Objective assessment of motor fatigue in multiple sclerosis using kinematic gait analysis: a pilot study

Abstract

BackgroundFatigue is a frequent and serious symptom in patients with Multiple Sclerosis (MS). However, to date there are only few methods for the objective assessment of fatigue. The aim of this study was to develop a method for the objective assessment of motor fatigue using kinematic gait analysis based on treadmill walking and an infrared-guided system.Patients and methodsFourteen patients with clinically definite MS participated in this study. Fatigue was defined according to the Fatigue Scale for Motor and Cognition (FSMC). Patients underwent a physical exertion test involving walking at their pre-determined patient-specific preferred walking speed until they reached complete exhaustion. Gait was recorded using a video camera, a three line-scanning camera system with 11 infrared sensors. Step length, width and height, maximum circumduction with the right and left leg, maximum knee flexion angle of the right and left leg, and trunk sway were measured and compared using paired t-tests (α = 0.005). In addition, variability in these parameters during one-minute intervals was examined. The fatigue index was defined as the number of significant mean and SD changes from the beginning to the end of the exertion test relative to the total number of gait kinematic parameters.ResultsClearly, for some patients the mean gait parameters were more affected than the variability of their movements while other patients had smaller differences in mean gait parameters with greater increases in variability. Finally, for other patients gait changes with physical exertion manifested both in changes in mean gait parameters and in altered variability. The variability and fatigue indices correlated significantly with the motoric but not with the cognitive dimension of the FSMC score (R = -0.602 and R = -0.592, respectively; P < 0.026).ConclusionsChanges in gait patterns following a physical exertion test in patients with MS suffering from motor fatigue can be measured objectively. These changes in gait patterns can be described using the motor fatigue index and represent an objective measure to assess motor fatigue in MS patients. The results of this study have important implications for the assessments and treatment evaluations of fatigue in MS.

Fatigue induced changes to kinematic and kinetic gait parameters following six minutes of walking in people with multiple sclerosis

“…A few studies have investigated the effects of walking-induced fatigue on the variability of gait kinematics in people with MS. Crenshaw et al found no change in kinematic or kinetic variability following a fatiguing walk in 20 people with MS [17], while a pilot study by Sehle et al reported some increased kinematic variability in individual patients following walking at preferred speed to the point of exhaustion on a treadmill [18]. It is unclear whether these inconsistent findings in kinematic variability might be due to differences in the distance walked, as these were not documented in either study.…”

Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis

“…Within this framework, Sehle et al 26 as well as Phan-Ba et al 11 proposed calculation methods for quantifying the magnitude of walking-related motor fatigue in PwMS during treadmill and overground walking, respectively. The latter study expressed walking speed at the end of the timed 500-m walk test (T500MW) as a fraction of the walking speed obtained from a short walking test (Timed 25-foot Walk Test, T25WT) to derive a deceleration index (DI).…”

Orthotic and therapeutic effect of functional electrical stimulation on fatigue induced gait patterns in people with multiple sclerosis

“…The pattern of knee hyperextension was slightly greater when fatigued with the FES on which may have been done to further compensate for eccentric demands imposed on the knee extensors which are likely to have been weakened further after the fatiguing walk [21]. Poor knee control has been shown to correlate with fatigue [19] and has been shown to deteriorate with walking induced fatigue [18,40]. This avoidance pattern leads to slightly reduced power absorbed at the knee of the more affected limb.…”