Amanda Boxtel uses the Ekso on the left and Agnes Fejerty uses a ReWalk prototype on the right in this 2012 photo.
Exos, as they are known as a class, may also offer people a way of ambulating through narrow doorways, into once inaccessible places and a new world of possibilities. The devices are much improved from three years ago — more adjustable, refined, sophisticated and presumably fast enough to get through a crosswalk before the light changes. They still bring to mind a headless cyborg, especially the ReWalk and Ekso, with the shoulder straps and backpack.
“Exos can be used for gait training, mobility or exercise,” says physical therapist Clare Hartigan, who has worked with all three devices at Shepherd Center. “They often allow us to do more steps per session than other forms of walking therapy.”
Preliminary study reports have suggested that lower extremity exos may have benefits such as improved balance, conditioning, neuromuscular cortical activity; reduction in spasticity and pain, as well as increased personal well-being and quality of life. Other trials have suggested improvements in step speed, stride length and symmetry with stroke survivors, although results were inconclusive with SCI; no trial results exist for MS or TBI. In general, they all employ sensors to monitor trunk position and activate with user position changes.
But don’t plan on retiring those wheels just yet; these exoskeletons are meant to complement chairs, not replace them. They come with price tags as high as $70,000 and no proven track record of reliability. The FDA requires a product life of five million cycles (or steps) for approval.
Exos remain works in progress. As yet, no rigorous research exists which allows for any cause-effect conclusions regarding any medical benefits. Any claims of benefits cited below are based on manufacturers’ studies. Or, as Kevin Ogar put it, “I’d use it the same as my braces, to get around my house, to do certain chores, but I wouldn’t get rid of the chair.”
ReWalk: First to Get FDA Approval
ReWalk claims to be the most widely used and most studied exo, as well as the first to gain FDA approval for sale to individuals.
The company sees its device as appropriate for both gait training and personal mobility. The device responds to upper-body motions, which are monitored by a sensor that triggers both stepping and overall gait patterns for walking and shifting from sitting to standing. Users are free to use their hands.
The personal ReWalk has improved since 2012, with better electronics, upgraded sensors, an all-black look and other user-friendly changes. The battery life provides on average 3.5 hours of actual walking, which ReWalk considers all-day use. The device is recommended for T4 and lower injuries and requires buyers be trained and tested at one of the company’s advanced training centers.
ReWalk ($71,600) says it has been successful in securing full reimbursement from an insurance carrier for a U.S. purchaser, with more in process. The company has set up a department devoted to reimbursement and will go to insurance companies on behalf of purchasers, pitching benefits — improved balance, core strength, bowel/bladder function, bone density, body composition, fitness and sleep patterns, as well as decreased pain and spasticity and reduced hospitalizations and dependence on medications. The statistics are based on small internal studies and testimonials from “ReWalkers.”
Ekso Bionics: Programmable Assisted Walking
“Right now we’re focusing on building the best rehabilitation device possible for gait training,” says Darrell Musick, Ekso Bionics vice president of clinical services. “We can get in hundreds of steps in a session in a safe way while compensating for muscle weakness. People who have used both our current GT and the older models see significant improvements and now find it easier to use,” Musick adds.
The user shifts weight and activates footplate sensors that initiate each step. Battery-powered motors compensate for weak or non-existent muscle function. The Ekso now offers a variable assist mode, an automatic mode and a manual mode and can be programmed to walk at a certain speed and with a specific stride length. If the user does nothing, the device will do all the work; when the user engages whatever leg muscles they have available, the device senses how much assistance is needed and backs off, like a cruise control. The assistance levels can be reduced or turned off on one side or the other — for those dealing with hemiplegia or asymmetrical strength.
The Ekso is presently a “Class II pending” medical device (medium safety risk) to provide functional-based rehabilitation, over-ground gait training, and upright weight-bearing exercise under the supervision of a physical therapist, and is designed to fit a wide range of users.
“The Ekso GT supports the re-learning of a correct step pattern and allows more steps at a faster speed than with traditional rehabilitation,” adds scientist Karen Nolan of the Kessler Foundation Research Center.
Indego: Lightweight, Wheelchair Compatible
Parker-Hannifin is developing the Indego — for relearning walking as well as a personal mobility assistive device for individuals who are partially or fully walking-impaired. The company sees its device as being used in conjunction with a chair, not replacing it — for greater independence.