Variations in bioelectric activity during symmetric loading and asymmetric stretching of paraspinal extensors in young adult women with mild single curve scoliosis

Introduction Symmetrical loading and asymmetrical stretching of trunk extensors are applied in scoliosis physiotherapy management. Conflicting evidence is available on trunk erectors' bioelectrical activity during such static exercise, especially in adult subjects. Our purpose was to identify the profile of bioelectrical activity of trunk extensors during static contractions against symmetrical loading with body mass in young adult females with single curve scoliosis, who participated in adolescence in a scoliosis-specific physiotherapy program. Material and Methods. Thirty five females, aged 30.6 +/- 2.7 years, with body weight of 56.8 +/- 4.4 kgs and height 1.64 +/- 0.05 m with single curve thoracic scoliosis, 11-36 Cobb, who in adolescence had attended a scoliosis-specific physiotherapy program, participated. Braced and/or surgically treated subjects were excluded. Characteristics of the integrated EMG were collected and analysed. The measurements were conducted on a subject in prone position at rest, during 20 second static symmetrical erectors' contractions while sustaining elevated trunk and during the same effort, while stretching trunk erectors on the concave side of the curve by extending and reaching the corresponding arm forward. Results. The biopotentials measured on both sides of the spine differed significantly (p<.001) during asymmetrical stretching of the erector muscles on the concave side while extending the trunk. We did not observe such differences in measurements obtained while at rest and during symmetrical contractions without stretching. Conclusions. We observed a beneficial scheme of muscle activity during trunk extension and stretching of the erector muscles on the concave side of the curvature in lying prone position, while extending and reaching forward an arm on the convex side. Significance. These findings could provide a useful remark for exercise prescription for adult patients with single thoracic scoliosis. However, the assumptions need wider studies.