[Idiopathic scoliosis by spinal fusion and brace treatment: evaluation by gait analysis]

We have investigated the differences in gait between 68 idiopathic scoliosis patients and 186 normal subjects, and differences in gait before and after treatment of the scoliosis by two different methods. The idiopathic scoliosis patients were divided into two groups according to which treatment they had received; one group of 17 cases had been treated by spinal fusion and the other group of 51 cases had been treated by bracing. Gait analysis was performed using a 1.2 m wide and 10.8 m long force plate walkway. Three components of each step (the lateral, horizontal and vertical components) were measured. Gait velocity, step length, step width and cadence were evaluated as temporal and distance factors, and symmetry, reappearance, smoothness, sway, rhythm and impact were evaluated as gait factors.

Before treatment, there was no difference in any temporal or distance factor between the scoliosis patients and the normal subjects. However, the index of symmetry, and of sway, in the vertical component prior to treatment in the scoliosis patients was significantly inferior to that in the normal subjects. A positive correlation was found between the index of sway in the vertical component and the pretreatment Cobb angle. This correlation was found in the right-convex single curve group and in the double curve group, but not in the left-convex single curve group. After spinal fusion, the step width became wider and the index of sway significantly improved, but index of symmetry was unchanged. No gait factor became worse postoperatively. In contrast, in the bracing group, the step width became wider, but the index of symmetry, and of sway in the vertical component, did not improve with the brace. The gait of scoliosis patients could be objectively and quantitatively analyzed by the force plate. The gait analysis was useful for evaluating the effects of spinal fusion, and of brace treatment, in idiopathic scoliosis patients.