Immediate Effect of Warm up by Whole Body Vibration on Accuracy of Force Reproduction of Knee Extensor Muscle in Young Healthy People

Warm up is used for reducing risk of injury and increasing performance prior to practice. Whole body vibration is one of the new methods of warm up that has increasingly been taken into consideration. Despite increased application of this method, its effect on proprioception is not well-known. The aim of the present study was to investigate the effects of whole body vibration on the accuracy of force reproduction as a key indicator of proprioception.
In the current randomized control trial, 44 participants (25 males and 19 females, with 22.02±2.75 years of age and BMI: 21.92 ± 2.33 kg/m2) selected from healthy students of Shahid Beheshti University of Medical Sciences, Tehran, were randomly assigned into two groups: whole body vibration (frequency of 30 Hz and amplitude of 4 mm) and control group (vibration plate inactivated). Participants performed dynamic squats in five minutes with one minute rest interval between each performance on the machine and accuracy of force reproduction of knee extensor muscle was evaluated before and after the intervention. The absolute error, constant error, and variable error were measured to evaluate the participants’ errors in their realization of force sense.
Absolute error and variable error of force in both groups showed significant increase after intervention (P0/05).
According to the results, it seems that immediate effect of this method of warm up reduces accuracy of force production which can be due to fatigue caused by dynamic squat performed five times at one-minute which consequently led to incorrect matching between peripheral and central mechanisms of realization of the force sense. This point should be considered when prescribing the appropriate protocol of warm up.