People who have suffered paralyzing injuries sometimes can regain limited control of their muscles, thanks to electrical stimulation techniques now under development, but pulse patterns should be varied to help patients stay strong longer, University of Delaware researchers report in the new Journal of Neurophysiology.
This finding, described in the journal's April 1998 issue, may suggest a better way to stimulate the muscles of people with paralysis, says Stuart A. Binder-Macleod, associate chairperson of UD's Department of Physical Therapy, a top 10 national program, according to U.S. News & World Report.
"Patients can move their muscles much more forcefully for a longer period of time if their muscles are stimulated at varying rather than regular intervals," Binder-Macleod says. "This study is the first to show the effectiveness of a variable pulse pattern, and it's very exciting."
For people like "Superman" actor Christopher Reeve, who in 1995 broke several upper cervical vertebrae in a Virginia steeplechase accident, the prognosis traditionally has been poor, Binder-Macleod notes. Unfortunately, he says, such devastating accidents are not uncommon. Binder-Macleod and his UD colleagues say they hope that such tragedies someday can be reversed--at least in part--through artificial stimulation of skeletal muscles.
But first, he says, researchers must find a way to maintain the strength of artificially stimulated muscles, which tend to become progressively fatigued in response to small electrical shocks.
Mimicking the central nervous system
"When a person's central nervous system 'turns on' a muscle, it uses an
irregular pattern of pulses during activation," says Binder-Macleod, whose
research team included doctoral student Samuel C.K. Lee and undergraduates April
D. Fritz and Lorin J. Kucharski. "A similarly varied pulse pattern may prove
useful in c
Contact: Ginger Pinholster
University of Delaware