Control of Linear Head and Trunk Acceleration During Gait After Unilateral Vestibular Deficits

Objective: To use clinically available inertial measurement units to quantify the control of linear accelerations at the head and trunk during gait in different sensory conditions in individuals with unilateral vestibular loss. Design: Observational study. Setting: Outpatient research laboratory. Participants: Individuals (n=13; mean age, 47.6±13.7y; 69% women) 6 weeks after vestibular schwannoma resection surgery and vestibular healthy participants (n=16; mean age, 29.7±5.9y; 56% women). Intervention: Not applicable. Main Outcome Measures: Walking speed normalized, root mean square values of cranial-caudal, medial-lateral, and anterior-posterior directed linear accelerations at the head and the trunk while walking in 2 visual sensory conditions (eyes open and eyes closed). Results: Linear mixed models for each root mean square value were fit on the effects of group, condition, and group by condition. The group by condition effect was used to examine the primary hypothesis that individuals with vestibular loss would experience greater change in triplanar root mean square values at the head and trunk from the eyes open to eyes closed condition compared with the vestibular healthy group. The group by condition effect was found to be significant at the head in the cranial-caudal (β=0.39; P=.002), medial-lateral (β=0.41; P<.001), and anterior-posterior (β=0.43; P<.001) directions. The group by condition effect was also significant in the cranial-caudal (β=0.39; P=.002), medial-lateral (β=0.39; P<.001), and anterior-posterior (β=0.23; P=.002) directions at the trunk. Conclusions: Participants who underwent vestibular schwannoma resection were more impaired in their ability to control accelerations at the head and trunk without visual sensory information than vestibular healthy participants. These impairments were detectable using clinically available inertial measurement units.