The Acute Effects of Whole Body Vibration on Postural Control Measures in Elderly Women

Abstract

Injuries resulting from a fall incident have been documented as a leading cause of trauma in older adults in the United States. Resistance training and chronic whole body vibration (WBV) have been employed to reduce age related attenuation of reflexive postural control measures. Due to differences in study designs, the acute results of WBV have been mixed. PURPOSE: The purpose of this project was to analyze the acute effects of WBV on functional postural control measures in women between the ages of 60-75 years. METHODS: Fifteen healthy females (68.3 + 5.0 yrs), able to complete "3 up and go tests" in less than 8.5 seconds, were included in the study. After a standard warm-up, sway velocity and root-mean-square (RMS) sway measures were obtained using an Equitest Posture Platform (NeuroCom, Inc.) sensory organization test (SOT) battery, which elicits responses from each of the 3 sensory systems individually or in combination. Following a 5 minute rest, participants were exposed to 3 20 second bouts of WBV (30 Hz, 2-4 mm @ 135° knee flexion), separated by 1 minute. At the conclusion of the vibration exposure, participants completed the same postural control tests preceded by a 1 minute rest. RESULTS: Analysis of variance was measured independently for the 6 postural stability-testing conditions. Statistically significant (p < 0.05) within participants main effects were seen in the eyes closed with the platform and visual surrounds stable (EC), eyes closed with the platform sway referenced (ECSR), and the eyes open with the platform and visual surround sway referenced (EOSRVR) conditions in both medial/lateral and anterior/posterior directions. CONCLUSIONS: Results suggest that WBV had no significant effects on overall postural control measures in the population. Future research should assess balance at distinct time points post vibration exposure to determine the residual effects of exposure to WBV.