Chien Jung Hung, Mukherjee Mukul, Siu Ka-Chun, Stergiou Nicholas
Biomechanics Research Building, College of Education, University of Nebraska at Omaha, 6160 University Drive, Omaha, NE, 68182, USA.
Department of Environmental, Agricultural & Occupational Health, College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA.
Ann Biomed Eng. 2016 May;44(5):1625-35. doi: 10.1007/s10439-015-1440-2. Epub 2015 Sep 2.
When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of sway variability was evaluated from all conditions. The results showed that in the anterior posterior direction somatosensory input is crucial for postural control for both walking and standing; visual input also had an effect but was not as prominent as the somatosensory input. In the medial lateral direction and with respect to walking, visual input has a much larger effect than somatosensory input. This is possibly due to the added contributions by peripheral vision during walking; in standing such contributions may not be as significant for postural control. In sum, as sensory conflict increases more rigid and regular sway patterns are found during standing confirming the previous results presented in the literature, however the opposite was the case with walking where more exploratory and adaptive movement patterns are present.
在感觉冲突增加的情况下维持姿势稳定性时，会采用一种更僵硬的反应，即可用的自由度基本被冻结。本研究调查了在姿势控制的更动态情况下（如行走时）是否也会采用这种策略。本研究试图通过使用运动感觉组织测试（LSOT）来回答这个问题。该设备结合了受感觉组织测试（SOT）启发的视觉和体感系统扰动。十名健康的年轻成年人进行了传统SOT的六种情况以及LSOT上相应的六种情况。从所有情况中评估了摇摆变异性的时间结构。结果表明，在前后方向上，体感输入对于行走和站立时的姿势控制都至关重要；视觉输入也有影响，但不如体感输入突出。在内外侧方向以及对于行走而言，视觉输入的影响比体感输入大得多。这可能是由于行走过程中周边视觉的额外贡献；在站立时，这种贡献对于姿势控制可能不那么重要。总之，随着感觉冲突增加，站立时会发现更僵硬和规则的摇摆模式，这证实了文献中先前呈现的结果，然而行走时情况相反，会出现更多探索性和适应性的运动模式。
