Basketball layup: Foot loading characteristics and the number of trials necessary to obtain stable plantar pressure variables

Abstract

This study aimed (1) to profile the plantar loading characteristics when performing the basketball layup in a realistic setting, and (2) to determine the number of trials necessary to establish a stable mean for plantar loading variables during the layup. Thirteen university male basketball players [age: 23.0 (1.4) years, height: 1.75 (0.05) m, mass: 68.4 (8.6) kg] performed ten successful basketball layups from a stationary position. Plantar loading variables were recorded using the Novel Pedar-X in-shoe system. Loading variables including peak force, peak pressure, and pressure time integral were extracted from eight foot regions. Performance stability of plantar loading variables during the takeoff and landing steps were assessed using the sequential averaging technique and intra-class correlation coefficient (ICC). High plantar loadings were experienced at the heel during the takeoff steps, and both the heel and forefoot regions upon landing. The sequential estimation technique revealed a five to eight trial range to achieve a stable mean across all plantar loading variables whereas ICC analysis was insensitive to inter-trial differences of repeated layup performances. Future studies and performance evaluation protocols on plantar loading during basketball layups should include at least eight trials to ensure that the measurements obtained are sufficiently stable.