Researchers from the NIH Clinical Center’s Rehabilitation Medicine Program have developed the first robotic exoskeleton specially designed to help treat crouch gait in children with cerebral palsy (CP).
Crouch (or flexed-knee) gait is the excessive bending of the knees while walking, a common and debilitating condition in children with CP. Crouch gait can lead to progressive degeneration of the ability to walk.
Led by Thomas Bulea, a research team created an exoskeleton that provides powered knee-extension assistance at key points during the walking cycle by tracking the natural movement of children’s limbs.
“To date most wearable exoskeletons are intended for adults with paralysis, with the exoskeleton replacing the lost function of the user’s muscles to restore walking ability. Rather than restoring lost function, our exoskeleton was designed to change the way children with crouch gait from cerebral palsy walk,” Bulea said in a press release.
A prototype of the exoskeleton was tested in seven individuals, ages 5 to 19, to determine its safety and effectiveness, to evaluate its effect on voluntary muscle activity, and to study short-term changes in lower limb gait.
The device was found to be safe and to effectively reduce crouch gait during walking in ambulatory children with CP. Most of the children improved their knee extension by up to 37 degrees while wearing the brace.
Additionally, the improvement in knee extension occurred without a decrease in the activity of the knee extensor muscle, meaning that the children worked together with the exoskeleton rather than solely relying on the robot to straighten their legs while walking.
For some of these children, it was the first time they were able to walk while standing tall.
“Our results show that the exoskeleton can safely and effectively change the posture of a child while they wear it. The exciting part is that the children’s muscle activity was preserved when they walked in this new way with the exoskeleton, suggesting that long-term use of this device might be a viable way to train a new walking pattern in this population,” Bulea said.
Bulea and his team believe that these results could represent an important first step toward implementing a technology-assisted approach to treating crouch gait, and suggest that powered knee exoskeletons could be considered as an alternative to, or in conjunction with, traditional treatments. The evidence could be sufficient to support larger and longer controlled studies.
“Ultimately, our goal is to have this device reach as many children who can benefit as possible,” Bulea said. “We are also planning studies in children with more severe gait deficits from cerebral palsy who are therefore at elevated risk for declining mobility, as well as in other disorders such as spina bifida or muscular dystrophy.”
Findings from this study were published in August 2017 in the Science Translational Medicine journal, under the title, “A lower-extremity exoskeleton improves knee extension in children with crouch gait from cerebral palsy.”