Untitled

Abstract

Usage of the whole-body vibration (WBV) is effective in preventing the ankle injuries caused by increasing neuromuscular activity. The aim of this study was to investigate effective frequencies for neuromuscular activity of ankle muscles. A single-group, repeatedmeasures study design was used. Twenty-three healthy subjects (age 23.91±3.07, BMI 22.66±3.39) participated in this study. This study investigated the effects of WBV on the EMG responses of the Tibialis Anterior (TA), Peroneus Longus (PL), Gastrocnemius Medial (GM) and Lateral heads (GL). The muscle activity was measured with an 8-channel EMG Noraxon MiniDTS system (Noraxon, USA, Inc, Scottsdale, AZ) during 0, 20, 40 and 60 Hz of vibration. The Physio Plate® vibration platform (Physio Plate®, Domino S.R.L, San Vendemiano, Italy) was used to deliver mechanical vibration. Compared with no vibration condition; EMG activity of all ankle muscles were significantly increased from at 60 Hz (123 % in TA, 64 % in PL, 53 % in GM, 77 % in GL) (p<0.01). At 40 Hz of vibration frequency, EMG responses of GM and GL was significantly increased (27 % and 53%, respectively) (p<0.01). Only GL was significantly increased of 33 % at 20 Hz (p<0.01). It could be concluded that using higher frequencies at whole-body vibration exercises are more effective than lower frequencies on ankle muscles' EMG activities. During squat exercises on the WBV platform, higher frequencies should be used to increase ankle muscle activation. 1. Introduction Ankle sprains are accepted as the most common sports and physical activity related injuries [35]. An acute ankle sprain causes pain, function loss and economic burden [31]. Moreover, most of the patients with history of ankle sprain tend to repeat their injury [9]. Because of these reasons emphasis should be put on the importance of preventive intervention for the ankle. Neuromuscular training is one of the popular intervention which is used to prevent ankle sprain and includes challenging the ability of related joints to detect external stimulus and produce desired response to stimulus [10, 31]. Whole-Body Vibration (WBV) trainings take place both in preventive programs and in rehabilitation protocols [22], as neuromuscular training techniques [2, 21] and exercise modality [13]. WBV trainings are exercises performed on a platform that creates an oscillation with certain frequency and amplitude [24]. It is believed that the vibration stimulus can move the muscle spindle to cause stimulation of alpha motor neurons, thereby increasing muscle contraction [19, 26], and motor unit synchronization [14] because muscles try