ABSTRACT
Whole body vibration (WBV) is theorized to enhance neural potentiation of the stretch reflex. The purpose of this study was to determine if WBV affects the quadriceps reflex from a patellar tendon tap. Subjects were 22 volunteers (age 23 +/- 2 yrs, ht 172.8 +/- 10.8 cm, body mass 68.6 +/- 12.3 kg). The stretch reflex was elicited from the dominant leg pre, post, and 30-min post WBV treatment. A matched control group repeated the procedure without WBV. WBV treatment consisted of 5, 1-min bouts at 26 Hz with a 1-min rest period between bouts while maintaining a standardized squatting position. Two-way ANOVAs were used to detect differences between groups over time for vastus medialis (VM) and vastus lateralis (VL) latency, EMG amplitude, electromechanical delay (EMD), and force output. No group x time interactions were detected for latency (VM; F ((2,40)) = 1.20, p = .313: VL; F ((2,40)) = 0.617, p = .544), EMG mean amplitude (VM; F ((2,40)) = 0.169, p = .845: VL; F ((2,40)) = 0.944, p = .398), EMD (VM; F ((2,40)) = 0.715, p = .495: VL; F ((2,40)) = 1.24, p = .301), or quadriceps force (F ((2,40)) = 1.11, p = .341) A single session WBV treatment does not affect the quadriceps stretch reflex in terms of timing or amplitude.