A preliminary study on electromyographic analysis of the paraspinal musculature in idiopathic scoliosis

Abstract

The paraspinal muscles have been implicated as a major causative factor in the progression of idiopathic scoliosis. Therefore, the objectives of this preliminary study were to measure the electromyographic activity (EMG) of the paraspinal muscles to determine its relationship to progression of the scoliotic curve. Idiopathic scoliotic patients were selected and identified afterwards on curve progression. The EMG activity on both sides of the spine was measured in a set of standardized postures using bipolar surface electrodes at the apex and two end vertebrae of the scoliotic curve. An EMG ratio involving measurements of the EMG activity on the convex and concave sides of the scoliotic curve was used to evaluate the paraspinal muscles. Enhanced EMG ratios at the apex of the scoliotic curve were found in both groups during sitting and standing. The most interesting finding was that children with progression of the curve also showed enhanced EMG ratios at the lower end vertebra of the curve. The EMG ratios between the groups were significantly different from each other at the apex and end vertebrae for several test conditions. Overlap in the EMG-ratio ranges made differentiation difficult for prediction of the progression of the individual scoliosis patient. However, the EMG ratio at the lower end vertebra of the scoliotic curve is significantly higher than 1 in all test conditions in the group of children with subsequent progression of the curve, whereas it is always normal in the non-progressive group. Therefore, EMG of the paraspinal muscles might be of value for prediction of progression in idiopathic scoliosis.

Predicting Curve Progression in Adolescent Idiopathic Scoliosis - An Outline of Different Indicators of Growth

“…As mentioned earlier, Cheung et al 2,8 found a relationship between curve progression and altered electromyography ratios of the convex and concave sides of the curve. An electromyography was made of the paraspinal muscles in order to determine the ratios of muscle activity on the convex and concave side of the main scoliotic curve.…”

“…A promising method was shown b y C h e u n g e t a l 2,8 , who found a relationship between curve progression and altered electromyography ratios of the convex and concave sides of the curve. This will be discussed later.…”

Emerging Technology and Analytical Techniques for the Clinical Assessment of Scoliosis

“…These models are in agreement with emerging evidence from biomechanical and neurophysiologic measures that suggest dysfunction of the neuromuscular system may be an additional factor and indicator of progression risk in IS. This evidence is drawn from studies that have demonstrated increased asymmetry in paraspinal muscle activity [27,28,29], altered sensory weighting [30], and postural control [31]. Of these studies, only a few have focused on identifying the predictive ability of neuromuscular measures [27,28,29].…”

“…This evidence is drawn from studies that have demonstrated increased asymmetry in paraspinal muscle activity [27,28,29], altered sensory weighting [30], and postural control [31]. Of these studies, only a few have focused on identifying the predictive ability of neuromuscular measures [27,28,29]. For example, in patients who have IS, the presence of asymmetrical activation of the paraspinal muscles when standing quietly upright has been found to have a 68 % probability of progression, which increases to 80 % when combined with growth velocity [28].…”

Differences in Standing and Sitting Postures of Youth with Idiopathic Scoliosis from Quantitative Analysis of Digital Photographs

“…This progression is attributable to biomechanical factors such as modified trunk alignment and body weight influences which create modifications in muscular moments acting on the spine especially during growth spurt [5,17,35,43]. To restore good posture and to prevent scoliosis progression, physiotherapists work on muscle balance.…”