Journal of Robotics, Networking and Artificial Life, Vol. 4, No. 1 (June 2017) 53–57___________________________________________________________________________________________________________Clinical Evaluation of UR-System-PARKO for Recovery ofMotor Function of Severe Plegic Hand after Stroke
Hirofumi Tanabe1, Yoshifumi Morita2
12Department of Health Sciences, Shonan University of Medical Sciences,
16-48 Kamishinano, Totsuka-ku,
Yokohama, Kanagawa 244-0806, Japan
E-mail: hirofumi.tanabe@sums.ac.jp

Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology,
Gokiso-cho, Showa-ku,Nagoya, Aichi 466-8555, Japan
E-mail: morita@nitech.ac.jp

AbstractThe first author has developed TANABE therapy for severe hemiplegic stroke patients. In this paper we developed
a training system (UR-System-PARKO) on the basis of TANABE therapy. The clinical test of the therapeutic effectof the UR-System-PARKO was performed in severe plegic hand. The results show the effectiveness of the training
by the UR-System-PARKO for recovery of motor function for finger extension of the severe plegic hand.
Keywords: Training system, Motor function, Finger extension, Spasticity, Hemiplegic stroke patient

1. Introduction

more after the occurrence of the stroke.1,2 However, theseverity of hemiplegia after the stroke was moderate inall patients who recovered motor function in thesereports. More than half of the stroke survivors have asevere plegic hand with difficulty in extending thefingers.3 Therefore, the need for developing a method totreat severe plegic hands is significant.
The first author in an occupational therapist who
developed the TANABE therapy for severe hemiplegicstroke patients. With this therapy, he performed
repeated facilitation training using his hands on patientsto help them recover their motor function, and a goodtreatment outcome was achieved.4 In addition to a bookon this technique, he has trained many therapists5 (Fig.
1). As a result, many therapists have successfully
restored finger movement in patients with severe plegic
hands. This facilitation method increases the output of
the extensor digitorum muscle force through extension

With Japan's gradual advancement towards a so-calledsuperannuated society, the number of people physicallychallenged by disease and by aging is increasing. Thecorresponding increase in the workload of therapists has
become a social issue.
Moreover, according to proposals for health carereform in the rehabilitation field, a system with empiric
treatment for evidence-based medicine (EBM) has to beimplemented. This change will be accelerated byintroducing technology, such as robotics, mechatronics,information processing, and motion control, into therehabilitation exercises administered by therapists inorder to reduce their workload and to improve thetherapeutic effects.
Recently, it has been shown that the motor functionof stroke patients may be restored even six months orCopyright © 2017, the Authors. Published by Atlantis Press.
This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
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Journal of Robotics, Networking and Artificial Life, Vol. 4, No. 1 (June 2017) 53–57___________________________________________________________________________________________________________exercises of the elbow joint while applying resistance tothe tips of the fully extended hemiplegic fingers. In thistype of training, the therapist has to spend a lot of timewith each patient. Therefore, we developed arehabilitation support system (UR-System-PARKO)
designed to reduce the burden on the therapist forresistance training．
The simplified training system previously developedby us for resistance training of hemiplegic upper limbs
was applied to a new support system for the hands. This
simplified training system provides unidirectional
resistance training. We have also developed a brace forsecuring the plegic hand to the apparatus. The objectiveof this study was to verify the effect of training on
increasing the output of the extensor digitorum muscle
force using the UR-System-PARKO on a severe plegichand.

Fig. 1. The author has developed the TANABE therapy forsevere hemiplegic stroke patients.

2.2. Modification of the training system tofacilitate finger extension

2. Training System for Recovery of Motor
Function

In order to improve motor function, especially tofacilitate finger extension, an additional device wasinstalled in the training apparatus. A thermoplastic
splint for fixation was prepared to fix the plegic hand ofa hemiplegic patient in complete extension. Rails werelaid on the arm-fixing plate to allow sliding the splint on
the plate. Rods were set individually to the index,
middle, and ring fingers of the plegic hand, and the hand
was set on the arm-fixing plate so that the patient could
push the arm with her/her fingertips (Fig. 2).

2.1. The previous training system
We developed rehabilitation support systems forresistance training of hemiplegic upper limbs, namely
UR-System 16,7 and UR-System 28. The UR-System 2 isreferred to as the previous training system in this paper.
The previous training system is a force display systemwith one degree-of-freedom that has a mechanicalsystem and a controller. The mechanical system consistsof a brace, a training arm, and a powder brake(SINFONIA TECHNOLOGY CO., Ltd., PRB-2.5H).
The patient moves the training arm by himself/herself.
The brace is attached to the tip of the training arm,
which is used to secure the patient's forearm to theapparatus. The powder brake generates a brake force
that serves as the resistance force during training.
Because this system is not equipped with motors, it isextremely safe and low cost.
In the earlier study9, it was found that the therapist
selectively uses four different resistance patterns duringresistance training. These patterns were detected fromthe movement analysis performed during the manual
training by the therapist using his hands. The four
different resistance patterns, namely a step mode, aslope mode, a wall mode, and a constant mode, areinstalled in the controller. Control programs based onthese results are installed in the controller.

3. Clinical Evaluation of Therapeutic EffectWe conducted clinical tests on patients with severe
chronic plegic hands to verify the therapeutic effects ofthe training with the UR-System-PARKO.
3.1. Assessment
The therapeutic effects of the training with the URSystem-PARKO were assessed by using the surface
electromyogram (EMG), the modified ashworth scale(MAS), and the active range of motion (A-ROM) test.
An EMG electrode pad was applied to the extensor
digitorum muscle, and firing of the extensor digitorum
muscle during exercise was measured. The MAS is oneof the quantitative evaluation methods for spastic
paralysis, which is rated in 6 levels. Level 6 indicatesno increase in muscle tone.
Level 0 indicates that the affected parts are rigid ineither flexion or extension. The A-ROM test is54Journal of Robotics, Networking and Artificial Life, Vol. 4, No. 1 (June 2017) 53–57___________________________________________________________________________________________________________Splint

Push barRail
Arm-fixing plate

Trainingarm(a) Lateral view(b) View from directly above(a) The paralyzed fingers push a lever.

(c) Training(b) The paralyzed forearm pushes a lever.

Fig. 2. UR-System-PARKO.

Fig. 3. Electromyograms of the extensor digitorum muscle
while pushing the lever of the UR-System-PARKO. (Firing
increased when the subject pushed the lever with the fingertipsof the plegic hand compared with that caused by pushing withthe forearm.)

performed to evaluate voluntary motor performance andhas been widely used in clinical settings. The A-ROM ismeasured when a patient moves the joint without any
assistance to the muscles surrounding the joint.

3.3. Method

3.2. Patient

3.3.1. Setting

The subject was a hemiplegic patient in his 40s who had
suffered a stroke 8 years ago. The MAS scorepresenting the grade of spasticity was 3. (He had a moremarked increase in muscle tone through most of theROM, but the affected part (s) easily moved). The
patient did not experience any pain in the training withUR-System-PARKO. The study content was explained
and written consent was obtained from the patient.

The fingers of the patient were set on the splint in thefully extended position followed by fixation to the armof the UR-System-PARKO. First, the therapist tried thetechnique facilitating the extensor digitorum muscle ofthe plegic hand to confirm the exercise initiation andcompletion positions and the grade and timing ofresistance loading.
Then, the subject’s forearm was set on the splint andfixed to the arm-fixing plate of the UR-SystemPARKO. Then, the rods were set to the fingertips of the55

Journal of Robotics, Networking and Artificial Life, Vol. 4, No. 1 (June 2017) 53–57___________________________________________________________________________________________________________

plegic hand to push the lever. The exercise initiation andcompletion positions, resistance value, and initiationand completion positions of resistance loading
confirmed by the therapist beforehand were entered into
the UR-System-PARKO using the operating the panel.
The resistance value was set at 15 N.
3.3.2. Comparison of the output of the extensor
digitorum muscle force between the positionsof applying resistance load
For manual facilitation treatment of the extensor
digitorum muscle, the output of the extensor digitorum
muscle force can be increased by loading resistance on
the fingertips. The position of pushing the UR-SystemPARKO lever was set at 2 sites: 1) the fingertips of theplegic hand and 2) the forearm. The subject pushed theUR-System-PARKO lever against the resistance 10times with each site, and the muscle force output
measured using the EMG was compared between the 2sites.

(a) Before training

3.3.3. Comparison of the active range of motion
and flexor spasticity of the plegic hand
between before and after training with theUR-System-PARKO(b) After training
Fig. 4. Finger extension before and after training.

Training was set so as to load resistance on thefingertips. The subject moved the hand from theinitiation to the completion position and repeated themotion 30 times. A-ROM and MAS were evaluatedbefore initiation and after completion of the exercise
training.

plegic hand after a stroke. The spasticity of the finger
extension is reduced after the training. The A-ROMs ofthe finger extension are expanded after the training.
Our future work is to develop an effective training
method using the UR-System-PARKO whileconsidering factors such as number of repetitions,training days, and so on.
This work was supported by JSPS KAKENHI Grant
Number JP16K01544.

3.3.4. Results and considerations
On comparison of the output of the extensor digitorum
muscle force between the different resistance loading
positions, the muscle force output by pushing the leverwith the fingertips of the plegic hand was greater thanthat by pushing with the forearm on visual observation(Fig. 3). The training with the UR-System-PARKO
increased the A-ROM of the finger extension whencompared with that before training (Fig. 4). The MASof the finger extensors was 2 before training, and it
increased to 4 after training.

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4. Conclusion
A therapeutic effect of the training with the UR-SystemPARKO was shown. The UR-System-PARKO can
improve the motor function of patients with a severe56

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