Lamontagne Anouk, Fung Joyce
School of Physical and Occupational Therapy, McGill University, Montreal, Canada.
Neurorehabil Neural Repair. 2009 Mar-Apr;23(3):256-66. doi: 10.1177/1545968308324549. Epub 2008 Dec 5.
Steering of locomotion is a complex task involving stabilizing and anticipatory orienting behavior essential for the maintenance of balance and for establishing a stable frame of reference for future motor and sensory events. How these mechanisms are affected by stroke remains unknown.
To compare locomotor steering behavior between stroke and healthy individuals and to determine whether steering abilities are influenced by walking speed, turning direction and walking capacity in stroke individuals.
Gaze and body kinematics were recorded in 8 stroke and 7 healthy individuals while walking and turning in response to a visual cue. Horizontal orientation of gaze, head, thorax, pelvis, and feet with respect to spatial and heading coordinates were examined.
Temporal and spatial coordination of gaze and body movements revealed stabilizing and anticipatory orienting mechanisms in the healthy individuals. Changing walking speed affected the onset time but not the sequencing of segment reorientation. In the individuals with stroke, abnormally large and uncoordinated head and gaze motion were observed. The sequence of gaze, head, thorax and pelvis horizontal reorientation also was also disrupted. Alterations in orienting behaviors were more pronounced at the slowest walking speeds and turning to the nonparetic side in 3 of the most severely disabled individuals.
The results in this convenience sample of slow and faster walkers suggest that stroke alters the stabilizing and orienting behavior during steering of locomotion. Such alterations are not caused by the inherently slow walking speed, but rather by a combination of biomechanical factors and defective sensorimotor integration, including altered vestibulo-ocular reflexes.
运动转向是一项复杂的任务，涉及稳定和预期定向行为，这对于维持平衡以及为未来的运动和感觉事件建立稳定的参考框架至关重要。中风如何影响这些机制尚不清楚。
比较中风患者与健康个体之间的运动转向行为，并确定中风个体的转向能力是否受步行速度、转向方向和步行能力的影响。
记录了8名中风患者和7名健康个体在响应视觉提示进行行走和转弯时的注视和身体运动学。检查了注视、头部、胸部、骨盆和双脚相对于空间和行进坐标的水平方向。
注视和身体运动的时间和空间协调性揭示了健康个体中的稳定和预期定向机制。改变步行速度会影响节段重新定向的开始时间，但不会影响其顺序。在中风患者中，观察到头部和注视运动异常大且不协调。注视、头部、胸部和骨盆水平重新定向的顺序也受到破坏。在最慢的步行速度下以及在3名最严重残疾个体中转向非瘫痪侧时，定向行为的改变更为明显。
在这个包括慢速和快速步行者的便利样本中的结果表明，中风会改变运动转向过程中的稳定和定向行为。这种改变不是由固有的慢步行速度引起的，而是由生物力学因素和感觉运动整合缺陷的组合引起的，包括改变的前庭眼反射。
