Postural imbalance in non-treated adolescent idiopathic scoliosis at different periods of progression

Abstract

The aim of this study was to test the hypothesis that imbalance in patients with a severe deformity of the spine is associated with an increase in the sensory integration disorder. This paper is a case comparison study. Patients were divided into three groups: able-bodied (n = 53), observation (n = 23), and pre-brace (n = 26) groups. Time domain parameters (sway area, position and displacement) and structural posturographic parameters [mean distance (MD) and mean peak (MP)] were calculated from the COP excursion using a force platform. A sensory integration disorder could be an important factor in the progression of the scoliotic curve. Significant differences were found in time domain between observation, pre-brace and able-bodied groups. The results for the structural posturographic parameters showed significant differences between the pre-brace and the able-bodied groups (P = 0.018 MD and P = 0.02 MP) demonstrating a perturbation in sensory integration system by an increase of imbalance. The absence of statistical difference between the observation and the pre-brace groups for the structural posturographic parameters indicates a perturbation of sensory integration system associated with curve progression. Our study has demonstrated that the pre-brace group is less stable than the able-bodied group. The severity of scoliosis in pre-brace scoliotic girls could be related to an increase in the sensory integration disorder.

Figures

Fig. 1

Excursion of the COP a for an able-bodied subject and b a scoliotic girl

Fig. 2

Mean COP position in the a antero-posterior and b medio-lateral directions for the able-bodied, the observation and pre-brace groups. Asterisks denote significant differences for P < 0.05

Fig. 3

Sway area for the able-bodied, the observation and pre-brace groups. Asterisk denote significant differences for P < 0.05

Fig. 4

Sum of the COP displacements in the a COPAP and b COPML between for the able-bodied, the observation and pre-brace groups. Asterisks denote significant differences for P < 0.05

Fig. 5

Mean distance of the COP between the able-bodied, the observation and pre-brace groups. Asterisk denote significant differences for P < 0.05

Fig. 6

Mean peak of the COP between the able-bodied, the observation and pre-brace groups. Asterisk denote significant differences for P < 0.05