More than 17 million people around the world are living with cerebral palsy, a movement disorder that occurs when motor areas of a child’s brain do not develop correctly or are damaged early in life. Many of those affected were born extremely prematurely and suffered brain hemorrhages shortly after birth. One of the condition’s most common symptoms is crouch gait, which is an excessive bending of the knees that can make it difficult or even impossible to walk. Now, a new robotic device developed by an NIH research team has the potential to help kids with cerebral palsy walk better.
What’s really cool about the robotic brace, or exoskeleton is that it’s equipped with computerized sensors and motors that can detect exactly where a child is in the walking cycle—delivering bursts of support to the knees at just the right time. In fact, in a small study of seven young people with crouch gait, the device enabled six to stand and walk taller in their very first practice session!
For people with cerebral palsy, crouch gait is now treated with a variety of approaches, often including wearing orthotic ankle braces that help to stabilize their legs. Still, about half of kids with cerebral palsy can’t walk by early adulthood. Their muscles simply can’t keep up with their growing bodies.
That’s led to development of many robotic training devices, though most are still restricted to use in a supervised clinical setting. In the new study, led by Thomas Bulea at the NIH Clinical Center in Bethesda, MD, the team wanted to develop a wearable system for potential home use to help keep more kids walking as they grow into adulthood.
The researchers decided to turn to robotic exoskeleton technology, which has shown promise for bringing mobility to adults paralyzed from strokes or spinal cord injuries. You may recall that remarkable moment when a paraplegic man used a mind-controlled robotic exoskeleton, developed with NIH support, to kick off soccer’s 2014 World Cup.
But those devices are designed to do all the work, taking their passengers along for the ride. The NIH team wanted to take a different tack for kids with cerebral palsy: designing a device to help power their knee extension when walking while also exercising their muscles.
To find out how helpful their robotic exoskeleton could be, the researchers enlisted seven children between ages 5 and 19 with crouch gait. All could walk reasonably well—at least 30 feet without a walking aid.
After an initial fitting, participants came to the NIH Clinical Center for five additional practice sessions with the exoskeleton, each lasting several hours. A person walked behind them carrying a control box weighing less than 5 pounds. As reported recently in Science Translational Medicine, all of the children were able to walk safely and independently using the exoskeleton without any other aid .
Detailed biomechanical measurements showed that the device improved the kids’ ability to extend and straighten their knees. But their parents and others observing didn’t need to see the data to tell them that. In fact, Bulea says some parents were visibly moved at watching their kids walk in a more upright position for the first time.
The kids’ walking in the exoskeleton continued to improve with practice. By the sixth visit, they could extend their knees better, gaining on average about 13 degrees in knee angle; lift their feet better off the ground; and take larger steps. Also, none of the kids fell and their walking speed increased.
Importantly, the researchers found that the kids’ kept on using their muscles while wearing the exoskeleton. They weren’t simply allowing the device to do the walking for them.
While larger and longer-term studies are needed, these findings suggest that a responsive robotic device could train a more-upright walking pattern in children with cerebral palsy and perhaps other movement disorders, such as muscular dystrophy and spina bifida. The researchers hope that, with further modifications to their prototype, the exoskeleton will indeed be ready for use at home.
Also looking ahead, the researchers say they hope to develop exoskeletons that could be used in even younger kids. After all, the earlier that children with cerebral palsy can learn to walk more upright, the better. They’d also like to test them in kids whose walking ability is already more severely compromised. If successful, that should make us all stand a little taller for the important research progress that’s being made on behalf of our friends and loved ones with cerebral palsy.
 A lower-extremity exoskeleton improves knee extension in children with crouch gait from cerebral palsy. Lerner ZF, Damiano DL, Bulea TC. Sci Transl Med. 2017 Aug 23;9(404).
Cerebral Palsy (National Institute of Child Health and Human Development/NIH)
Rehabilitation Medicine (NIH Clinical Center)
Source – NIH Support: Clinical Center