Expertise and distance as constraints on coordination stability during a discrete multi-articular action

The purpose of this study was to identify how coordination variability of the shooting arm varied as a function of interacting task constraints of expertise and shooting distance. Skilled, intermediate and novice male basketball players (n=9 in each group) performed 30 shots from three distances (4.25, 5.25 and 6.25 metres). The dependent variables included shooting performance scores and measures of coordination variability in three joint couplings: wrist-elbow, elbow-shoulder and wrist-shoulder. A main effect for distance was observed for shooting performance, with a reduction in score occurring with increasing distance. Significant main effects for expertise were also apparent for shooting performance together with coordination variability for all three joint couplings. Regression analyses revealed significant, negative relationships between shooting performance and coordination variability for all three joint couplings irrespective of shooting distance. The findings corroborated extant data on changes in movement variability with practice, demonstrating how skilled performers assemble stable movement solutions to satisfy changing task constraints, in contrast to novices and intermediates