Abstract
Objective: To examine the influence of the spinal contour changes on the functioning of trunk muscles in children with idiopathic scoliosis.
Background: In the early stage of scoliosis progression, changes in the sagittal plane often manifest themselves in curving in the lumbar lordosis and curving out of the thoracal scoliosis. An increase or decrease in the size of anteroposterior spinal curvatures may disturb functioning of the trunk muscles.
Method: Thirty five girls (mean age: 14.7 ± 2.3 yr) with idiopathic scoliosis took part in this study. In terms of location, thoracal scoliosis was dominant. Photogrammetry with automatic Moiré fringe analysis system was used to assess the spinal contour. Activity of the spinal flexors and extensors was tested isokinetically at 3 angular velocities: 60, 90 and 120°/s. The measured force-velocity parameters were analysed according to location of the scoliosis (primary thoracal or primary thoraco-lumbar scoliosis), the size of the deformity and posture type: lordotic, kyphotic or equivalent (balanced) (a posture type, where thoracic kyphosis and lumbar lordosis are of similar size – they are balanced).
Results and conclusions: A step-by-step discriminant analysis indicated that parameters associated with muscle endurance were the most diversified regardless of the division criterion applied. It was also revealed that functioning of the trunk muscles was related to the spine asymmetry in the frontal plane as well as on the spinal contour in the sagittal plane.