A corrected version of the Timed-25 Foot Walk Test with a dynamic start to capture the maximum ambulation speed in multiple sclerosis patients

Background: No clinical test is currently available and validated to measure the maximum walking speed (WS) of multiple sclerosis (MS) patients. Since the Timed 25-Foot Walk Test (T25FW) is performed with a static start, it takes a significant proportion of the distance for MS patients to reach their maximum pace. Objectives: In order to capture the maximum WS and to quantify the relative impact of the accelerating phase during the first meters, we compared the classical T25FW with a modified version (T25FW(+)) allowing a dynamic start after a 3 meters run-up. Methods: Sixty-four MS patients and 30 healthy subjects performed successively the T25FW and the T25FW(+). Results: The T25FW(+) was performed faster than the T25FW for the vast majority of MS and healthy subjects. In the MS population, the mean relative gain of speed due to the dynamic start on T25FW was independent from the EDSS and from the level of ambulation impairment. Compared to healthy subjects, the relative difference between dynamic versus static start was more important in the MS population even in patients devoid of apparent gait impairment according to the T25FW. Conclusion: The T25FW(+) allows a more accurate measurement of the maximum WS of MS patients, which is a prerequisite to reliably evaluate deceleration over longer distance tests. Indirect arguments suggest that the time to reach the maximum WS may be partially influenced by the cognitive impairment status. The maximum WS and the capacity of MS patients to accelerate on a specific distance may be independently regulated and assessed separately in clinical trials and rehabilitation programs.