Impaired spatiotemporal gait parameters in patients with unilateral and bilateral vestibular deficits

Gait requires the coordination of various sensory systems, especially the vestibular system. Vestibular deficits can induce postural instability and gait disorders due to the failure of vestibular reflexes which stabilize the gaze, the head, and the body [1]. Chronic imbalance is among the main complaints of patients with bilateral vestibulopathy and causes a high risk of falls [2]. However, there is very limited quantitative data on the functional impact of vestibular deficits on gait patterns. Do spatiotemporal parameters during walking at different speeds differ significantly between individuals with vestibulopathy and healthy subjects? The study included 30 participants, consisting of 10 patients diagnosed with bilateral vestibulopathy (BV) (5 female; 64.4 ± 9.6 years), 10 patients with unilateral vestibulopathy (UV) (5 female; 63.4 ± 6.2 years), and 10 healthy subjects (HS) (6 female; 64.6 ± 10.0 years). To track body movements, the 3-dimensional trajectories of 35 reflective markers were recorded using 12 optoelectronic cameras (Oqus7+, Qualisys). Gait trials were conducted at various walking speeds: comfortable, slow, and fast paces. Dimensionless [3] spatiotemporal parameters were calculated from these recordings to study the differences in the walking pattern between groups. A mixed-model repeated measures analysis of variance was performed to statistically compare the parameters of interest between participants of the control (HS) and pathological groups (UV, BV). To control the false discovery rate p values were adjusted with a classical one-stage method. The main results are presented below and in Fig. 1. The left side was randomly selected for the analysis. BV and UV showed a significantly lower dimensionless walking speed (mean±sd at comfortable walking speed; BV = 0.36 ± 0.08; UV = 0.35 ± 0.06; HS = 0.43 ± 0.04) and dimensionless step lengths (mean±sd at comfortable walking speed; BV = 0.63 ± 0.12; UV = 0.64 ± 0.13; HS = 0.75 ± 0.06) than HS for all walking speeds. Step widths in meter and double support time in gait cycle percentage were also significantly different for pathological groups compared to HS at comfortable and slow speeds. These differences disappeared at fast walking speeds.Download : Download high-res image (212KB)Download : Download full-size image These findings indicate that some gait parameters are impaired in patients with vestibular deficits. Greater step width observed in patients could be explained by the search for greater stability. Moreover, it was reported that patients with vestibular deficits show better balance at higher walking speeds [4] which could explain the results of some spatiotemporal data that did not show significant differences between patient groups and HS (Step width, Double support time). We observed a large variability in the data among the pathological groups. Therefore, it might be interesting to study the variability of walking and kinematics more specifically to show the differences between these groups.