| Organisms, including humans, react physiologically to environmental threats to avoid injury or death. A burst of broadband noise has been used as a stimulus with humans to mimic the response displayed in a threatening situation. Generating a defensive response via acoustic stimulation could lead to increases in muscular performance, based on known physiological reactions. The vertical jump test is the principal field test to determine power in the legs. The aim of this study was to characterize the effect of a burst of noise on subsequent jumping performance. Sixty untrained men and 60 untrained women were allocated to one of three jumping conditions (3, 8, or 15-seconds post-acoustic stimulation). Subjects were positioned on a force plate with a speaker located 0.3 m from their face. A 100 dB(A) broadband acoustic stimulus was delivered to half of subjects in each time condition, while the other half of the subjects received no noise stimulus. The subjects then performed a counter movement jump according to group assignment. Utilizing a crossover design, subjects performed the same jump with the opposite stimulus condition. Data collected included; flight time (FT), peak force (PF), and time to peak force (TTPF). A 2 x 3 x 2 ANOVA (presence or absence of stimulus x post-AS time of jump x gender) showed no significant effect from acoustic stimulation. Findings suggest that an acoustic stimulus 3, 8 or 15 seconds before a human performs a vertical jump has no significant effect on performance measured by FT, PF or TTPF.;Key Words: Startle, Jumping, Muscular Power, White Noise. |
