By Emily Delzell
Chronic stroke patients who can walk independently but retain gait deficits experience greater gains in both walking speed and quality with an overground walking intervention than with body-weight supported treadmill training (BWSTT), according to results of a pilot study epublished by Clinical Rehabilitation in February.
Physical therapists at the University of Indianapolis randomized 18 participants who were at least six months poststroke and could walk 10 m at a self-selected speed of less than 1 m/s to two weeks of BWSTT or overground walking. Each group walked 30 minutes per session, five days a week, and maintained a moderately intense pace.
Investigators measured participants’ walking speed and endurance, spatiotemporal symmetry (step length, stance time, and swing time), and self-reported limitations in activity and community participation at baseline, within a week of the intervention’s end, and at three months.
Participants walked overground on a flat indoor track while investigators verbally coached them on gait pattern characteristics. Those in the BWSTT group began training with 30% of total body weight unloaded and received both verbal and manual cueing; investigators reduced body-weight support to 15% and then 0% after participants reached specified speed and endurance thresholds. Sixty percent of these patients ultimately achieved 0% support.
Patients in the overground group had larger statistically significant improvements in comfortable walking speed than the BWSTT group a week after the intervention (change of .11 m/s vs .06 m/s, respectively) and at three months (change of .14 m/s vs .08 m/s, respectively). The overground group also had statistically significant improvements from baseline in swing time symmetry immediately postintervention and at three months. Self-reported activity improved significantly in both groups just after intervention, but patients didn’t retain those gains at three months, and neither group showed any significant improvement in participation.
“While there were not that many differences between the groups, where there were differences, they were in support of the overground group,” said study lead author Stephanie Combs-Miller, PT, PhD, NCS, associate professor of physical therapy. “This supports the idea that we can do therapy with no equipment if we do it in the right way—if we set the correct parameters and we think about our dosage and make it intense, we can get very similar if not better outcomes.”
She speculated that patients in the BWSTT group, who received almost constant manual correction, became dependent on therapists for direction, while the overground group learned to self-adjust, an approach that translated better to real-world walking.
Combs-Miller said she was disappointed in the lack of improvement in patients’ community participation and activity, which, she noted, is the ultimate goal of stroke rehabilitation. She and her colleagues are now studying an alternate intervention specifically aimed at increasing community participation and activity.
“We’re using a similar thirty-minute intervention, but we’re walking patients around our campus over different surfaces, including grass, gravel, concrete, and mulch, up and down ramps, and through traffic intersections, to see if learning to deal with these barriers makes them more likely to feel like they can participate in the community—and we’re seeing that this does make the difference,” she said.
Michael Lewek, PT, PhD, associate professor of physical therapy at University of North Carolina at Chapel Hill, said the changes in gait speed, while significant and in line with results seen in his lab and reported elsewhere, and the duration of the intervention may not have been sufficient to alter community participation.
He agreed that stroke patients need to walk in a variety of environments to successfully re-enter their communities.
“In our lab we routinely have them do stairs, ramps, curves, and uneven surfaces,” he said.
Lewek’s lab also avoids using BWSTT and manual cueing.
“Our data don’t support offloading body weight in ambulatory patients,” he said. “And we rely on verbal rather than manual cueing because we feel it’s better for the patient to make an extra effort themselves. Our gait patterns don’t look normal, but I’d rather them have do the work and walk with an imperfect gait pattern than have them walk with a perfect gait pattern and have me do all the work.”
Combs-Miller SA, Kalpathi Parameswaran A, Colburn D, et al. Body weight-supported treadmill training vs. overground walking training for persons with chronic stroke: A pilot randomized controlled trial. Clin Rehabil 2014 Feb 11. [Epub ahead of print]