Improving walking assessment in subjects with an incomplete spinal cord injury: responsiveness

Abstract

Prospective longitudinal study. To investigate the responsiveness of the Walking Index for Spinal Cord Injury II (WISCI II), 6-Min Walk (6MWT) and 10-Meter Walk Tests (10MWT) for the assessment of walking capacity in incomplete spinal cord injury (iSCI) and to validate these tests with the lower extremity motor score (LEMS). European Multicenter Study of Human Spinal Cord Injury. The walking tests of 22 iSCI subjects who achieved functional ambulation and could stand or walk within 1 month after iSCI were analyzed at 3, 6 and 12 months after injury. Responsiveness was assessed by determining differences between the time intervals, and Spearman's correlation coefficient was calculated to quantify validity. All walking tests were able to assess the improvement of walking capacity within the first 3 months after injury. Between 3 and 6 months, only the 10MWT and 6MWT were responsive to the ongoing improvement in locomotor capacity. Overall, correlations between the tests were good within the first month, but became poorer over time. The 6MWT and 10MWT were more responsive in demonstrating an improvement in walking capacity compared to the WISCI II. The testing of functional outcome after iSCI as provided by the ordinal ASIA motor score can be improved by interval scaled measures. This allows increasing the responsiveness of functional outcome measures and should be advantageous in assessing therapeutical approaches in iSCI subjects. In iSCI subjects with walking ability, we recommend the additional use of timed tests to monitor improvement in locomotor capacity.