视动力刺激对下背痛患者姿势控制的影响

关键词：下背痛  姿势控制  视觉  环境

Keywords:low back pain  postural control  vision  environment

摘要：

      摘要 目的：研究下背痛患者站于不同支撑面接受视动力刺激时的姿势控制特征，为进一步认识下背痛和丰富治疗方案提供新的理论和证据。 方法：选取13例25—40岁的慢性非特异性下背痛患者为实验组，年龄、性别一致的13例健康人作为对照组。测试者站于由随机运动点构成的投影屏幕前，点的运动分为向前汇聚（-）和向后扩散（+）两种，点移动速度有80°/s，40°/s和20°/s 3种。视觉刺激采用刺激—间歇的间断刺激模式，并使用压力平衡板记录每位受试者在平板和软垫两种支撑面上接受视觉刺激时，双侧足底压力中心（COP）的移动情况，包括Y轴峰值移动速度、不同阶段移动幅度标准差（SD）和X轴移动轨迹总长度。 结果：与对照组相比，站于稳定平面时，实验组COP各项参数的变化没有显著性差异（P>0.05）；而站于不稳定平面上，只有接受+40°/s的视觉刺激时，实验组休息中期标准差（SD）值为(3.74±1.22)，对照组为（2.83±0.75），两组有显著性差异（P<0.05）；此外，接受同样刺激时，两组站于不稳平面时COP的各项参数均显著高于稳定平面（P<0.001）。 结论：下背痛患者在任务环境更复杂时，对视觉信息，特别是向后的信息，依赖程度增加，姿势调整效率的降低，提示对下背痛患者异常运动模式的治疗需要考虑任务环境因素。

Abstract:

      Abstract Objective: To investigate the characteristic of chronic nonspecific low back pain(CNLBP)'s posture control in different surfaces by optokinetic stimulation of different velocities, so as to provide new theory and experiment data for further recognizing the CNLBP and enrich its' treatment. Method: Thirteen individuals with CNLBP (age range 25—40 years) and thirteen age,gender-matched control subjects were recruited. Every subject was exposed to random-dot patterns projected on a large screen, the dots' moving direction were contraction(-) and expansion(+), the dots' velocity included 80°/s,40°/s and 20°/s. The visual stimulus used “stimuli--interval” pattern, and applied the force platform to record the peak velocity and different phases' standard deviation（SD） of anterior-posterior center of pressure（COP） displacements and total length of medial-lateral COP sway on the stable surface and soft surface. Result: No difference in COP parameters were observed when standing on the stable surface between the two groups (P>0.05). However, significant more SD of amplitude in the middle phase was seen in the persons with CNLBP when confronting the +40°/s stimuli on the soft surface (3.74±1.22) compared to the healthy individuals(2.83±0.75),（P<0.05）. Besides, when confronting the same stimuli, the parameters of COP displacement on the soft plane were more than that on the stable surface in each group (P<0.001). Conclusion: The subjects of LBP had visual-dependent phenomenon and decreased the efficiency of postural adjustment in the more complicated task and environment, especially optokinectic stimulation in the expansion direction. This result suggested that the treatment to the abnormal motor pattern in LBP patients should take the properties of task and environment factor into account.