Dynamic and Static Balance Evaluation of Scoliosis Based on Plantar Force Sensors

Scoliosis is a three-dimensional deformity of the spine that severely affects the healthy growth of adolescents. This disease may lead to impaired static and dynamic balance, severely affecting quality of life. Currently, the method for assessing scoliosis balance is X-ray evaluation, which cannot combine multiple postures for static-dynamic integrated assessment. Plantar force sensors can capture force signals, calculate spatial, mechanical, and gait cycle parameters, and assess changes in both dynamic and static balance in scoliosis patients. In this study, we collected plantar force sensor data and X-ray information from patients with scoliosis and healthy participants under four postures: standing, bending, marking time, and walking. We extracted spatial, mechanical, and gait features, applied a random forest algorithm to determine the feature importance and classification changes. Even in mild scoliosis, balance ability in both static and dynamic postures is altered. In static postures, balance declined in scoliosis patients are primarily concentrated on mechanical parameters, whereas in dynamic postures, changes are more evident in spatial and gait parameters. This decline in balance ability is correlated with the Cobb angle measured on full-spine X-rays in the standing position (R2=0.5063-0.6989). Therefore, the combined analysis of dynamic and static conditions using force sensors can effectively assess the balance ability in patients with scoliosis. 

脊柱侧凸（Scoliosis）是一种三维脊柱畸形，会严重影响青少年的健康生长发育。该疾病可引发静态与动态平衡能力受损，严重降低患者的生活质量。当前，评估脊柱侧凸患者平衡状态的主流方法为X射线评估，但该方法无法结合多种姿势开展动静一体化评估。足底压力传感器（plantar force sensors）可采集压力信号，计算空间、力学及步态周期参数，以此评估脊柱侧凸患者的静态与动态平衡变化。本研究收集了脊柱侧凸患者与健康受试者在站立、弯腰、踏步与行走四种姿势下的足底压力传感器数据及X射线信息。本研究提取了空间、力学及步态特征，并应用随机森林算法（random forest algorithm）确定特征重要性与分类变化。即便为轻度脊柱侧凸患者，其静态与动态姿势下的平衡能力均已出现异常改变。在静态姿势下，脊柱侧凸患者的平衡能力下降主要集中于力学参数维度；而在动态姿势下，空间与步态参数的变化更为显著。该平衡能力下降与站立位全脊柱X射线测量所得的Cobb角（Cobb angle）呈显著相关（R²=0.5063~0.6989）。因此，通过压力传感器联合分析动静状态，可有效评估脊柱侧凸患者的平衡能力。