MOTOR FATIGABILITY DURING A RUNNING PROTOCOL IN HIGHLY FUNCTIONAL INDIVIDUALS WITH MS
Background/Objective: Multiple Sclerosis (MS) is a chronic neurodegenerative disease which presents with various debilitating symptoms, commonly including fatigue-induced gait abnormalities. It is important to understand the underlying mechanisms of motor fatigability in the initial stages of MS to promote earlier access to treatment. The aim of this study was to investigate the effects of a fatiguing running task on ankle kinematics and step length in highly functional people with MS. Methods: This study is a secondary data analysis of existing running data of highly functional MS participants previously collected for the use of a PhD study. Participants in the original study completed a 20-minute treadmill running protocol during which their running parameters were captured by the 3D motion analysis Vicon Nexus system. The present study analysed running data of five participants (3 females and 2 males) with MS (EDSS 1.0-2.5). Paired t-tests were used to identify statistically significant changes (p>0.05) in ankle kinematics and step length, suggesting motor fatigability, from the first to last minute of the running task. Results: Neither ankle kinematics nor step length displayed statistically significant changes from the beginning to end of the 20-minute running protocol in the mildly impaired MS participants. One of the five MS participants displayed a reduction in peak ankle dorsiflexion in swing phase greater than two degrees which was considered clinically significant, presenting an indication of footdrop as an outcome of motor fatigability. Conclusion: Changes in running parameters can be measured during a 20-minute running task in highly functional individuals with MS to analyse signs of motor fatigability. The results of this study have potential clinical implications regarding foot drop in the mildly impaired MS population during running. Further research is required to confirm subclinical markers in highly functional people with MS.