MOTOR FATIGABILITY DURING A RUNNING PROTOCOL IN HIGHLY FUNCTIONAL INDIVIDUALS WITH MS
Abstract
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.