Crouch gait occurs when there is excessive bending of the knees while walking. It is a common condition in children with cerebral palsy. The NIH reports that even with conventional treatments, crouch gait can develop into the degeneration of walking function and eventually the loss of walking ability in about half of adults with the disorder.
NIH Clinical Center researchers tested a prototype of the exoskeleton to determine if the motors were safe and effective for reducing crouch gait and evaluate its effects on voluntary muscle activity. The exoskeleton offers powered knee extension assistance during key point while walking.
The study included seven participants between the ages of 5 and 19 and were diagnosed with crouch gait and could walk at least 30 feet without a walking aid.
All of the participants on the study were able to walk independently without using mobility aids or therapist assistance. Six of the seven were able to do so after the first practice session.
Knee extension improvements were tracked in six participants who had gains that were similar to or greater than any average improvements that occurred from invasive surgical procedures. Gains in knee extensions were shown to have occurred without a reduction in knee extensor muscle activity, which was an indicator of the participants working with the exoskeleton instead of offloading the straightening of the leg while walking with the robot.
“Most wearable exoskeletons have been designed for adults with paralysis, with the exoskeleton replacing the lost function of the user’s. We sought to create a device that could safely and effectively improve the posture of children with crouch gait while they walked,” Thomas Bulea, principal investigator of the study and staff scientist in the NIH Clinical Center Department of Rehabilitation Medicine, said in a press release. “The improvements in their walking, along with their preserved muscle activity, make us optimistic that our approach could train a new walking pattern in these children if deployed over an extended time. This study paves the way for the exoskeleton’s use outside the clinic setting, greatly increasing the amount and intensity of gait training, which we believe is key to successful long-term outcomes in this population.”
The NIH reports that cerebral palsy is one of the most common childhood movement disorders in the U.S., causing about 10,000 new cases each year. It is generally caused by a brain injury or an abnormality during infancy or early childhood.
The exoskeleton study is one of the first steps toward the NIH’s goal of creating a device-based approach to treating crouch gait. The researchers also suggest that powered keen exoskeletons should be studied as an alternative to conventional treatments or as a supplement to treatment.
The research was published in the Science Translational Medicine journal.