordings were digitised and 3-dimensional coordinates established using the DLT algorithm. Qualitative analysis indicated that the children executed either a 'static' or 'dynamic' throwing action. Either could further be classified as 'arm dominated' or 'sequentially linked.' Maximum elbow extension was no more than 163 degrees for any child; release velocity was higher for older subjects; and the angle of ball release was large in 'arm-dominated throws' (M = 49 degrees) and comparatively smaller in 'sequentially linked' throws (M = 15 degrees).