A strange new treadmill is being investigated at the Kennedy Krieger Institute in Maryland to help rewire the brains of stroke victims and others with brain injuries.
The split-belt treadmill is “a fascinating concept,” says Dr. Milton Thomas of the Baylor Institute for Rehabilitation, who was amazed that Bastian’s [Amy Bastian, MD at Kennedy Krieger Institute] experiments didn’t have people falling down. The research “showed both legs are taught to function almost independent of each other — or can be.”
First, Bastian tested the funky walking on 40 healthy people. Sometimes, the treadmill moved their legs in opposite directions. Sometimes it moved one leg up to four times faster than the other.
With a 15-minute session, she essentially retrained them to walk with a lurch. No matter how hard they tried to walk normally when the session ended, they couldn’t for 10 minutes or so — until automatic nerve systems recalibrated themselves again.
Tracking that adjustment, Bastian reported in the journal Nature Neuroscience last month that there are separate neural networks to control forward walking and backward walking, and each leg, too. That means researchers might target just the bad leg.
What about people with brain injuries? Thirteen stroke survivors who had limped for months saw that same brief improvement from the treadmill test, Bastian and University of Delaware physical therapist Darcy Reisman reported in the journal Brain.
That suggests the right circuitry for good walking is lying dormant in these patients, if doctors can learn to tap it.