The effect of Flexi bar on activation level of erector spine muscles at deferent positions

Oscillatory devises like Bodyblade and Flexi-bar have been popular in USA and Europe as a kind of exercise therapy. Many controversial researches have been done to find out the activation pattern differences of some muscles during oscillation with these devices. In this study we compare erector spine muscle EMG activity in lumbar, thoracic and cervical region during Flexi-bar unilateral oscillation at 3 different weight bearing positions. Surface EMG signal were bilaterally collected from erector spine muscles from 12 healthy volunteers during double stance and single stance on the right and left leg. We compared regular EMG activity of muscles which was normalized by maximal voluntary contraction during Flexi-bar oscillation. Repeated measures ANOVA revealed significant deference between muscular activity of left and right side in cervical reign (P = 0.012), in thoracic (P = 0.008) and in lumbar reign (P < 0.001). The comparison across different standing positions were not statistically significant. Flexi bar oscillation in position of this study resulted different level of activity in Erector spine muscles. Studies on another postures and muscles can help us to choose the most appropriate position of exercise for our patients.