Electromyographic activity of erector spinae muscles using ultrasound images and SENIAM protocol in patients with adolescent idiopathic scoliosis

Background & Measurements of muscle activity in scoliosis has clinical importance. The aim of this study was to compare the effects of electrode placement method based on SENIAM with ultrasound method on the activation levels of erector spinae muscles in patients with adolescent idiopathic scoliosis.
10 female idiopathic scoliosis patients with double curvature participated in this study.
During superman, upper arm abduction, and quadrupt exercises, the activity of erector spinae muscles at T6, T10, and L3 levels were measured using a 16 channel BTS FREE EMG 300 EMG system with surface electrodes. In the first method, electrodes’ direction was placed based on SENIAM protocol, and then in the second method, they were based on the ultrasound images.
The differences between the directions of electrodes in two methods were 13.3º ± 8.22º. There was not any significant difference between methods on the amplitudes of the EMG activities of erector spinae muscles (p>0.05).
In both methods, the ipsilateral muscles to the arm movements displayed higher activity than the contralateral muscles.
The direction of electrodes in ultrasound method was significantly different from that of the SENIAM method. However, this difference did not alter the amplitudes of the EMG signals. It seems that the application of ultrasound in EMG measurements in scoliosis is not necessary. However, the effects of ultrasound technique on EMG parameters other than the amplitude need further analysis.