THE RELATIONSHIP BETWEEN KINEMATIC VARIABLES AND SHOOTING DISTANCE IN BASKETBALL: A RE-EVALUATION

Abstract

The majority of studies which consider the kinematics of basketball shooting have either analysed technique for shots from a single distance (e.g. Hudson, 1985), or have compared technique across two distances (e.g. Elliott and White, 1989). Whilst such methods allow comparison of kinematic variables at the distance(s) investigated, they do not permit conclusions to be drawn with respect to their relationships over a range of distances. This is because for a case in which there are only two levels of independent variable, the only possible interpretation of its relationship with dependent variables is linear. The objective of this study was, therefore, to investigate the relationship between various kinematic parameters and shooting distance using a wide range of distances. Three dimensional video techniques (50 Hz) were used to record basketball jump shots from a range of distances (0.9-8.5 m), as performed by members of the men's quarter-finalist teams at the XVI World University Games. Eighteen sequences were digitised from 20 frames prior to take-off to 10 frames after release. Shooting distances were established by comparison with court markings. The correlation between the square of release speed and shooting distance yielded a value of r = 0.90 (p < 0.01), which is consistent with theoretical predictions. The correlation between release speed and angular velocity of the elbow joint of the shooting arm at release (r = 0.75, p < 0.01) led to the expectation that the latter would approximate a quadratic relationship with shooting distance. This was found to be the case, especially for shooting distances greater than 3 m. Despite previous reports of no significant when using ANOVA on a three group design (Miller, 1993), a negative correlation (r = -0.68, p < 0.01) was found between shooting distance and angular displacement of the elbow of the shooting arm at release, suggesting a decrease in the latter as shooting distance increases. No relationship was found between release angle and shooting distance, despite previous reports to the contrary (Miller, 1992). This is likely to be due to the effects of differing release heights for different subjects in the current study. It was concluded that ascertaining the true nature of relationships between kinematic variables and distance can be problematic when using a small number of shooting distances, and that this method is recommended as providing increased information to coaches and teachers with respect to the required modifications to the kinematics of shooting at different distances from the hoop.