Like riding a bike: Machine helps muscles ‘come alive’
About six weeks ago, Mary Kraft couldn’t walk without assistance. Today, she can “ride a bike”” down miles of simulated highway toward the gleaming, digital Minneapolis skyline.
Kraft is the first patient at Fairview’s Acute Rehabiliation Center to use an RT300 therapy machine, a new piece of equipment that stimulates muscles of stroke patients and those with spinal cord injuries.
A great 'awakening'
Earlier this winter, a battle with influenza and steroid myopathy (in which muscle fibers atrophy and muscles weaken) left Kraft, 60, weak and unable to walk without assistance.
The effects were exaggerated because a stroke she had about five years ago left her more prone to the debilitating effects of illness.
Kraft vividly remembers the first time she tried the therapy machine on her arms.
“It woke my whole arm up,” she says. “My whole arm, my wrist, my hand all came alive. I was so tickled."
Kraft’s stay at the center lasted about a month, during which she used the RT300 four times, on her arms and her legs.
“Now, I can walk farther, and it feels better,” she says. “Your muscles forget how to do this. I wish I would’ve had this set-up when I first had my stroke. I’m impressed.”
Patient Mary Kraft shows how the therapy cycling machine works in this short video
Creating a workaround for your brain
The therapy machine, which is located in the Acute Rehabilitation Center at University of Minnesota Medical Center – West Bank, is the first such equipment at Fairview and can be used for arms or legs.
It looks like a regular workout bike, with the addition of electrodes that attach to the rider’s arms, legs, back and torso to deliver electric stimulation to help fire muscles in the right pattern, mimicking the subconscious way a person would ride a bike.
The strength of the stimulation can be adjusted, depending on the rider’s tolerance and muscle fitness.
Stimulation can even be increased or decreased separately for each limb, if a person’s mobility differs that way (say, for example, if a stroke has weakened only one side).
“What’s special about this machine is that someone who had a complete spinal injury could ride it. Christopher Reeve could’ve ridden this,” says Sharon Kimble, physical therapist, referring to the late actor who was paralyzed in an accident.
“This bike stimulates nerves from a different source, bypassing the part of the system that is damaged.”
Riders watch a small screen that shows an illustrated “street” and try to stay on the white line in the middle, indicating they’re using the same amount of muscle energy on each side of their body. A cityscape looms on the horizon to encourage riders to keep going.
“I keep thinking I’m going to get closer to Minneapolis—knowing I’m not, of course!” Kraft jokes as she finishes a recent 4.5-mile ride.
Brain cells ‘just waiting for a job’
Spinal cord injuries or a stroke can interrupt the brain’s connections to the muscles.
Regularly stimulating muscles after a stroke can help build plasticity—which is when certain brain cells take on new roles and replace those that have been damaged—and build muscle and cardiac fitness, even in the absence of neurological controls.
“We have so many brain cells just waiting for a job, collecting dust,” Kimble says.
“Stimulation like this helps redirect cells’ purposes in the area of the head injury, which will improve muscle function and activity. That’s why it’s important to keep muscles moving, even when the brain can’t directly communicate with them.”