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

Study Design: Recent developments in the field of rehabilitation and the in crease in the number of incomplete spinal cord injured subjects (SCI) empha size the importance of studying the walking behavior of that population. Objectives: Attentional requirements were measured in spinal cord injured s ubjects during sitting, standing and walking and compared to a healthy grou p for the same tasks and walking at a similar speed. Methods: Auditory stimuli and verbal responses were used to measure the att entional demands in the three experimental tasks. Results: For both static tasks, SCI subjects were faster than the normal gr oup. During walking at preferred speed, the normal group is significantly f aster than the SCI subjects are. No difference was found between the two gr oups when the normal group walked at a similar speed. However, SCI subjects need to allocate significantly more attentional resource to walking than t he normal. SCI patients also showed slower reaction times when the stimuli were presented during the single-support phase of walking. Kinematics analy sis revealed that SCI subjects produced longer cycle duration than the norm al group even when they walked at a match speed. Although variability in th e cycle duration and the cycle length were comparable between the two group s, 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 sp eed seems to be an important factor associated with attentional demands.