Assessment of coordinated activity of the erector spinae muscles based on high-density surface electromyogram in adolescent idiopathic scoliosis patients

English Keywords:Adolescent idiopathic scoliosis  High-density surface electromyography  Paraspinal muscle  Coordinated activity

English Abstract:

  【Abstract】 Objectives： To assess the coordinated activity erector spinae muscles in AIS patient based on high-density surface electromyography(sEMG). Methods: A high-density sEMG array was symmetrically attached on lumbar back along spine for both AIS and healthy subjects, and sEMG signals were collected when the subjects performed two kinds of torso movements(upright standing and trunk flexion). For each channel, its root mean square(RMS) values were calculated from the sEMG recordings and were smoothened with interpolation method. Then the RMS values of all the channels were used to create a sEMG topography to analyze the muscle coordination activities. Results: Our experimental results demonstrated that during upright standing and trunk flexion tasks, those tense activity regions presented a bilateral symmetry in healthy subjects. For AIS patients, their tense activity regions did not have a bilateral symmetry, which was stronger at convex side than at concave side. In upright standing posture, the average RMS value of the strongest region in AIS patients′ convex map was 66.92±12.05μV, greater than 23.77±4.04μV at the concave side. In trunk flexion posture, the average RMS value of the strongest region in AIS patients′ convex map was 192.25±87.62μV, greater than 95.70±25.93μV at concave. sEMG energy at convex side became higher and the ratio to concave got bigger as the increase of Cobb angle. For AIS patients with different Cobb angles, the ratio of those sEMG energy in each column at convex to its symmetrical column at concave showed that the most significant difference was presented at the overlapping region of paraspinal and other muscles belly. Conclusions: The RMS maps of the sEMG in AIS patients were significantly different from those in healthy subjects for both tasks of upright standing and trunk flexion, namely, sEMG energy at convex side was higher than that at concave, which became stronger with the increase of Cobb angle.