The effects of pressure on anticipatory postural adjustments during a jump shot in basketball

Abstract

BackgroundAnticipatory postural adjustments (APAs) play an important role in feedforward control of dynamic movement, such as jump shot performance in basketball. It is known that jump shot performance declines under pressure from a defender (shot blocker). Research questionDoes pressure from a shot blocker affect APAs of a jump shot in basketball? Is jump shot performance in basketball associated with APAs? MethodsFourteen healthy male university basketball players performed jump shots under pressure and non-pressure (free) conditions by a shot blocker. Using a force plate, the APAs were defined as occurring until the point of thrust (TH) phase, and ground reaction force (GRF) and center of pressure (COP) at that moment were assessed. To assess jump shot performance, the maximum GRF during the TH phase (THmax), jumping height, and success score of the shot (accuracy score: AS) were measured by using the vertical component of the force plate. Two-way ANOVA examined the effects of the phase and condition on APA duration. Pairwise t-tests analyzed pressure effects on subjective pressure intensity, AS, and kinetics measures. Relationships between condition changes in AS and COP or GRF variables were assessed via Pearson correlations. Differences between the pressure and free conditions were denoted by {Delta}. ResultsThe APA duration was shorter under the pressure condition compared to the free condition. The THmax and jump height values were greater under the pressure condition relative to the free condition. Across conditions, changes in COP variables were significantly and negatively correlated with AS. SignificanceThe results of this study suggest that pressure from a shot blocker shortens APA duration and decreases jump shot performance. Additionally, by measuring players APAs and evaluating relationships with jump shooting proficiency, APA variables could potentially serve as indicators of skill expertise.