Performance fatigability during gait in adults with Charcot-Marie-Tooth disease

Background: Fatigue is common in people with Charcot-Marie-Tooth (pwCMT) disease. However, no studies have characterized performance fatigability during gait in this population. Characterizing performance fatigability during gait, and assessing its relation to life satisfaction could improve understanding and treatment of mobility challenges in pwCMT. Research questions: How do gait outcomes change with fatigue in pwCMT? Do these changes relate to life satisfaction? Methods: 31 pwCMT completed a 6-minute, fast-as-possible walk while gait outcomes were captured via inertial sensors. Gait outcomes were separated into six sequential bins of equal size. The mean value, variability, and asymmetry (step time only) of outcomes were calculated for each bin. Perceived fatigue and general life satisfaction were assessed via questionnaire. Results: Of the five mean gait outcomes measured, four showed statistically significant changes over the 6-minute fast-as-possible walk: velocity (reduced; p = 0.008); cadence (reduced; p < 0.001), step time (increased; p < 0.001), and trunk ROM (increased; p = 0.032). Of the four variability and one asymmetry outcomes, only stride length variability changed during the walking task (p = 0.015), decreasing from bins 1–2, and remaining stable for bins 2–6. Changes in velocity, cadence, step time were related to general life satisfaction (0.038 < ps<0.04), but not perceived fatigue (ps>0.343). Significance: pwCMT exhibit statistically significant changes in mean gait outcomes, but not variability outcomes, across a 6-minute, fast-as-possible walking bout. Changes correlated to life satisfaction, suggesting performance fatigability during gait could be a target for rehabilitation for pwCMT. Perceived fatigue did not correlate to gait fatigue, underscoring the differentiation between perceived fatigue and performance fatigability.