Vestibular and neck muscle contributions to head control in response to induced head perturbations and falls in balance-impaired older adults

University Of Kansas Medical Center, Kansas City KS

Investigators

Abstract

PROJECT SUMMARY/ABSTRACT Falls are common in older adults, and head (including face) and neck injuries are common and result in significant morbidity. Yet, little is known about the mechanisms of control of the head and neck during a fall and few interventions are directed toward limiting these injuries. This high risk/high reward approach is fundamentally different from traditional approaches and measures head motion during lab-based falls in older adults at risk for fall-related injury. We will leverage our experience of collecting fall impact data in older adult participants to maximize safety in the current proposal. The ultimate goal of this innovative proposal is to set the stage for the development of a novel approach(es) to reduce fall related head/neck injuries in older adults. The current proposal seeks to determine whether motor or vestibular function and/or their combination contribute to head control during falls. Our expert research team utilizing state-of the art assessments will explore whether the vestibular system, specifically the sacculo-collic reflex (due to role in modulating reflexive adjustments of the musculature in the neck) and/or neck mechanics (muscle strength, range of motion and muscle activation) are related to head control during a fall. A secondary aim will explore relation between head motion following laboratory-based head pull perturbation and head motion during a fall and if it is modified by neck mechanics. Lastly, other potential factors such as arm use, gender, and abnormal balance/gait will also be explored. A total of 30 older adults (> 65 years of age) with balance impairment, and with varying vestibular function will be enrolled. Participants will undergo a series of standardized tests including comprehensive vestibular assessments, neck mechanics assessment and backward and sideway falls. During all of the tests, head motion and neck muscle activity will be quantified utilizing validated techniques. Studying the links between vestibular function, neck mechanics, and head control in an actual fall provides a better understanding of the mechanisms contributing to head and neck injury and eventually points to better-directed therapies to decrease this injury risk. Preliminary data from this high risk/high reward project will direct larger, more appropriately powered and more definitive testing of the mechanisms underlaying head control during falls.