Attentional requirements of walking in spinal cord injured patients compared to normal subjects

Study Design: Recent developments in the field of rehabilitation and the increase in the number of incomplete spinal cord injured subjects (SCI) emphasize the importance of studying the walking behavior of that population. Objectives: Attentional requirements were measured in spinal cord injured subjects during sitting, standing and walking and compared to a healthy group for the same tasks and walking at a similar speed. Methods: Auditory stimuli and verbal responses were used to measure the attentional demands in the three experimental tasks. Results: For both static tasks, SCI subjects were faster than the normal group. During walking at preferred speed, the normal group is significantly faster than the SCI subjects are. No difference was found between the two groups when the normal group walked at a similar speed. However, SCI subjects need to allocate significantly more attentional resource to walking than the normal. SCI patients also showed slower reaction times when the stimuli were presented during the single-support phase of walking. Kinematics analysis revealed that SCI subjects produced longer cycle duration than the normal group even when they walked at a match speed. Although variability in the cycle duration and the cycle length were comparable between the two groups, when the normal group walked at a slower speed, they were significantly more variable than the SCI subjects. Conclusion: Walking for SCI patients is cognitively challenging. Walking speed seems to be an important factor associated with attentional demands.