A Study of the Effects of Whole-Body plus or minus a(z) Vibration on Postural Sway

摘要

An experiment is described, the purpose of which was to determine the effects of whole body, plus or minus a(z) vibration on the amplitude and frequencies of postural sway in human subjects. A platform, supported by two force cells and embodying transducers sensitive to applied vertical load, was used to measure the sway of standing subjects. The standard deviation of lateral sway was found to vary between 1.0 and 3.7 lb prior to vibration. Frequency analysis showed that the power lay mainly in the range from 0.01 to 1.0 Hz. Vibration exposure induced small and inconsistent changes in some spectral components of sway and some of these changes were statistically significant. These effects of vibration on sway amplitude and frequency are discussed. (Author)