Assessing walking ability in subjects with spinal cord injury: Validity and reliability of 3 walking tests

Objective: To assess the validity and reliability of 3 timed walking tests (Timed Up & Go [TUG], 10-meter walk test [10MWT], 6-minute walk test) in subjects with spinal cord injury (SCI). Design: Cross-sectional study and repeated assessments. Setting: The SCI center of a university hospital in Switzerland. Participants: Validity was assessed by using the data of 75 patients with SCI, and reliability was determined with 22 patients with SCI. Intervention: Patients performed the timed tests and the Walking Index for Spinal Cord Injury II (WISCI II) on the same day. Three measurements within 7 days were taken to assess reliability. Main Outcome Measures: The measures were scatterplots, correlation coefficients (r), and the Bland-Altman plot. Validity was determined in patients with different walking abilities. Results: Overall, correlation of the 3 timed walking tests was excellent with each other (\r\>.88) and moderate with the WISCI II (\r\>.60). The correlation between the timed tests for patients with poor walking ability remained high (\r\>.70) but decreased in WISCI II (\r\<.35). High correlation coefficients (r>.97) were found for intra- and interrater reliability. However, TUG and 10MWT reliability were negatively influenced by a poor walking function. Conclusions: The 3 timed tests are valid and reliable measures for assessing walking function in patients with SCI.