Robotic Exoskeleton Offers Approach to Alleviate Crouch Gait in Kids with Cerebral Palsy

Researchers from the Clinical Center’s rehabilitation medicine department have created the first robotic exoskeleton specifically designed to treat crouch (or flexed-knee) gait in children with cerebral palsy by providing powered knee extension assistance at key points during the walking cycle.

Crouch gait, the excessive bending of the knees while walking, is a common and debilitating condition in children with cerebral palsy. Despite conventional treatments (including muscle injections, surgery, physical therapy and orthotics), crouch gait can lead to a progressive degeneration of the walking function, ultimately resulting in the loss of walking ability in roughly half of adults with the disorder.

CC researchers tested their prototype powered knee exoskeleton in a cohort study that followed 7 individuals between the ages of 5 and 19 who were diagnosed with crouch gait from cerebral palsy. The work was reported in Science Translational Medicine.

Walking with the exoskeleton was well-tolerated, with all participants able to walk independently without mobility aids or therapist assistance; six were able to do so in the first practice session. Improvements in knee extension were observed in six participants, with gains similar to or greater than average improvements reported from invasive surgical interventions. Importantly, the gains in knee extension occurred without a reduction in knee extensor muscle activity, indicating that these participants worked with the exoskeleton rather than offloading the task of straightening the leg during walking to the robot.

“Most wearable exoskeletons have been designed for adults with paralysis, with the exoskeleton replacing the user’s lost function,” said Dr. Thomas Bulea, principal investigator of the study. “We sought to create a device that could safely and effectively improve the posture of children with crouch gait while they walked. 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.”

Cerebral palsy is the most prevalent childhood movement disorder in the U.S., with approximately 10,000 new cases diagnosed each year. It is caused by a brain injury or abnormality in infancy or early childhood that disrupts the control of movement, posture and balance.