The physical impact of fatigue is weakly related to objective walking capacity, while general, physical, cognitive, and psychosocial fatigue impact are weakly to moderately related to subjective walking ability in multiple sclerosis (MS) patients. This according to a recent study that included ambulatory MS patients (n=189) tested at 11 sites. Objective tests of walking capacity included short walking tests (Timed 25-Foot Walk [T25FW], 10-Metre Walk Test [10mWT] and the Timed Up and Go [TUG]), and long walking tests (2- and 6-Minute Walk Tests [MWT]). Fatigue impact was measured by the self-reported modified fatigue impact scale (MFIS) consisting of a total score (MFIS_total) and 3 subscales (MFIS_physical, MFIS_cognitive and MFIS_psychosocial). They found:

• MFIS_total was negatively related with long (6MWT, r = −0.14) and short composite (TUG, r = −0.22) walking measures.
• MFIS_physical showed a significant albeit weak relationship to walking speed in all walking capacity tests (r = −0.22 to −0.33), which persisted in the multivariate linear regression analysis.
• Subjective walking ability (MSWS-12) was related to MFIS_total (r = 0.49), as well as to all other subscales of MFIS (r = 0.24–0.63), showing stronger relationships than objective measures of walking.