The patterns of time domain indexes of surface electromyographic signals of adolescent idiopathic scoliosis patients′ paraspinal muscles

Objective: Using surface electromyographic (sEMG) techniques to investigate the patterns of time domain indexes of surface electromyographic signals of adolescent idiopathic scoliosis (AIS) patients′ paraspinal muscles. Method: Twenty-five AIS patients were enrolled, included 7 males and 18 females, aged 11 to 21 years. Forteen healthy adolescents, included 4 males and 10 females, aged 12 to 19 years, were set as control. Adolescents in both groups undertook the Biering Sorensen test (BST), the object-lifting test and semi-bridge test. A ME3000P sEMG instrument was applied to record the electromyographic activities of paraspinal muscles (convex /concave) of all subjects, and the time domain indexes: averaged EMG parameters (AEMG) and spectrum area (SPA) were analyzed. Result: The differences of AEMGs and SPAs between the convex side and the concave side of paraspinal muscles at the zone of apex vertebrae of AIS patients were of statistic significance (AEMGs: convex side 106.76± 47.73μV/s vs concave side 67.93±26.11μV/s, SPAs: convex side 11.01±8.81m2 vs concave side 4.38±3.14 m2,both P 0.01). The AEMGs of healthy controls′ paraspinal muscles on both sides showed no significant difference. Conclusion: Electromyographic activities of paraspinal muscles (convex /concave) at the zone of apex vertebrae of AIS patients are asymmetric. sEMG can be one of the objective examinations used to evaluate the differences of electromyographic activities of paraspinal muscles(convex /concave) of AIS patients, and may have a promising value in clinical practice.