John W. Whitting, Jonathan L.A. de Melker Worms, Christian Maurer, Sandro R. Nigg, Benno M. Nigg

Lateral shuffle and side cut (SSC) movements are defensive basketball movements where movement speed is critical to performance. The purpose of this study was to compare SSC data obtained using timing lights with motion capture system data and to determine the most appropriate method for measuring SSC performance. Shuffle time data were recorded using both timing lights and a motion capture system while 9 male subjects performed 2 different SSC movement sets, with and without controlling for arm movements, which may influence performance times. Shuffle and side cut times and SSC displacements were used to calculate mean shuffle velocity for each trial. The SEs for the motion capture system were estimated for SSC times (± 4.2 milliseconds; ~0.24% of mean shuffle time) and velocities (± 5.5 mm · s; ~0.24% of mean shuffle velocity), respectively, indicating high levels of precision. Timing light movement time variability was significantly higher during the uncontrolled (SD = 42 milliseconds) when compared with the controlled (SD = 9 milliseconds, p < 0.001) condition, indicating a significant reduction in variability by controlling non-performance-related variability such as arm movement. A significant positive correlation was found between SSC time and SSC displacement (r = 0.42) indicating that performance times were dependent on displacement. Furthermore, the variance in motion-captured SSC velocity was significantly smaller than the variance in velocity determined using timing lights (p < 0.05). We concluded that motion-captured SSC velocity data reduced systematic errors and non-performance-related movement variability and, therefore, was better able to reflect true performance. As true performance variability in human movement provides important information, the presented method for calculating SSC velocity in this study is recommended for assessing SSC performance.