March 27, 2007

By Frank Long

A new research project that focuses on motor-control mechanisms in the elderly may provide a better understanding of communication between neurons and muscles, and how fast-twitch muscle response might be preserved among older populations.

The National Institutes of Health is sponsoring a study by University of Delaware researcher, Christopher Knight, who says slowed physical responses contribute to more falls as people age.

“You need fast movement to prevent a fall,” Knight says. The researcher has been examining muscular force with an experimental device that records the time it takes for a muscle command to travel from a neuron to muscle fiber.

Results of Knight’s studies have shown lower firing rates between neurons and muscle fiber in older subjects compared to the firing rates in younger subjects, indicating a diminished ability in muscle response among the older test participants.

Knight says he believes his work will provide value in understanding motor-control mechanisms in general and impaired control in patient populations.

The ultimate goal of the research, Knight says, is to improve movement quality in older adults, as well as patients with disorders such as cerebral palsy or multiple sclerosis, or who are recovering from strokes.

The loss of fast-twitch muscle fibers through the aging process can be combated, according to Knight, who says power training with weights produces an increase in firing rates. “For safety, we’re commonly advised to do things slowly when exercising, but it’s important to also do some fast exercises,” Knight says.

“Even in the frail elderly it is possible to use exercise bands for manual resistance to improve the speed of movement,” he adds.