The electromyographic responses of paraspinal muscles during isokinetic exercise in adolescents with idiopathic scoliosis with a Cobb's angle less than fifty degrees.

Abstract Analysis of electromyographic (EMG) activities in the back during dynamic exercise is needed because more complex loading on the spine is created in comparison with that during static exercise. The purpose of this study is to investigate the difference in bilateral midback and low-back paraspinal muscle (PSM) activities during performance of different resistance isokinetic exercises in healthy subjects and those with scoliosis. Forty-one healthy subjects and thirty-three subjects with adolescent idiopathic scoliosis (AIS) were enrolled. An isokinetic back system in combination with quantitative surface EMG was used to evaluate the dominant and nondominant PSM activities by analyzing the root mean square (RMS) during isokinetic extension and flexion exercise at velocities of 30 degree/s and 90 degree/s. Significantly higher RMS of EMG were found in the dominant medial and lateral PSM of the lumbar region than the non-dominant muscles in the healthy control group and in those with AIS with smaller curves (