The Effects of Whole Body Vibration (WBV) And Local Muscle Vibration (LMV) on Peak Torque (PT) And Rate of Torque Development (RTD)

Purpose: Patients with anterior cruciate ligament (ACL) reconstruction have quadriceps dysfunction from arthrogenic muscle inhibition (AMI). AMI increases the risk of post-traumatic osteoarthritis, and current rehabilitation methods do not address AMI. Direct (local muscle vibration-LMV) and indirect (whole body vibration-WBV) vibratory stimuli improve muscle function and may be used for rehabilitation and performance enhancement. The purpose of this study was to compare the effects of WBV and LMV on quadriceps function. Methods: Fifty-six healthy volunteers were randomized to one of three groups: WBV (n=19), LMV (n=19), or Control (n=18). All groups performed isometric squats while receiving their assigned intervention. Voluntary knee extensor peak torque (PT) and rate of torque development (RTD) were measured at baseline and again immediately, 10, and 20 minutes following intervention (WBV, LMV, control) during maximal isometric knee extension on an isokinetic dynamometer. Dependent variables were evaluated using 3 (group) by 4 (time) repeated measures ANOVA. Results: The group by time interaction effect was significant for PT (p = 0.002), and post hoc analyses indicated that PT improved in the WBV group (p < 0.001) from baseline to immediately following intervention, but not in the LMV or control groups. No effects were observed in RTD (p = 0.123). Conclusions: These findings suggest that WBV increases quadriceps PT in healthy individuals immediately following vibration. Therefore, WBV may improve traditional exercise and rehabilitation programs through neuromuscular enhancements. Future research is necessary to investigate the physiological mechanism associated with vibration therapy (VT) and determine the most effective delivery methods and stimulation parameters.Bachelor of Art