Objective: To determine the efficacy of a stretching and strengthening exercise program using an upper extremity robot, as compared with a conventional occupational therapy program for upper extremity spasticity in stroke patients.
Methods: Subjects were randomly divided into a robot-assisted therapy (RT) group and a conventional rehabilitation therapy (CT) group. RT group patients received RT and CT once daily for 30 minutes each, 5 days a week, for 2 weeks. RT was performed using an upper-extremity robot (Neuro-X; Apsun Inc., Seoul, Korea), and CT was administered by occupational therapists. CT group patients received CT alone twice daily for 30 minutes, 5 days a week, for 2 weeks. Modified Ashworth Scale (MAS) was used to measure the spasticity of upper extremity. Manual muscle tests (MMT), Manual Function Tests (MFT), Brunnstrom stage, and the Korean version of Modified Barthel Index (K-MBI) were used to measure the strength and function of upper extremity. All measurements were obtained before and after 2-week treatment.
Results: The RT and CT groups included 22 subjects each. After treatment, both groups showed significantly lower MAS scores and significant improvement in the MMT, MFT, Brunnstrom stage, and K-MBI scores. Treatment effects showed no significant differences between the two groups.
Conclusion: RT showed similar treatment benefits on spasticity, as compared to CT. The study results suggested that RT could be a useful method for continuous, repeatable, and relatively accurate range of motion exercise in stroke patients with spasticity.
Spasticity is defined as a velocity-dependent increase in tonic stretch reflex, resulting from over-excitation of the stretch reflex due to upper motor neuron lesions . It occurs frequently in patients with post-stroke hemiplegia. Excessive spasticity reduces patients’ range of motion (ROM) to the extent that it obstructs daily living activities and functional improvement, thereby adversely affecting successful rehabilitation.
Various treatment methods are used to control spasticity, such as exercise, drug therapy, electrostimulation, surgery, and local nerve block using botulinum toxin [2, 3, 4, 5]. Conventional rehabilitation therapy for spasticity administered by therapists includes passive stretching and ROM exercise treatment. The amount and effects of repetitive exercise manually induced by therapists may differ according to the therapists’ levels of experience .
In recent decades, rehabilitation treatment using a robot has been developed to reproduce accurate motions repeatedly with less input of physical effort and time by therapists. Upper extremity rehabilitation treatment using robots has been available since the 1990s and the clinical effects on upper extremity function recovery are reported.
Studies on robotic assisted rehabilitation therapy in stroke patients have shown significant improvement in motor abilities of the exercised limb and enhanced functional outcomes [7, 8, 9, 10, 11]. However, some studies indicated that when the duration and intensity of conventional treatment is matched with robotic treatment, motor recovery, activities of daily living, strength, and motor control show no group-wise differences . Nevertheless, additional sessions of robotic treatment promote better motor recovery in patients with stroke, as compared with additional conventional treatment .
Previously, studies indicated variable treatment effects of robot-assisted rehabilitation treatment on upper extremity spasticity. Fazekas et al.  reported significant change in Modified Ashworth Score (MAS) of shoulder adductors and elbow flexor only in the robotic treatment group. However, it reportedly has a small, non-significant effect on muscle tone based on MAS in other studies [10, 11, 14].
The aim of the present study was to evaluate the effect of upper extremity rehabilitation robots on spasticity in stroke patients. We conducted a randomized controlled trial to evaluate upper extremity spasticity, motor power and functions in response to therapy.