KINETIC ANALYSIS OF BENCH STEPPING: WHAT ARE THE EFFECTS OF BENCH HEIGHT AND MUSIC TEMPO?

Abstract

440 The purpose of this research was to determine if variations in bench height and music tempo affect kinetic parameters in the step-down phase of bench step aerobics. Twenty experienced females (26.95 years) volunteered to participate. Each subject performed 27 randomly ordered trials containing combinations of the three bench heights (6, 8, 10 inches) and three music tempos (120, 130, 140 beats per minute). Data were collected with an AMTI force platform. Data were sampled at 500HZ and recorded for two seconds to capture the step-down phase of the motion. A 3×3 factorial MANOVA (alpha of 0.05) design was used to evaluate the kinetic data with bench height and music tempo as independent variables and vertical, mediolateral and anteroposterior kinetic parameters as the dependent variables. Significant differences were found between all bench heights for peak vertical forces (p=0.000), peak vertical impulse (p=0.007), time-to-peak vertical force (p=0.000), and time-to-peak anteroposterior force (p=0.000). Significant differences were found between all music tempos for peak vertical impulse (p=0.008), time-to-peak vertical force (p=0.000), and time-to-peak anteroposterior force (p=0.018). The kinetic trends reflected greater magnitudes as bench height and music tempo increased while time-to-peak kinetic parameters decreased. It was concluded that the potential for musculoskeletal injury due to repetitive bouts of bench stepping activity may increase as bench height and music tempo increase.