Whole body vibration (WBV) has been shown to improve force and power output as well as flexibility and speed, with improvements suggested to result from reduced electromechanical delays, improved rate of force development, and sensitivity of muscle spindles. Fixed frequency studies on postural control have been somewhat equivocal; however, individualized frequency protocols have shown promising results in other motor tasks. To assess this, 18 healthy young adults experienced three 4-minute WBV sessions with postural control assessed before vibration, after multiple exposures, and during recovery, with altered levels of sensory information available to the participants. Sway velocity, sway path length, and sway area were assessed in each environment. Study findings revealed that stability was impacted following WBV, with more challenging environments eliciting improvements persisting for 20 minutes. When the environment was less challenging, postural stability was impaired; however, the effects dissipated quickly (10-20 min). It was determined that exposure to individualized frequency WBV served to impair postural control when the challenge was low, but resulted in heightened stability when the overall challenge was high and vestibular information was needed for stability.
D. Clark Dickin and Jacqueline E. Heath are with the Biomechanics Laboratory at Ball State University in Muncie, IN.