A variety of robotics devices exist, designed to restore movement to paralysed or partially paralysed limbs. They often look like something from a science fiction film but can be used to aid everyday living, e.g. a mother can wear a robotic splint to pick up her children’s toys. It is often possible to use these aids after one training session. A typical robotic hand aid has electrodes that are attached to key muscles. It sends low-level electrical impulses to the junctions between the nerves and the muscles, so you can open and close your hand at will. The Hand-Wrist Assisting Robotic Device, or HOWARD, for example, is like a robotic splint that helps your brain to relearn how to move your hand. HOWARD senses how much progress you have made when trying to grasp an object, then completes the movement for you.1
It is also possible to use robotics as part of rehabilitation therapy. Robotic devices can be as effective as working with a therapist, in some cases even more so.2 There is a range of robotic leg braces that can generate leg and foot movements, or help to create a more natural walk. For example, Lokomat is a type of harness that supports your body while your legs are moved to simulate walking. It would take two physiotherapists to help a patient perform this exercise. With Lokomat, you can exercise more often and for longer periods.3
Some devices help to stimulate nerve growth and retrain muscles in order to regain natural movement. There is also evidence that some robotic devices can help to minimise a variety of secondary complications associated with paralysis, such as pain, poor blood circulation, and tightness that can lead to a claw-like hand. The makers of the NESS H200 hand aid conducted a study of 77 stroke survivors. One of the participants explains:
‘Whether the device, or the exercises or spontaneous recovery was responsible, I cannot say for certain. But after 12 weeks of electrotherapy and exercise, my hand remained open instead of becoming clenched. The blood flow in my arm increased, and serious swelling disappeared. In videotaped tests, I did increasingly well at moving blocks and empty cans from one place to another. Now, with exercise only, the hand function has continued to improve.’4
Robotic devices are available to help with a range of activities, including balancing and climbing stairs, e.g. the KineAssist is a ‘wheeled device’ that supports you from behind as you walk and perform other exercises.5 Several robotic devices have received FDA clearance in the USA, or equivalent approval in their country of origin. It is possible to buy many of these for home use, although they typically cost more than €6,000. We recommend that you consult your physical therapist before you consider this option.
Possible benefits of Robotics for stroke
Many post-stroke problems are caused by loss of brain cells. Researchers at MIT believe the brain's ability to build new mental maps to replace lost brain cells means it is possible to regain movement through repetitive exercise. They explain:
‘Devices such as the MIT-developed robotic brace can help people exploit their neural plasticity - the increasingly recognized ability of the brain to rewire itself in response to experience and training.’ 6
This ability to ‘re-wire’ your brain means that you can recover from a stroke many years after it happened. The robotic device closes the gap between your intention to move (thinking) and your ability to move (physical movement). It builds new pathways in your brain, so that wanting to move your finger and actually moving your finger become connected over time. The device senses your ‘electrical muscle activity’ and sends that information to a motor. This allows you to control the affected limbs. The following example is a case that researchers at MIT studied in 2007:
‘At age 32, Maggie Fermental suffered a stroke that left her right side paralyzed. After a year and a half of conventional therapy with minimal results, she tried a new kind of robotic therapy developed by MIT engineers. A study to appear in the April 2007 issue of the American Journal of Physical Medicine & Rehabilitation shows that the device, which helped Fermental, also had positive results for five other severe stroke patients in a pilot clinical trial.
Fermental, a former surgical nurse, used the rehabilitation device 18 times over nine weeks. After 16 sessions, Fermental, now a stroke education nurse at Beth Israel Hospital, was able to fully bend and straighten her elbow on her own for the first time since the stroke. "It was incredible to be able to move my arm again on command," she said. "Cooking, dressing, shopping, turning on light switches, opening cabinets - it's easier now that I have two arms again.”’ 7
After a stroke, many people experience their foot dropping when they walk; this is due to partial paralysis of the leg. Robotic aids exist that can be worn on your lower leg instead of a rigid leg or foot brace. In the robotic version,
‘Sensors detect whether the patient's foot is in the air or on the ground, and electrodes transmit painless electrical stimulation to the peroneal nerve to activate the calf muscle and correct their gait.’8
There are numerous robotic devices that can help with stroke recovery. Many of these have been tested and results show that they can help to restore movement after a stroke. In 2008, a systematic review examined the evidence to see if robotic devices could improve walking after a stroke. They ‘included 8 randomized controlled trials with 414 participants’ and concluded:
‘Patients who receive electromechanical-assisted gait training in combination with physiotherapy after stroke are more likely to achieve independent walking than patients receiving gait training without these devices.’9
There is also evidence that the benefits of robotic-assisted therapy remain after the therapy has finished.10
Researchers at the University of Southampton have combined the benefits of robotic training with the fun of video gaming to produce ARM (Assessment, Rehabilitation, Movement). This is a home-based therapy, designed to improve hand and arm function after a stroke. ARM has won national and international awards, as well as receiving a grant of £2M from the National Institute for Health Research (NIHR) to bring it into the British health care system.
A large scale study on rehabilitation therapy concluded that robotic therapy was more effective when used over a longer time. Researchers used a randomised, controlled trial involving 127 patients with moderate-to-severe upper-limb impairment, six months or more after a stroke. Of the 127 patients, 49 received intensive robot-assisted therapy, 50 received intensive comparison therapy, and 28 received usual care. They concluded:
‘In patients with long-term upper-limb deficits after stroke, robot-assisted therapy did not significantly improve motor function at 12 weeks, as compared with usual care or intensive therapy. In secondary analyses, robot-assisted therapy improved outcomes over 36 weeks as compared with usual care but not with intensive therapy.’11
The intensive therapy provided in the test was specifically developed for comparison purposes. It is not generally available and due to the heavy physical demands on the therapist, it is not likely to be widely used. For this reason, robotic-assisted physical therapy could be very important. As one of the researchers in the study explains,
"If you can get a therapist to work at that pace with a patient, certainly the benefits are roughly the same, and we showed this benefit when we designed this intensive comparison group, but it’s not practical,” says Krebs. “Robotics and automation technology are ideal for this kind of highly repetitive tasks. We’re using robotic technology to create a tool for the therapist to afford this kind of high-intensity therapy while maintaining the therapist supervisory role, deciding what is right for a particular patient.”12
Arguments against the use of Robotics for stroke
At the moment, robotic devices are yielding good results. However, because they as so new, even manufacturers agree that the true benefits will only emerge after more research:
‘Generally, electrical stimulation has been demonstrated to improve motor control; future research will determine the specific long-term benefits of the NESS L300.’ 13
It may be exciting to contemplate the brave new world of robotics. However, some researchers advise us to remember that robots will never replace therapists. According to Elliot J. Roth, MD, Senior Vice President for Medical Affairs at the Rehabilitation Institute of Chicago,
‘Their main advantages are that they make therapy more consistent, predictable and measurable.’ 14
There is also a danger that the user will depend too much on the robotic device and lose the opportunity to learn through natural mistakes. George Hornby, a researcher at the Rehabilitation Institute of Chicago, argues that robots should be used for a short period only:
‘"Robots are like training wheels," he says. "They can get you to a certain point, but after that, you have to learn to correct your own mistakes."’ 15
Notes and references
- Hand-Wrist Assisting Robotic Device, or HOWARD, was developed at the University of California at Irvine. It is like a pneumatic splint that monitors and assists with grasping movements.
- ‘Waking up the brain after stroke’ by Yasmine Iqbal from the July-August ACP Observer, 2007 by the American College of Physicians. See also ‘Robotics in neuro-rehabilitation’ by Pignolo L. In J Rehabil Med. 009 Nov;41(12):955- 60.
- The Lokomat is manufactured by Hocoma, a Swiss-based company.
- ‘Israeli-made device helps restore use of paralyzed hands’ by David Brinn and Sharon Kanon. ISRAEL21c, November 21, 2004
- The KineAssist is being developed at the Rehabilitation Institute of Chicago. It is the first over-ground walking and balance exercise system.
- ‘Robotic brace aids stroke recovery’ by Deborah Halber. MIT News, News Office Correspondent, March 20, 2007
- ‘Robotic brace aids stroke recovery, by Deborah Halber. MIT News, News Office Correspondent, March 20, 2007
- NESS L300™ neuro-rehabilitation system. Rehabilitation Hospital of the Cape and the Islands.
- ‘Electromechanical-Assisted Gait Training With Physiotherapy May Improve Walking After Stroke’ by Jan Mehrholz, DrPH; Cordula Werner, Joachim Kugler, Marcus Pohl. In Stroke. 2008;39:1929.
- ‘A Pilot Study of Randomized Clinical Controlled Trial of Gait Training in Subacute Stroke Patients With Partial Body-Weight Support Electromechanical Gait Trainer and Functional Electrical Stimulation’ by Maple F.W. Ng, BSc; Raymond K.Y. Tong, Leonard S.W. Li. In Stroke. 2008;39:154-160
- Lo AC. et al. 'Robot-Assisted Therapy for Long-Term Upper-Limb Impairment after Stroke'. In New England Journal of Medicine, April 16, 2010, 362:pp. 1772-83, p. 1772.
- Trafton A, 'Robotic therapy helps stroke patients regain function'. MIT News, April 10, 2010
- Trafton A, 'Robotic therapy helps stroke patients regain function'. MIT News, April 10, 2010
- Impatient Rehabilittation Medicine Center at New York Presbyterian/Weill Cornell USA. 26-May-07, NYP-NEWS
- ‘Waking up the brain after stroke’ by Yasmine Iqbal from the July-August ACP Observer 2007 by the American College of Physicians.