Completely paralyzed man voluntarily moves his legs, UCLA scientists report

In 1998, athlete Mark Pollock became the first blind man to race to the South Pole; now "Iron ElectriRx" man is making history again --- in a robotic exoskeleton
September 2, 2015

Mark Pollock and trainer Simon O’Donnell (credit: Mark Pollock)

A 39-year-old man who had been completely paralyzed for four years was able to voluntarily control his leg muscles and take thousands of steps in a “robotic exoskeleton” device during five days of training, and for two weeks afterward, UCLA scientists report.

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 robotic device, the man was aided by a novel noninvasive spinal stimulation technique that does not require surgery. His leg movements also resulted in other health benefits, including improved cardiovascular function and muscle tone.

The new approach combines a battery-powered wearable bionic suit that enables people to move their legs in a step-like fashion, with a noninvasive procedure that the same researchers had previously used to enable five men who had been completely paralyzed to move their legs in a rhythmic motion.

That earlier achievement is believed to be the first time people who are completely paralyzed have been able to relearn voluntary leg movements without surgery. (The researchers do not describe the achievement as “walking” because no one who is completely paralyzed has independently walked in the absence of the robotic device and electrical stimulation of the spinal cord.)

Mountain racing blind? No problem. Paralyzed? “Iron ElectriRx” man is aceing that too

In the latest study, the researchers treated Mark Pollock, who lost his sight in 1998 and later became the first blind man to race to the South Pole. In 2010, Pollock fell from a second-story window and suffered a spinal cord injury that left him paralyzed from the waist down.

At UCLA, outfitted with the robotic exoskeleton, 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 a 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.”

Even in the years since he lost his sight, Pollock has competed in ultra-endurance races across deserts, mountains and the polar ice caps. He also won silver and bronze medals in rowing at the Commonwealth Games and launched a motivational speaking business.

“Stepping with the stimulation and having my heart rate increase, along with the awareness of my legs under me, was addictive. I wanted more,” he said.

The research was published by the IEEE Engineering in Medicine and Biology Society, the world’s largest society of biomedical engineers.

Expanding the clinical toolbox for the paralyzed

“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, senior author of the research and a UCLA distinguished professor of integrative biology and physiology, neurobiology and neurosurgery.

The procedure used a robotic device manufactured by Richmond, California-based Ekso Bionics that captures data that enables the research team to determine how much the subject is moving his own limbs, as opposed to being aided by the device.

“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.”


Edgerton Lab, University of California Los Angeles | Paralyzed subject Training in Ekso during spinal cord stimulation

The future of spinal-cord research

Edgerton and his research team have received many awards and honors for their research, including Popular Mechanics’ 2011 Breakthrough Award.

“Dr. Edgerton is a pioneer and we are encouraged by these findings to broaden our understanding of possible treatment options for paralysis,” said Peter Wilderotter, president and CEO of the Christopher and Dana Reeve Foundation, which helped fund the research. “Given the complexities of a spinal cord injury, there will be no one-size-fits-all cure but rather a combination of different interventions to achieve functional recovery.

“What we are seeing right now in the field of spinal cord research is a surge of momentum with new directions and approaches to remind the spine of its potential even years after an injury,” he said.

NeuroRecovery Technologies, a medical technology company Edgerton founded, designs and develops devices that help restore movement in patients with paralysis. The company provided the device used to stimulate the spinal cord in combination with the Ekso in this research.

Edgerton said although it likely will be years before the new approaches are widely available, he now believes it is possible to significantly improve quality of life for patients with severe spinal cord injuries, and to help them recover multiple body functions.

In addition to the Reeve foundation, the research was funded by the National Institutes of Health’s National Institute of Biomedical Imaging and Bioengineering, the F. M. Kirby Foundation, the Walkabout Foundation, the Dana and Albert R. Broccoli Foundation, Ekso Bionics, NeuroRecovery Technologies and the Mark Pollock Trust.

Almost 6 million Americans live with paralysis, including nearly 1.3 million with spinal cord injuries.


Abstract of Iron ‘ElectriRx’ Man: Overground Stepping in an Exoskeleton Combined with Noninvasive Spinal Cord Stimulation after Paralysis

We asked whether coordinated voluntary movement of the lower limbs could be regained in an individual having been completely paralyzed (>4 yr) and completely absent of vision (>15 yr) using a novel strategy – transcutaneous spinal cord stimulation at selected sites over the spinal vertebrae with just one week of training. We also asked whether this stimulation strategy could facilitate stepping assisted by an exoskeleton (EKSO, EKSO Bionics) that is designed so that the subject can voluntarily complement the work being performed by the exoskeleton. We found that spinal cord stimulation enhanced the level of effort that the subject could generate while stepping in the exoskeleton. In addition, stimulation improved the coordination patterns of the lower limb muscles resulting in a more continuous, smooth stepping motion in the exoskeleton. These stepping sessions in the presence of stimulation were accompanied by greater cardiac responses and sweating than could be attained without the stimulation. Based on the data from this case study it appears that there is considerable potential for positive synergistic effects after complete paralysis by combining the overground stepping in an exoskeleton, a novel transcutaneous spinal cord stimulation paradigm, and daily training.