Treadmill study helps participants' mobility one step at a time

by Tom Tozer

It is a common assumption that it takes years to realize any measurable benefits from scientific research. It's a marvel, therefore, to see an almost immediate payoff: a dramatic upturn in a person's quality of life.

Following a plane crash, Jim Harris didn't walk for two years. Today, with effort, he is walking. After a terrible fall, Bob Moody could only be on his feet for a couple of minutes. Now he's taking 20-minute walks. As the result of a horrible automobile accident, Janette Rodgers was told she'd never walk again and was nearly taken off life support. Now she's walking and improving her speed.

These recoveries and subsequent improvements have been possible, in no small part, because Sandra Stevens, a physical therapist, put these people through their paces on an underwater treadmill inside a fiberglass tank that holds 270 gallons of water—all part of her doctoral research at MTSU. Her research subjects all have suffered severe spinal-cord trauma.

Previously, graduate students in MTSU's exercise science program utilized the underwater treadmill to help children with cerebral palsy increase their muscle strength and improve mobility. The results were encouraging.

"It's relatively new technology," said Dr. Don Morgan, health and human performance professor, who first brought the treadmill to MTSU several years ago. "It's been used by athletic teams and for older folks with arthritis. But it had never been used with children with CP."

Morgan and his students began their initial work with the underwater treadmill thanks to funding from the National Institutes of Health.

"After watching the kids with cerebral palsy, I thought there were a lot of other populations that could benefit from this kind of therapy," Stevens said.

Stevens worked with Rodgers, Harris, Moody and others for eight weeks during the fall semester, meeting with each two or three times a week.

"I looked at leg strength, balance, daily walking behavior, walking speed and endurance," Stevens said. "Some of these folks could only walk for a minute, then they would have to sit. When they started walking in the tank, the minimum time I set was five minutes of walking. They all were able to do that."

Walking in water is ideal for people with spinal-cord injuries because they have a blunted cardiovascular response to any exercise, Stevens explained, adding that the nerves that trigger the heart to beat faster are also the nerves that trigger walking. The low muscle tone in their legs and their inability to increase their heart rate resulted in very poor endurance, creating a repetitive and nonproductive cycle. Walking in water produces greater blood flow, which increases cardiovascular activity, she said.

"They experience a real psychological boost," Stevens said. "At first they feel like they're in the way. After trying initially [to walk], they say, 'What's the point? I won't be able to walk anyway.'"

Toward the end of the study, Stevens said her volunteers were walking up to four trials at eight minutes each. "So they've gone from four or five minutes of walking to 32 or 34 minutes. That's a big improvement."

When Moody started, he was walking at 1.5 miles an hour in the tank. Now he's up to 2.5 miles an hour, which is just about a normal gait pattern, Stevens said.

Harris started at .33 miles an hour, and "he's over a mile per hour now, so he's more than tripled his speed. É Jim (also) was not able to stand independently at all. Now he can stand alone for almost a minute without holding onto anything," she said.

Rodgers went from a wheelchair to a walker with a seat, "so she can push it or sit down and scoot or have somebody push her," Stevens said. "She's doing great at walking in the tank. It's pretty exciting."

Stevens said she has given each participant an exercise regimen that they can continue at home.

"I think as they gain confidence, they're changing how they do everything in their daily life. As they challenge themselves everyday, it contributes to their improvement," she said.

In addition to serving as an adjunct instructor in exercise science at MTSU, Stevens is a temporary faculty member at Tennessee State University in the College of Health Science.

She earned her bachelor's degree at the University of Kansas and a Master of Science degree at MTSU. She is continuing her research project this spring and hopes to complete her doctorate in human performance this summer.


From the Jan. 25, 2010 edition of The Record Vol. 18/No. 14.