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A. Hiraga1, T. Kimura2, S. Tanabe3, K. Sugawara4
1Teikyo University of Science, Department of Physical Therapy, Faculty of Medical Sciences, Uenohara, Yamanashi, Japan, 2Tsukuba International University, Department of Physical Therapy, Faculty of Health Sciences, Tsuchiura, Ibaraki, Japan, 3Fujita Health University, Faculty of Rehabilitation, School of Health Sciences, Toyoake, Aichi, Japan, 4Kanagawa University of Human Services, Graduate Course of Health and Social Service, Yokosuka, Kanagawa, Japan
Background: Improvement in motor paralysis caused by stroke influences smooth resumption of daily life. Therefore, relearning motor behavior is important to achieve these objectives during rehabilitation. However, in physical therapy, voluntary movement should be active; when active enforcement is not possible, electrical stimulation is used. Few studies report the effect of exercise using voluntary movement and electrical stimulation, in healthy or paralyzed individuals.
Purpose: This study aimed to verify the effectiveness and method of stimulation for change in performance when both electric stimulation and voluntary repetitive movements were used for motor learning.
Methods: We performed two experiments with a total of 50 subjects. Experiment 1 used a combination effect. The motor task comprised extending the left wrist, while the tracking task comprised following the dot marker, which moved up and down with the extension force of the wrist joint to show a baseline waveform on the PC display. In this study, electrical stimulation (ES) of fixed intensity and voluntary movement (Vol) were combined; the subjects were divided into three groups of 10: ES+ Vol practicing group (Hybrid group), ES-only practicing group (ES group), and Vol-only practicing group (Vol group). The exercise was repeated 11 times to make one set, which was repeated for a total of five sets. For the test session, the tracking task without visual feedback was performed 10 times before and after the practice, and the error area between the baseline and the indicated marker tracking line was calculated and compared. Experiment 2 involved examination of electrical stimulation that changed according to the baseline waveform when used with ES and Vol. The motor task and experimental protocol were the same as in Experiment 1. Ten subjects participated in each of the following two practice conditions:
1) step-by-step change in ES strength according to the tracking waveform (Variable group) and
2) constant ES (Constant group). In experiment 2, in addition to the total error area, the percentage of the marker tracking line in the range of 10% above and below the baseline was calculated as the fit rate. The two-way ANOVA (significance level 5%) was used for statistical analysis of the total error area, fit rate time factors, and practice condition factors.
1) step-by-step change in ES strength according to the tracking waveform (Variable group) and
2) constant ES (Constant group). In experiment 2, in addition to the total error area, the percentage of the marker tracking line in the range of 10% above and below the baseline was calculated as the fit rate. The two-way ANOVA (significance level 5%) was used for statistical analysis of the total error area, fit rate time factors, and practice condition factors.
Results: The error area of the Hybrid group in Experiment 1 showed significant decrease after practice, while, in Experiment 2, no difference in the factors of the practice conditions. The fit rate was increased significantly after practice in the Variable group.
Conclusion(s): Thus, a combination of ES and Vol was effective and it was presumed that the output amount was fine-tuned during enforcement using an electrical stimulus that grew strong in tune with the waveform using feedback information.
Implications: A combination of ES and Vol would be useful for motor learning using tracking tasks that require step-by-step force output adjustment. It would be more effective to change the ES stimulus intensity according to the task.
Funding, acknowledgements: This study was funded by Grant-in-Aid for Scientific Research (KAKENHI).
Keywords: Electrical Stimulation, Combined Effect, Motor Learning
Topic: Electrophysical & isothermal agents
Did this work require ethics approval? Yes
Institution: Kanagawa University of Human Services
Committee: Research Ethics Committee
Ethics number: No.71-60
All authors, affiliations and abstracts have been published as submitted.
