Grant: Discovery Grants Program - Individual

BACKGROUND: Muscle strength, balance, and mobility decline with aging, contributing to loss of functional independence and inability to continue living independently. As the Canadian population ages, staggering costs will be imposed on our economy and health care system, as the need for hospitalization, in-home care, and long-term care increases. Understanding age-related changes in human function, movement, and balance is more crucial than ever before. Biomechanical signals (i.e., neuromuscular, kinematic, or balance signals) provide insight into how movement is produced and controlled, and relate to falls, pain, and injury. Measures from these signals differ between younger and older adults during tasks such as quiet standing. However, these studies often focus on one biomechanical aspect of movement or several aspects independently; integrating aspects would provide further insight into changes in the organization and control of movement with healthy aging. These changes will be explored using discrete volitional tasks (e.g., lifting, standing from a chair), as these tasks are common in everyday life and relate to fall risk in older adults. OBJECTIVES: This research will explore age-related changes in movement structure, organization, and variability during discrete volitional tasks, using an integrated biomechanical approach. Age-related changes in these tasks will be examined in terms of 1) movement strategies, 2) relationships between biomechanical signals, and 3) relationships in the variability of these signals. METHODS: Younger and older adults with no diagnosed conditions affecting balance or mobility will perform discrete volitional tasks while whole-body motion, ground reaction forces, and muscle activation are measured using motion capture, force plates, and electromyography, respectively. Various aspects of movement structure and organization will be examined, using principal component analysis; cross-correlation of biomechanical signals; and cross-correlation of time-varying variability of biomechanical signals. Relationships between outcomes, and age-related differences in outcomes, will then be explored. IMPACT: The proposed integrated biomechanical approach will provide insight into markers of declining human function during healthy aging, as well as a foundation for a mechanistic model of the aging process. Such a model will explore age-related changes in movement structure, organization, and variability and their underlying mechanisms, improving our understanding of healthy aging. This program will also contribute to strategies to promote function and longevity, which will enable older adults to maintain independence in everyday life. With our aging Canadian population, the knowledge and strategies that will be generated from this research are more crucial than ever before, to reduce the enormous societal costs of older adult care, and to help older adults maintain independence and quality of life.