High-intensity step training that mimics real-world conditions may better improve walking ability in stroke survivors compared to traditional, low-impact training, according to research.
"People who suffer strokes often have difficulty walking and impaired balance. Rehabilitation after a stroke traditionally focuses on patients practicing low-intensity walking, usually only in a forward direction, which does not provide enough of a challenge to the nervous system to enable patients to negotiate real-world situations, such as uneven surfaces, stairs or changing direction," said study author Dr T George Hornby, professor of physical medicine and rehabilitation at Indiana University School of Medicine in Indianapolis. "Our study suggests that stroke patients can perform higher intensity walking exercises and more difficult tasks than previously thought possible. We need to move beyond traditional, low-intensity rehabilitation to challenge the nervous and cardiovascular systems so patients can improve function and perform better in the real world."
Researchers evaluated 90 people, 18- to 85-years-old with weakness on one side of the body who had survived a stroke at least six months prior. Participants received training of either high-intensity stepping performing variable, difficult tasks; high-intensity stepping performing only forward walking; or low-intensity stepping of variable tasks. Variable tasks included walking on uneven surfaces, up inclines and stairs, over randomly placed obstacles on a treadmill and across a balance beam.
The researchers found that survivors in both the high-intensity, variable training and high-intensity, forward walking groups walked faster and farther than the low-intensity, variable training group. For all walking outcomes, 57% to 80% of participants in the high-intensity groups had important clinical gains, while only 9% to 31% of participants did so following low-intensity training. High-intensity variable training also resulted in improved dynamic balance while walking and improved balance confidence.
Hornby noted that no serious adverse events occurred during the training sessions, suggesting stroke survivors can be pushed to higher intensity walking with more variable tasks during rehabilitation.
"Rehabilitation that allows walking practice without challenging the nervous system doesn't do enough to make a statistical or clinically significant difference in a patient's recovery after a stroke," Hornby said. "We found that when stroke patients are pushed harder, they see greater changes in less time, which translates into more efficient rehabilitation services and improved mobility."
Ultimately, their goal is to incorporate high-intensity variable step training into regular clinical rehabilitation protocols.
The study was small compared to larger, multi-centre clinical trials. Hornby said the next step would be to test high-intensity, variable step training in larger patient populations in a large, multi-centre clinical trial.
Abstract
Background and Purpose: The amount of task-specific stepping practice provided during rehabilitation poststroke can influence locomotor recovery and reflects one aspect of exercise dose that can affect the efficacy of specific interventions. Emerging data suggest that markedly increasing the intensity and variability of stepping practice may also be critical, although such strategies are discouraged during traditional rehabilitation. The goal of this study was to determine the individual and combined contributions of intensity and variability of stepping practice to improving walking speed and distance in individuals poststroke.
Methods: This phase 2, randomized, blinded assessor clinical trial was performed between May 2015 and November 2018. Individuals between 18 and 85 years old with hemiparesis poststroke of >6 months duration were recruited. Of the 152 individuals screened, 97 were randomly assigned to 1 of 3 training groups, with 90 completing >10 sessions. Interventions consisted of either high-intensity stepping (70%–80% heart rate reserve) of variable, difficult stepping tasks (high variable), high-intensity stepping performing only forward walking (high forward), and low-intensity stepping in variable contexts at 30% to 40% heart rate reserve (low variable). Participants received up to 30 sessions over 2 months, with testing at baseline, post-training, and a 3-month follow-up. Primary outcomes included walking speeds and timed distance, with secondary measures of dynamic balance, transfers, spatiotemporal kinematics, and metabolic measures.
Results: All walking gains were significantly greater following either high-intensity group versus low-variable training (all P<0.001) with significant correlations with stepping amount and rate (r=0.48–60; P<0.01). Additional gains in spatiotemporal symmetry were observed with high-intensity training, and balance confidence increased only following high-variable training in individuals with severe impairments.
Conclusions: High-intensity stepping training resulted in greater improvements in walking ability and gait symmetry than low-intensity training in individuals with chronic stroke, with potential greater improvements in balance confidence.
Authors
T George Hornby, Christopher E Henderson, Abbey Plawecki, Emily Lucas, Jennifer Lotter, Molly Holthus, Gabrielle Brazg, Meghan Fahey, Jane Woodward, Marzieh Ardestani, Elliot J Rot
[link url="https://www.heart.org/en/news/2019/08/22/stroke-survivors-recover-better-with-stepped-up-rehab"]American Heart Association material[/link]
[link url="https://www.ahajournals.org/doi/10.1161/STROKEAHA.119.026254"]Stroke abstract[/link]