The relationship between electromyographic amplitude of paravertebral muscles and curve progression in Chinese adolescents with idiopathic scoliosis: a preliminary study

Abstract

Introduction: The imbalanced electromyographic activity (EMG) of paravertebral muscle has been commonly presented in adolescent idiopathic scoliosis (AIS). This study aimed to define the relationship between EMG ratio of paravertebral muscles and progression risk in patients with AIS. Materials and Methods: This was a preliminary, cohort matched study recruiting participants with AIS and age- and gender-matched healthy controls between January and July 2020. Participants with AIS were classified with major thoracic curves, major lumbar curves and double major curves. The paravertebral EMG ratio was defined as the root mean square (rms) value of EMG amplitudes of the total recording time of a convexity pair divided by a concavity pair at the trapezius, upper end vertebra, apical vertebra, and LEV levels. The progression risk was determined using the Lonstein and Carlson Risk of progression scale. The primary outcome was correlation analysis of the progression risk value with each paravertebral EMG ratio. Results: A total of 96 participants were recruited. A pilot study revealed a satisfactory reliability of the rms-EMG (ICC3,3=0.99) measures. Multiple regression analysis revealed that the rms-EMG ratio at the LEV was strongly correlated with progression risk of participants with AIS (R=0.69, p<0.05; R=0.81, p<0.01). Additionally, we found that the rms-EMG ratio at the transitional vertebral level was significantly correlated with curve progression in the double major curves (R=0.63, p<0.01). Discussion and Conclusion: The higher rms-EMG ratio at the LEV was significantly correlated with the curve progression in this study, which implies that paravertebral EMG may be valuable for predicting curve progressions.