Bionic Breakout: Robotic-Assisted Therapy Is Evolving

Robotic-assisted therapy has made significant strides in the past 15 years. Will it overtake conventional physical therapy?

By Zac Haughn, Senior Associate Editor

In 1887, physical therapists received recognition by Sweden’s National Board of Health and Welfare. This was the first official acknowledgment of their work, and the marginalization or elimination of impairments while promoting mobility and quality of life has been chief among the goals of therapists. That remains the goal still, yet dedicated healthcare professionals who have strengthened and soothed patients for over 100 years aren’t the only option for physicians or patients.

New advances are allowing patients to regain movement through robot-assisted therapy. This includes new technology for patients with decreased range of motion caused by neurological illness or injury, such as stroke, spinal cord injury or brain injury, and those whose motor recovery has stalled.

Stroke patients represent a large faction of those requiring physical therapy. Estimates put the direct and indirect cost of stroke care for the 6.5 million people living with the disability in the US at $73.7 billion,1 a result of its standing as the leading cause of adult disability in Western countries. A majority of these people have impaired upper-limb motor function following stroke and have difficulty performing activities of daily living independently.2

Thus, the need for physical therapy is clear: Studies have shown that only six to 10 percent of people with stroke who have severe paralysis achieve a full recovery by six months,3 and only 18 percent ever regain full UL function.4

Writing in the Journal of Rehabilitation Research and Development,2 Norouzi-Gheidari write that while the initial gradation of stroke and paresis severity predicts UL function recovery well, “task-specific, high-intensity exercises in an active, functional, and highly repetitive manner over a large number of trials have been shown to enhance motor recovery, even in chronic stages of stroke.”

The Latest

Some of the latest advancements in robotic therapy are housed at the Restorative Neurology Clinic at Burke Medical Research Institute in White Plains, New York. Two types of robots under use were designed by Massachusetts Institute of Technology to provide customized, goal-directed therapy aimed at building arm function, strength and re-training of the nerves from the brain to body connection. The first device is the Planar Robot, which focuses on shoulder and elbow function. The other robot is the Wrist Robot, which helps to regain function and strengthen the wrist and forearm. Both machines assist patients with initiation, accuracy, and smoothness of natural movement. As patients’ actions become more accurate and stronger in their movement patterns, the robots will adjust to require the patient to initiate more movement.

Dylan Edwards, PhD, director of the new Restorative Neurology Clinic at Burke Medical Research Institute, described the hardware as a cross between “a fancy exercise machine at the gym and kind of virtual workspace.” The patient’s arm is attached to a joystick and they play a video game on the screen, moving the joystick to hit targets on the screen in front of them.

“They’re sitting playing a difficult video game but the interesting thing about the robotic device is it will sense what they can and cannot do and it will provide assistance accordingly,” he said.

This is important because when a physical therapist instructs a patient to do a particular movement, the patient might not be able to fully complete the task. The therapist would then put their hands on the patient and guide them through the proper motions. “We know that’s very important,” Dr. Edwards said. “They need to be moved through the ranges because that teaches them how to preform the task. That’s a critical ingredient. And as they get better it provides less assistance and they’re required to work more on their own.”

The company says their approach is based on findings from studies in motor function and through collaboration with other medical rehabilitation experts. Dr. Edwards says studies have shown that this form of robotic therapy can lead to significant and meaningful improvements in arm function in patients who have experienced stroke. Using the Fugl-Meyer scale, Dr. Edwards and his team saw patients improve by six points at the Restorative Neurology Clinic at Burke Medical Research Institute. “They get better upper extremity function as a result. There’s now class one, level A evidence as a therapy that was published in Stroke to support the use of this technology,” he said. “We’ve seen them make clinically meaningful gains.”

Indeed, the field of rehabilitation robotics has grown substantially during the past 15 years. Studies of upper limb robot-assisted therapy for adults with moderate to severe hemiparesis after stroke have shown significant gains compared with usual care in isolated control, coordination, and strength in the paretic arm.5 The Stroke study in question said that despite robot-assisted therapy (RT) providing quantifiable, reproducible, interactive, and intensive practice, data on its dose-response relation are scarce; it used two different intensities of the therapy on 54 patients to examine the treatment effects of RT and the effect on outcomes of the severity of initial motor deficits.6 These patients were randomized to a four-week intervention of higher-intensity RT, lower-intensity RT, or control treatment. The primary outcome, the Fugl-Meyer Assessment, was administered at baseline, midterm, and post treatment. The secondary outcomes included the Medical Research Council scale, the Motor Activity Log, and the physical domains of the Stroke Impact Scale.

The authors concluded the study “demonstrated the higher treatment intensity provided by RT was associated with better motor outcome for patients with stroke, which may shape further stroke rehabilitation.”

The higher-intensity RT group showed significantly greater improvements on the Fugl-Meyer Assessment than the lower-intensity RT and control treatment groups at midterm (P=0.003 and P=0.02) and at post treatment (P=0.04 and P=0.02). Within-group gains on the secondary outcomes were significant, but the differences among the 3 groups did not reach significance. Recovery rates of the higher-intensity RT group were higher than those of the lower-intensity RT group, particularly on the Fugl- Meyer Assessment. “Scatterplots with curve fitting showed that patients with moderate motor deficits gained more improvements than those with severe or mild deficits after the higher-intensity RT,” the authors said.

Dr. Edwards concedes robot-assisted therapy likely isn’t a stand-alone treatment. One 2012 study found that when the duration and intensity of conventional therapy (CT) is matched with that of the robot-assisted therapy, “no difference exists between the intensive CT and RT groups in terms of motor recovery, activities of daily living, strength, and motor control.”2 However, depending on the stage of recovery, extra sessions of RT in addition to regular CT are more beneficial than regular CT alone in motor recovery of the hemiparetic shoulder and elbow of patients with stroke. The gains are similar to those that have been observed in intensive CT, the authors noted.

In addition, they argued traditional “hands-on” interventions could, at times, result in repetitive strain injuries and excessive fatigue for therapists, leading to possible failure in delivery of highly intensive and repetitive training.

The authors also point out that all of the findings demonstrate that the effectiveness of rehabilitation robotics is similar to matched CT. Yet they clarify that “when the duration/intensity of conventional rehabilitative care is matched with that of RT, this CT program is not the same as regular, standard care; it is an intensive CT program.”

Though RT did not seem to lead to higher gains in upper-limb function when matched with the same amount of extra CT (intensive CT), employing RT in clinical settings can be justified for several reasons, they said. Due to fatigue or other human-related factors, the therapy might not be the same. For example, during intensive CT, the therapist might not be able to deliver the intensive program as planned and might not adjust it appropriately based on the patient’s progress.

“Regular exercise devices don’t give consideration to the patient’s level of ability and don’t assist the patient as needed,” Dr. Edwards noted of older model machines. “This is a very advanced tool in that it will provide assistance to the patient in a very specific way and back off. So, the difference, really, is that it senses the patient’s capability and provides assistance and support accordingly, and there’s really no other device does that.”

It’s better than a therapist, he said. Unlike a therapist, it provides better repetition. “It tells you any errors you’ve made. And after several hundred repetitions it will provide information on how fast they were moving, how accurate they were moving and both of these kinds of feedback are really important,” he said.

“The main point,” Dr. Edwards said of their new device, “is that this is a promising tool that provides what’s important and necessary for rehabilitation.”

  1. American Heart Association. Heart disease and stroke statistics—2009 Update (At-a-Glance Version) [Internet]. Dallas (TX): American Heart Association; 2009
  2. Norouzi-Gheidari N, Archambault PS, Fung J. Effects of robot-assisted therapy on stroke rehabilitation in upper limbs: systematic review and meta-analysis of the literature. J Rehabil Res Dev. 2012;49(4):479-96.
  3. Wade DT, Hewer RL. Motor loss and swallowing difficulty after stroke: frequency, recovery, and prognosis. Acta Neurol Scand. 1987;76(1):50–54.
  4. Nakayama H, Jørgensen HS, Raaschou HO, Olsen TS. Recovery of upper extremity function in stroke patients: the Copenhagen Stroke Study. Arch Phys Med Rehabil. 1994;75(4):394–98.
  5. Fasoli SE, Ladenheim B, Mast J, Krebs HI. New horizons for robot-assisted therapy in pediatrics. Am J Phys Med Rehabil. 2012 Nov;91(11 Suppl 3)
  6. Hsieh YW, Wu CY, Lin KC, Yao G, Wu KY, Chang YJ. Dose-response relationship of robot-assisted stroke motor rehabilitation: the impact of initial motor status. Stroke. 2012 Oct;43(10):2729-34.

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