Children with complete paralysis due to spinal cord injuries gained the ability to take steps thanks to an innovative, external electrical stimulation technique at the University of Louisville.
Researchers in UofL’s Kosair for Kids Center for Pediatric NeuroRecovery provided a combination therapy to five children with complete paralysis. The children, ages 7-12, took part in a clinical study in which they received external electrical stimulation over the spine, combined with activity-based therapy and encouragement to consciously intend to step. During the study, the children all gained the ability to take steps and experienced unexpected improvements in sensation, bladder function, transferring and other abilities. The study was published in the September 2025 issue of the journal Brain.
“We have found that electrical stimulation can “charge” the spinal cord, making it possible for a paralyzed individual to step voluntarily,” said Andrea Behrman, professor in the UofL Department of Neurological Surgery and director of the Center for Pediatric NeuroRecovery, who led the study. “This ability increases over time when the stimulation is combined with locomotor training and mental intent to step.”
Stimulation + activation + intent
In the study, children who were completely paralyzed for more than a year, unable to move below their level of spinal injury, participated in a series of 60 sessions that included noninvasive, transcutaneous (through the skin) electrical stimulation of the sensory nerves to the spinal cord and specialized physical therapy.
The electrical stimulation was applied with a specially designed technique for external electrical stimulation developed by Yury Gerasimenko, now gratis professor of the UofL Department of Physiology. The technique consisted of several small stimulators, about the size of a quarter, placed on the child’s skin over the sensory nerves of the spinal cord. During the sessions, electrical stimulation was applied through the pads while the children took part in physical therapy known as activity-based locomotor training.
This therapy consists of researchers and therapy technicians manually facilitating the child’s legs in stepping motions as they lay on their side on a table with their legs suspended and also during assisted walking with part of their body weight supported over a treadmill. In addition, the children were encouraged to consciously attempt to step.
Over the course of the study, the children were able to initiate and control the stepping themselves. After various numbers of sessions, they were able to take steps over ground, voluntarily initiating the steps both with and without the stimulation present. Three to six months after the sessions were completed, all of the children still were able to take steps with and without the stimulation.
“The results we see with this study confirm what I have learned more and more over the last two decades working with children with spinal cord injury,” Behrman said. “Your spinal cord is more than a conduit or a pipeline for nervous system messages. It processes information and is smart like your brain. The spinal cord can’t decide to go to Starbucks for coffee, but it can help you with more automatic movements such as sitting up better and taking steps. It also works somewhat like a battery and needs the right charge to help produce steps and respond to therapy.”
For many years, the medical community as a whole has believed that after injury in which communication along the spinal cord was interrupted and the patient could not move on their own, that function below the injury could never be restored. As a result, treatment for most people with complete paralysis included helping them adapt to mobility with wheelchairs and other forms of assistance.
For the parents of children participating in Behrman’s studies and clinical care, even the small gains achieved through the sessions have a significant positive impact on their child’s quality of life and often, their health.
Kalyn MacIntyre, whose son Malcolm participated in the study, said that even three years after the study concluded, he retains many of the benefits he gained from his sessions.
“He can still step on the treadmill, he can kick a ball consistently. He can now feel when he needs to go to the restroom and his overall health has been good,” Kalyn said, adding that he also has sensory gains. “I don’t know what his future is as far as walking. I just want him to be functionally capable of doing things on his own – to have more independence – and I want him to be healthy. We have more of that here because of this study.”
The personal connection
One of the most challenging aspects of the research is motivating the children during long training sessions.
“We can have the most beautifully designed study, but if a child can’t get into it and you can’t help them be successful, it will not work,” Behrman said. “You can’t just come in and say, ‘Do this 50 times.’ For each child, you must figure out how to connect with who they are.”
To engage them in the activities, Behrman and the therapists working with the children have cultivated the art of motivation by incorporating their personal interests. One child in the study was a basketball player before he was injured, so Behrman used a whistle to encourage him to go faster or drive harder, similar to when he was running drills for basketball.
For Malcolm, the research staff devised a point system to reward him for every time he was able to kick a ball. Behrman recalled one session when she told him that instead of the 10 or 20 points he received for kicking the ball off the treadmill, she would award him 10,000 points if he could kick the ball to hit a target on the opposite wall.
On the next try, Malcolm’s kick sent the ball sailing across the room, squarely hitting the target.
Previous success
Previously, researchers at UofL achieved remarkable success in restoring function to adults with spinal cord injury in studies using surgically implanted electrical spinal cord stimulators. In one study, adults who were completely paralyzed were able to take steps over ground with stimulation after a series of intensive physical therapy sessions and mental intent to take steps.
This new study shows that similar results can be achieved without the invasive procedure. In addition, the adults could only step when the stimulator was on, whereas the children in Behrman’s study were able to step long after the stimulation sessions had ceased.
For additional photos and video clips, visit UofL Ped NeuroRecovery images 2025. All images courtesy University of Louisville. The images with “study image” in the name were captured during the study sessions, 2021-2023.
