Despite the widespread use of whole-body vibration (WBV), especially in recent years, its neurophysiological mechanism is still unclear and it is yet to be determined whether acute and short-term WBV exposure produce neurogenic enhancement for agility.
To compare the acute and short-term effects of WBV on the H-reflex-recruitment curve and agility.
Clinical electrophysiology laboratory.
20 nonathlete male volunteers (mean age 24.85 ± 3.03 y).
Main Outcome Measures:
Subjects were randomly divided into 2 groups, H-reflex and agility. In the sham protocol, subjects stood on the turned-off vibration plate while maintaining the semisquat position, and then, after a 2-wk washout, vibration-training sessions were performed in the same position with a frequency of 30 Hz and an amplitude of 3 mm. H-reflex-recruitment curve was recorded and the agility test of a shuttle run was performed before and after the first session and also 48 h after the 11th session in both sham and vibration-training protocols.
Acute effects of WBV training caused a significant decrease of threshold amplitude and H-max/M-max (P = .01 and P = .04, respectively). Short-term WBV training significantly decreased the threshold intensity of the soleus H-reflex-recruitment curve (P = .01) and caused a decrease and increase respectively, in the threshold intensity and the area under the recruitment curve.
The results suggest an inhibitory effect of acute WBV training on the H-reflex response.
Ahmadi, Torkaman, Kahrizi, and Dadashi Arani are with the Dept of Physical Therapy, Tarbiat Modares University, Tehran, Iran. Ghabaee is with the Dept of Neurology, Tehran University of Medical Sciences, Tehran, Iran.