Postural compensation strategy depends on the severity of vestibular damage

• Main Authors: Lara A. Thompson, Csilla Haburcakova, Richard F. Lewis
• Format: Article
• Language: English
• Published: Elsevier 2017-03-01
• Series: Heliyon
• Subjects: Health sciences; Biomedical engineering; Physiology
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405844016321776

The purpose of this study was to investigate the effects of various levels of vestibular function on balance in two, free-standing rhesus monkeys. We hypothesized that postural control strategy depended on the severity of vestibular damage. More specifically, that increased muscle stiffness (via short-latency mechanisms) was adequate to compensate for mild damage, but long-latency mechanisms must be utilized for more severe vestibular damage. One animal was studied for pre-ablated and mild vestibular dysfunction states, while a second animal was studied in a pre-ablated and severe vestibular dysfunction state. The vestibulo-ocular reflex (VOR), an eye movement reflex directly linked to vestibular function, was used to quantify the level of vestibular damage. A postural feedback controller model, previously only used for human studies, was modified to interpret non-human primate postural responses (differences observed in the measured trunk roll) for these three levels of vestibular function. By implementing a feedback controller model, we were able to further interpret our empirical findings and model results were consistent with our above hypothesis. This study establishes a baseline for future studies of non-human primate posture.