The influence of age on the maintenance of frontal plane dynamic stability

The influence of age on the maintenance of frontal plane dynamic stability Christopher P. Hurt Department of Movement Sciences University of Illinois at Chicago Chicago, Illinois (2012) Dissertation Chairperson: Mark D. Grabiner Compared to forward or backward-directed falls, laterally-directed falls significantly increase the risk of hip fracture by older adults. The long-term goals of this work are to identify modifiable risk factors for laterally-directed falls by older adults and, subsequently, to design and evaluate clinical interventions targeting these risk factors. Currently however, it is unknown how laterally-directed falls are initiated. It is possible that with age the ability to regulate frontal plane center of mass motion with respect to the base of support is compromised. A series of studies was conducted to investigate the age-related effects of age on the maintenance of dynamic stability during tasks that are potentially destabilizing in the frontal plane. The tasks included: normal walking, laterally-directed disturbances delivered by a motorized platform to standing subject, and laterally-directed disturbances to dynamic stability resulting from subjects performing voluntary laterally-directed steps during forward-directed walking. The results of these studies suggest that the ability of older adults to maintain frontal plane dynamic stability is context specific. Previously reported frontal plane instability of older adults recovering from disturbances delivered to standing posture may not relate to the ability of older adults to maintain frontal plane dynamic stability during dynamic mobility-related tasks. This potential context dependency is of clinical importance. These results can inform the development of clinical interventions that target risk factors related to frontal plane dynamic instability and ultimately laterally-directed falls.