Test-retest reliability of spatial-temporal gait parameters (minute-by-minute) in people with multiple sclerosis during the 6MWT

Abstract

Introduction: People with multiple sclerosis (pwMS) often present walking fatigability (WF), frequently measured through the 6-minute walk test (6MWT) and defined as a 10% decrease in distance walked from the sixth to the first minute (calculated using the distance walk index (DWI)). Objective: Previous studies investigated reliability of spatial-temporal gait parameters in pwMS mostly during short walking but few during prolonged walking (6MWT), in pwMS with WF. Aim: To evaluate the test-retest reliability of spatial-temporal gait parameters minute-by-minute in absolute values in pwMS with and without WF and healthy controls (HC) during the 6MWT. Methods: Thirty-four pwMS (20 with WF, EDSS 4.8±1.2 and 14 without WF, EDSS 5.2±1.2) and 19 HC (30-75 years) were included in the study. The 6MWT was performed two times in two different sessions (5-7 days apart). Spatial-temporal gait parameters (cadence, gait speed, double support, step duration, and stride length) were obtained from APDM (OPAL, USA) sensors. Intraclass correlation coefficients (ICCs) were calculated to assess the reliability of these gait parameters in the three subgroups (with and without WF, and HC). Results: Test-retest reliability for the subgroup with WF was moderate-to-excellent (0.51-0.99) for each minute of the 6MWT, and poor-to-excellent for the subgroups without WF (0.39-0.99) and HC (0.32-0.98), with lowest values at minute 6. Conclusion: Spatial-temporal gait parameters measured minute-by-minute during the 6MWT were reliable in pwMS with walking fatigability. Consistencies of the results were observed over the three groups.