The effect of ball size and basket height on the mechanics of the basketball free throw as performed by seventh grade boys

Abstract

The purpose of this study was to analyze the mechanics of the basketball free throw as performed by 13 seventh grade boys. A regulation and an intermediate sized basketball in combination with a 10-foot and an 8-foot basket were used. Two LoCam cameras, each operating at a film transport speed of 100 fps, provided simultaneous, non-synchronous sagittal and frontal views of repeated trials. Two successful trials per subject under each of the four environmental conditions were digitized with a Numonics digitizer interfaced to an Apple II+ microcomputer. The statistical analysis revealed significant differences (p = .05) for the main effect of basket height and non-significant differences (p > .05) for the main effect of ball size for the following kinematic parameters: (a) the angle of projection of the basketball, (b) the release angle of the shoulder, (c) the starting angle of the elbow, and (d) the forearm in relation to the vertical at ball release. Significant interaction effects (p = .05) between ball size, basket height, and the individual subjects were also revealed for some of the aforementioned kinematic parameters