Evaluating Test-Retest Reliability of Fatigability in Chronic Stroke

Area of Science:

• Neurology
• Rehabilitation Medicine
• Exercise Physiology

Background:

• Post-stroke fatigue is subjectively reported, leading to variable prevalence rates.
• Objective measures of performance fatigue may provide a more consistent assessment of fatigue in stroke survivors.

Purpose of the Study:

• To determine the test-retest reliability of fatigability measured during the 6-minute walk (6MW) test in individuals with hemiparetic stroke.
• To explore the relationships between stroke-related fatigability and other functional and physiological measures.

Main Methods:

• Twenty-three hemiparetic stroke survivors completed two 6MW tests at least 48 hours apart.
• Fatigability was calculated as the ratio of change in walking speed to distance covered during the 6MW.
• Measurements included oxygen consumption (VO2), peak aerobic capacity (VO2peak), walking speed, Dynamic Gait Index (DGI), and subjective fatigue.

Main Results:

• Fatigability demonstrated high test-retest reliability (ICC = 0.99, p < 0.001) with no significant difference between trials.
• Strong correlations were found between fatigability and 6MW oxygen consumption (VO2) (r = 0.92-0.95, p < 0.001).
• Moderate-to-strong relationships were observed between fatigability and various walking speeds, VO2peak, and DGI (r = -0.47 to -0.82, p < 0.001).

Conclusions:

• The 6MW test provides a reliable and objective method for assessing fatigability in stroke survivors.
• Fatigability is closely linked to functional mobility and aerobic capacity in this population, offering insights into underlying contributors.