Copyright @ 200 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.7 Vibration Exposure and Biodynamic Responses during Whole-Body Vibration Training

2007. Purpose: Excessive, chronic whole-body vibration (WBV) has a number of negative side effects on the human body, including disorders of the skeletal, digestive, reproductive, visual, and vestibular systems. Whole-body vibration training (WBVT) is intentional exposure to WBV to increase leg muscle strength, bone mineral density, health-related quality of life, and decrease back pain. The purpose of this study was to quantitatively evaluate vibration exposure and biodynamic responses during typical WBVT regimens. Methods: Healthy men and women (N = 16) were recruited to perform slow, unloaded squats during WBVT (30 Hz; 4 mmp-p), during which knee flexion angle (KA), mechanical impedance, head acceleration (Harms), and estimated vibration dose value (eVDV) were measured. WBVT was repeated using two forms of vibration: 1) vertical forces to both feet simultaneously (VV), and 2) upward forces to only one foot at a time (RV). Results: Mechanical impedance varied inversely with KA during RV (effect size, G