Influence of different types of progressive idiopathic scoliosis on static and dynamic postural control

STUDY DESIGN: Balance control assessment of static and dynamic conditions was performed to study the effects of progressive idiopathic scoliosis on postural control in 102 adolescents. OBJECTIVE: To determine how the type and location of idiopathic scoliosis may affect global balance control. SUMMARY OF BACKGROUND DATA: Idiopathic scoliosis may impair postural control components, but the repercussions for global balance are relatively mild. METHODS: The following four different types of idiopathic scoliosis were compared: thoracic (n = 36), thoracolumbar (n = 22), lumbar (n = 23), and double major (n = 21) curves. Center of foot pressure displacements and electromyographic responses were recorded using static and dynamic posturographic tests (single and fast upward tilt, slow sinusoidal oscillations). RESULTS: The major criteria of postural control were better in the double major group for all the tests. In the static test, the patients with high major curves performed better than those with low major curves. In the fast dynamic test, similar latency values were observed in all the groups. In the slow dynamic test, better results were observed for the patients with low major curves. CONCLUSIONS: These data demonstrate that idiopathic scoliosis indeed alters balance control, with different hierarchies, from the best to the worst as follows: double major, thoracic, thoracolumbar, and lumbar curves in the static test and double major, lumbar, thoracolumbar, and thoracic curves in the slow dynamic test. The location of the major curve appeared to be important, with an effect on lateral disequilibrium and vestibular symmetry. The absence of anomaly in the fast dynamic test suggests that the type of scoliosis does not impair proprioception.