evaluation of trunk muscle activation during the two directions of flexi-bar exercise in people with and without low back pain

Introduction: the flexible-bar with a small amplitude of 5 hz, which transmitsvibrations to the trunk, enables the activation of the core muscles that can be used torehabilitate subjects with low back pain. two types of exercise direction that can affecttrunk muscles of low back pain subjects similar control group are not known. this studyaimed to evaluate and compare exercises with two directions of the oscillating flexiblepoles in people with and without low back pain (lbp).materials and methods: twelve women with mean±sd age of 28.75±2.92 years, andbody mass index (bmi) of 22.31±2.10 kg/m2 and a history of low back pain, and 12 healthysubjects with mean±sd age of 28.75±2.49 years and bmi of 21.59±1.50 kg/m2 voluntarilyparticipated in this study. the electromyography (emg) signals of trunk muscles weremeasured during two handheld oscillating flexible bars in two directions. the root meanssquare (rms) of signals for each muscle is normalized by the maximum rms.results: the results of comparing two types of exercise in two groups showedsignificant differences for left external oblique (p=0.017), right external internal oblique(0.002), and left internal oblique (0.008). also, the difference in the interaction betweengroup×exercise was significant only for left internal oblique (p=0.026).conclusion: muscle activity in the low back pain group appears different whileperforming exercises with a flexible-bar compared to the control group. this confirmsmotor control impairment in these populations and having different strategies for trunkco-activation during exercise.