Walking fatigability and coordination in persons with MS during a seated rhythmical bipedal coordination task

Abstract

Background: Coordination is possibly affected in persons with MS (PwMS). A worse coordination could cause an increased energy cost similar to walking at a slower or faster pace. It is not known if coordination has an impact on fatigue. It would be interesting to see if there is a link between coordination and fatigue as it is one of the most common symptoms in PwMS. Methods: PwMS and Healthy controls (HC) were asked to perform a 6 minute walking test to determine walking fatigability. All subjects then performed a coordination task where they had to synchronize their legs, with a metronome at three different paces (0.75 Hz; 1 Hz; 1.5 Hz). The motion occurred only in the sagittal plane around the knee joint and was maintained for 1 minute for each pace. Analysis of the phase, standard deviation (SD), coefficient of variability (CoV), Absolute error (AE) and Phase coordination index (PCI) was done by mixed models in Jmp pro 14. Results: All subjects (13 HC and 36 PwMS) had an increased SD, CoV and PCI for the 0.75 Hz condition compared to 1Hz and 1.5 Hz. PwMS performed worse compared to HC. No differences were observed between PwMS with fatigability and PwMS without fatigability. Discussion and conclusion: Coordination is worse for both HC and PwMS at slower speed, but not at faster speed. PwMS have a worsened coordination than HC for all the conditions on top of the normal worsening seen in HC. Important keywords: Multiple Sclerosis, Fatigability, Interlimb coordination