Visual and proprioceptive contributions to postural control of upright stance in unilateral vestibulopathy

Katrin Eysel-Gosepath,Christopher Mccrum,Gaspar Epro,Gert-Peter Brüggemann,Kiros Karamanidis

doi:10.1080/08990220.2016.1178635

Abstract

Preserving upright stance requires central integration of the sensory systems and appropriate motor output from the neuromuscular system to keep the centre of pressure (COP) within the base of support. Unilateral peripheral vestibular disorder (UPVD) causes diminished stance stability. The aim of this study was to determine the limits of stability and to examine the contribution of multiple sensory systems to upright standing in UPVD patients and healthy subjects. We hypothesized that closure of the eyes and Achilles tendon vibration during upright stance will augment the postural sway in UPVD patients more than in healthy subjects. Seventeen UPVD patients and 17 healthy subjects performed six tasks on a force plate: forwards and backwards leaning, to determine limits of stability, and upright standing with and without Achilles tendon vibration, each with eyes open and closed (with blackout glasses). The COP displacement of the patients was significantly greater in the vibration tasks than the controls and came closer to the posterior base of support boundary than the controls in all tasks. Achilles tendon vibration led to a distinctly more backward sway in both subject groups. Five of the patients could not complete the eyes closed with vibration task. Due to the greater reduction in stance stability when the proprioceptive, compared with the visual, sensory system was disturbed, we suggest that proprioception may be more important for maintaining upright stance than vision. UPVD patients, in particular, showed more difficulty in controlling postural stability in the posterior direction with visual and proprioceptive sensory disturbance.

Highlights

The human ability to effectively control posture is the result of accurate function and interplay of the central nervous system and the musculoskeletal system
It was hypothesized that the absence of visual information and disturbance of the proprioceptive systems would increase the postural sway in patients with unilateral peripheral vestibular disorders (UPVD) to a greater extent than in healthy subjects, thereby revealing reduced balance maintenance ability in the patients
It was hypothesized that disturbance of visual and proprioceptive systems would increase the postural sway in patients with UPVD to a greater extent than in healthy subjects, thereby revealing a reduced balance maintenance ability in the patients

Summary

Introduction

The human ability to effectively control posture is the result of accurate function and interplay of the central nervous system and the musculoskeletal system. It was hypothesized that the absence of visual information and disturbance of the proprioceptive systems would increase the postural sway in patients with UPVD to a greater extent than in healthy subjects, thereby revealing reduced balance maintenance ability in the patients Such findings could enhance our understanding of the role of the visual system and the triceps surae muscle spindles in postural control during functional motor tasks in vestibulopathy patients, as knowledge of the compensation of the sensory systems in such patients may aid in the design of rehabilitative programmes to encourage such compensation

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