Postural Stability and Dynamic Balance in Adult Spinal Deformity: Prospective Pilot Study

Objective We sought to evaluate dynamic balance and postural stability in patients with adult spinal deformity (ASD) compared with published age-matched normative data. Methods Eleven patients with ASD were prospectively enrolled. Postural stability was tested using static and dynamic posturography; patients stood on a movable platform with an integrated force plate and performed standardized sensory organization testing (SOT), evaluating the influence of sensory processing on postural stability under 6 conditions, and motor control testing, assessing reflexive postural reactions to an external perturbation. Patient performance was compared with that of published age-matched controls. Quality of life metrics included scores on the Scoliosis Research Society−22 questionnaire, SF-36, and Morse Fall Scale. Correlations between postural stability and radiographic measurements were performed. Results ASD patients demonstrated significantly lower SOT scores (P ≤ 0.03) in 5 of 6 conditions tested and greater latency of limb movement during backward translation (P = 0.04) compared with controls. Lower SOT scores were associated with a history of falls. ASD patients who self-reported falling in the previous 6 months, when compared with nonfallers, demonstrated significantly lower SOT scores (P = 0.04) and significantly lower Scoliosis Research Society−22 self-image subscores (P = 0.003). Thoracic kyphosis and mediolateral sway (predictor of falls) were positively correlated in the eyes-open and eyes-closed conditions (P ≤ 0.04). Conclusions ASD patients demonstrated impaired postural stability, diminished sensory integration, and delayed response to external perturbations compared with normal control data. Postural stability and quality of life metrics correlated with self-reported falls. These findings suggest that ASD patients have abnormal postural stability and may be at elevated risk of falls.