Wearable technology reveals gait compensations, unstable walking patterns and fatigue in people with multiple sclerosis

Objective: People with multiple sclerosis (PwMS) often experience a dedine in gait performance, which can compromise their independence and increase falls. Ankle joint contractures in PWMS are common and often result in compensatory gait patterns to accommodate reduced ankle range of motion (ROM). Approach: Using advances in wearable technology, the aim of this study was to quantify head and pelvis movement patterns that occur in PwMS with disability and determine how these secondary gait compensations impact on gait stability. Twelve healthy participants and 12 PwMS participated in the study. Head and pelvis movements were measured using two tri-axial accelerometers. Measures of gait compensation, mobility, variability, asymmetry, stability and fatigue were assessed during a 6 min walking test. Main results: Compared to healthy controls, PwMS had greater vertical asymmetry in their head and pelvic movements (Cohen's d = 1.85 and 1.60). Lower harmonic ratios indicated that PwMS were more unstable than controls (Cohen's d = -1.61 to -3.06), even after adjusting for their slower walking speeds. In the PWMS, increased compensatory movements were correlated with reduced ankle active ROM (r = -0.71), higher disability (EDSS) scores (r = 0.58), unstable gait (r = -0.76), reduced mobility (r = -0.76) and increased variability (r = 0.83). Significance: Wearable device technology provides an efficient and reliable way to screen for excessive compensatory movements often present in PWMS and provides clinically important information that impacts on mobility, stride time variability and gait stability. This information may help clinicians identify PWMS at high risk of falling and develop better rehabilitation interventions that, in addition to improving mobility, may help target the underlying causes of unstable gait.