New evidence shows a direct link between brain function and muscle strength in human body, according to researchers at the Ohio University Heritage College of Osteopathic Medicine.
The researchers have found that mental imagery exercises can prevent muscles from getting weaker after not being used for extended periods of time, which can help to treat patients undergoing neurorehabilitation, especially after a stroke.
The finding also offers new evidence about the role of the nervous system in muscle weakness. Though imagery techniques are used by professional athletes, this is the first study to show that imagery can play a role in stopping or slowing the loss of muscle strength following prolonged disuse.
In their experiment, they studied participants who had one arm immobilized in a cast for a month and they were asked to perform imagery exercises five times a week. In the exercise, researchers told participants to relax their forearm muscles and then imagine contracting their muscles and flexing their wrist. Researchers recorded participants’ muscle activity using an electromyogram (EMG).
Brian Clark, professor of physiology and neuroscience at the Heritage College and executive director of the Ohio Musculoskeletal and Neurological Institute (OMNI), said “What our study suggests is that imagery exercises could be a valuable tool to prevent or slow muscles from becoming weaker when a health problem limits or restricts a person’s mobility.”
“The most impactful finding, however, is not the direct clinical application but the support that this work provides for us to better understand the critical importance of the brain in regulating muscle strength. This information may fundamentally change how we think about muscle weakness in the elderly,” he added.
scientists have long known that the brain’s cortex helps coordinate and control muscle movement, but there was controversy about the link between the cortex and muscle strength.
Clark describes muscles as the puppets of the nervous system and it is the brain that makes muscles move. “We wanted to tease out the underlying physiology between the nervous system and muscles to better understand the brain’s role in muscle weakness,” said Clark.
Besdies Clark, other researchers who helped in the study are Niladri Mahato, Masato Nakazawa, Timothy Law, and James Thomas. The results from the study were published in the Journal of Neurophysiology.
Clark will be conducting additional research on muscle strength loss in an upcoming four-year project funded by the National Institutes of Health’s (NIH) National Institute on Aging. The study, “Unraveling the Neural Contributions of Dynapenia in Elders” (The UNCODE Study), will use noninvasive techniques to better understand the connection between the brain, nervous system and muscles in the elderly.
The study was funded by the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development.