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—even if the skyline never gets any closer.
Mary was the first patient at Fairview’s Acute Rehab Center on University of Minnesota Medical Center – West Bank, to use an RT300 therapy machine, a new piece of equipment designed to stimulate muscles of stroke patients and those with spinal cord injuries or stroke.
Earlier this winter, a battle with influenza and steroid myopathy (in which muscle fibers atrophy and muscles weaken) left Mary, 60, weak and unable to walk without assistance. The effects were exaggerated because she had a stroke about five years ago, leaving her more prone to muscle issues.
Mary vividly remembers the first time she tried the RT300 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.”
Mary’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,” Mary 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.”
The Acute Rehab Center’s RT300 machine is the first in the Fairview system. It can be used for arms or legs.
It looks like a regular workout bike, but it’s so much more. Electrodes attach to the rider’s arms, legs, back and torso to deliver electric stimulation, which helps 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 level of mobility. Stimulation can even be strengthened or weakened 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. “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!” Mary joked as she finished a recent 4.5-mile ride.
Spinal cord injuries or a stroke can interrupt the brain’s connections to the muscles. Regularly stimulating muscles can help build plasticity, which is when certain muscle cells take on new roles and replace those that have been damaged.
“We have so many brain cells just waiting for a job, collecting dust,” Sharon says. “Stimulation like this can redirect them to areas that need them and help reverse atrophy. That’s why it’s important to keep muscles moving, even when the brain can’t directly communicate with them.”