Association of activity changes in the motor cortex and lower motor neuron with anti-spastic effect of the vibratory stimulation

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K19892
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Nihon Fukushi University
• Principal Investigator: Noma Tomokazu 日本福祉大学, 健康科学部, 教授 (10535793)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 振動刺激 / 筋緊張測定

Outline of Final Research Achievements

In this study, we examined the changes in motor function (muscle strength), cortical excitability and spinal excitability before and after segmental muscle vibration in healthy subjects. Two types of vibration stimulation conditions were set: Condition 1 was an intermediate position of wrist flexion and extension (normal muscle length), and Condition 2 was a wrist extension position (wrist flexor muscles were extended to 40 degrees of dorsiflexion). The results showed that both conditions 1 and 2 increased the strength of the wrist flexor muscles, which are the stimulator muscles, and the wrist extensor muscles, which are the antagonist muscles, respectively, suppressed the excitability of the spinal cord, and increased the excitability of the cerebral cortex. The stimulation under condition 2 tended to have a higher suppressive effect on the spinal cord excitation level than under condition 1.

Free Research Field

神経リハビリテーション

Academic Significance and Societal Importance of the Research Achievements

本研究で開発した振動刺激兼筋力測定装置は安全に再現性も高く刺激や筋力測定ができることがわかった。今回、予備的研究として人体に対する振動刺激の影響を脊髄の興奮性をF波で、大脳皮質の興奮性をfNIRSで測定したが、対象者に共通する傾向を見出すことは難しかった。今回の予備的研究の結果から振動刺激の効果発現メカニズムの仮説や筋を伸長することの優越性は確認できず、健常者や脳卒中片麻痺者を対象とした検証に進む根拠を得たとは言えない。今後は開発した実験装置を使用しながらメカニズム解明の可能性を高める努力を継続したい。