Iran University of Medical Sciences.
Sharif University of Technology.
Motor Control. 2020 Jan 1;24(1):91-112. doi: 10.1123/mc.2018-0032.
The characteristics of postural sway were assessed in quiet standing under three different postural task conditions in 14 patients with nonspecific chronic low back pain and 12 healthy subjects using linear and nonlinear center of pressure parameters. The linear parameters consisted of area, the mean total velocity, sway amplitude, the SD of velocity, and the phase plane portrait. The nonlinear parameters included the Lyapunov exponent, sample entropy, and the correlation dimension. The results showed that the amount of postural sway was higher in the patients with low back pain compared with the healthy subjects. Assessing the nonlinear parameters of the center of pressure showed a lower sample entropy and a higher correlation dimension in the patients with low back pain compared with the healthy subjects. The results of this study demonstrate the greater regularity and higher dimensionality of the center of pressure fluctuations in patients with nonspecific chronic low back pain, which suggests that these patients adopt different postural control strategies to maintain an upright stance.
采用线性和非线性的压力中心参数，对 14 例非特异性慢性下腰痛患者和 12 例健康受试者在三种不同的姿势任务条件下的静立姿势摆动特征进行了评估。线性参数包括面积、平均总速度、摆动幅度、速度的标准差和相平面图像。非线性参数包括 Lyapunov 指数、样本熵和关联维。结果表明，腰痛患者的姿势摆动幅度高于健康受试者。评估压力中心的非线性参数显示，腰痛患者的样本熵较低，而关联维数较高。本研究结果表明，非特异性慢性下腰痛患者的压力中心波动具有更大的规律性和更高的维数，这表明这些患者采用不同的姿势控制策略来维持直立姿势。
