Development of Clinical Methods to Evaluate Neural Function in Aging

Study Summary

A primary focus of the University of Florida (UF) Claude D. Pepper Older Americans Independence Center (OAIC) is to build a comprehensive understanding of the causes and consequences of declining physical function and disability development among older adults. To date investigators have largely focused on sarcopenia, the age-related decline in skeletal muscle mass and strength, as the primary contributor to physical decline. However, recent findings indicate that changes in the central and/or peripheral nervous systems may play a larger role than previously thought in the development of functional limitations. These fields hold extensive promise for identifying novel contributors to age-related functional decline. Therefore, the overarching aim of this project is to develop the ability of RC1 to assess novel neural contributors to mobility and overall physical function. Importantly, the development of these techniques will provide the RC1 with the tools to evaluate the potential involvement of the central and peripheral nervous systems in age-related functional decline and disablement. The primary aim of this project is to develop techniques for quantifying peripheral motor unit number and size as well as spinal cord integrity.

Primary Outcome

Tasks that require prolonged muscle force are carried out by slow, fatigue-resistant motor units, while tasks that require a quick but short increase in muscle force are mostly performed by fast motor units. Many of the postural muscles have a large proportion of S motor units. On the other hand, muscles that participate in quick limb movements such as kicking, hitting, or catching typically have a large proportion of FR and FF motor units. Most muscles, however, have a relatively wide range of

Interventions

• OTHER High-functioning older adults
• OTHER Lower-functioning older adults
• OTHER Young adults