The effect of voluntary muscle contraction on spinal cord excitability and its application for rehabilitation medicine

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K01461
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Rehabilitation science/Welfare engineering
• Research Institution: Teikyo University (2020); Saitama Medical University (2018-2019); Saitama Prefectural University (2017)
• Principal Investigator: HARA MOTOHIKO 帝京大学, 医学部, 教授 (30386007)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 脊髄興奮性 / F波

Outline of Final Research Achievements

We examined the effect on ulnar F-wave persistence and amplitude which indicated spinal cord excitability by neck rotation, neck anterior flexion and teeth clenching. We examined the effect of motor imagery (MI) and voluntary muscle contraction (VC) of teeth clinching on the persistence and amplitude of F-waves recorded from the FDI before and immediately after transcranial direct stimulation (tDCS). Neck rotation and anterior flexion showed that F wave persistence and amplitude are increased at rest from VC respectively. Both motor imagery and VC of teeth clenching enhanced F-wave persistence and amplitude of FDI. The anodal tDCS had no influence on such excitability change. In conclusion, our studies show that spinal cord excitability may enhance by MI and VC of different part. Farther discussion needs for the effect of anodal tDCS for motor tasks and spinal cord excitability in F-wave study.

Free Research Field

リハビリテーション医学

Academic Significance and Societal Importance of the Research Achievements

今回の研究では、脊髄興奮性の指標の一つであるF波が、F波を記録しているのとは異なる筋の軽度の随意収縮や運動想起を行うことで尺骨神経を刺激して第一背側骨間筋から記録したF波の出現率と振幅が安静時に較べてどのように変化するかを検討した。頚部の回旋、前屈、Teeth clenchingのいずれにおいてもF波の出現率と振幅が安静時に較べて運動想起と軽度随意収縮を行うことによって増加する所見を認めた。この結果はギプス固定などで上肢の安静を余儀なくされる状態および下位頚髄損傷の状態でも、頚部と咬筋の運動想起と軽度随意的筋収縮により異なる髄節支配部位の脊髄興奮性を維持できる可能性を示唆している。