Photograph of Pollock and trainer Simon O’Donnell, courtesy of Pollock.
A 39-year-old man who has had paralysis for four years was able to voluntarily control his leg muscles and take thousands of steps using an Ekso Bionics exoskeleton during five days of training-and for two weeks afterward-a team of scientists from the University of California, Los Angeles (UCLA), reported. They said this is the first time that a person with chronic, complete paralysis has regained enough voluntary control to actively work with a robotic device designed to enhance mobility. In addition to the exoskeleton, the man was aided by a novel noninvasive spinal stimulation technique. His leg movements also resulted in other health benefits, including improved cardiovascular function and muscle tone. The researchers do not describe the achievement as “walking” because no one with complete paralysis has independently walked in the absence of the exoskeleton and electrical stimulation of the spinal cord.
The researchers treated Mark Pollock, who lost his sight in 1998 and later became the first man with vision impairment to race to the South Pole. In 2010, Pollock fell from a second-story window and suffered a spinal cord injury that left him with paralysis from the waist down.
At UCLA, Pollock made substantial progress after receiving a few weeks of physical training without spinal stimulation and then just five days of spinal stimulation training in a one-week span, for about an hour per day.
“In the last few weeks of the trial, my heart rate hit 138 beats per minute,” Pollock said. “This is an aerobic training zone, a rate I haven’t even come close to since being paralyzed while walking in the robot alone, without these interventions. That was a very exciting, emotional moment for me, having spent my whole adult life-before breaking my back-as an athlete.”
The research was published by the IEEE Engineering in Medicine and Biology Society.
“It will be difficult to get people with complete paralysis to walk completely independently, but even if they don’t accomplish that, the fact they can assist themselves in walking will greatly improve their overall health and quality of life,” said V. Reggie Edgerton, PhD, senior author of the research and a UCLA distinguished professor of integrative biology and physiology, neurobiology, and neurosurgery.
“If the robot does all the work, the subject becomes passive and the nervous system shuts down,” Edgerton said.
The data showed that Pollock was actively flexing his left knee and raising his left leg and that during and after the electrical stimulation, he was able to voluntarily assist the robot during stepping; it wasn’t just the robotic device doing the work.
“For people who are severely injured but not completely paralyzed, there’s every reason to believe that they will have the opportunity to use these types of interventions to further improve their level of function. They’re likely to improve even more,” Edgerton said. “We need to expand the clinical toolbox available for people with spinal cord injury and other diseases.”
Editor’s note: This story was adapted from materials provided by UCLA.
