Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Finland.
Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway; Institute of Sports Medicine Copenhagen & Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
J Electromyogr Kinesiol. 2014 Jun;24(3):367-74. doi: 10.1016/j.jelekin.2014.03.002. Epub 2014 Mar 20.
The objective of this study was to investigate the relative contributions of superficial and deep ankle plantarflexors during repetitive submaximal isometric contractions using surface electromyography (SEMG) and positron emission tomography (PET). Myoelectric signals were obtained from twelve healthy volunteers (27.3±4.2yrs). A tracer ([(18)F]-FDG) was injected during the exercise and PET scanning was done immediately afterwards. The examined muscles included soleus (Sol), medial gastrocnemius (MG), lateral gastrocnemius (LG), and flexor hallucis longus (FHL). It was found that isometric maximal voluntary contraction (MVC) force, muscle glucose uptake (GU) rate, and SEMG of various plantarflexors were comparable bilaterally. In terms of %EMG MVC, FHL and MG displayed the highest activity (∼34%), while LG (∼21%) had the lowest activity. Cumulative SEMG from all parts of the triceps surae (TS) muscle accounted for ∼70% of the combined EMG signal of all four plantarflexors. As for GU, the highest quantity was observed in MG (2.4±0.8μmol*100g(-1)min(-1)), whereas FHL (1.8±0.6μmol100g(-1)*min(-1)) had the lowest uptake. Cumulative GU of TS constituted nearly 80% of the combined GU. The findings of this study provide valuable reference for studies where individual muscle contributions are estimated using models and simulations.
本研究旨在通过表面肌电图（SEMG）和正电子发射断层扫描（PET）研究重复亚最大等长收缩时浅层和深层踝关节跖屈肌的相对贡献。我们从 12 名健康志愿者（27.3±4.2 岁）中获得肌电信号。在运动过程中注射示踪剂[（18）F]-FDG，然后立即进行 PET 扫描。检查的肌肉包括比目鱼肌（Sol）、内侧腓肠肌（MG）、外侧腓肠肌（LG）和趾长屈肌（FHL）。结果发现，等长最大自主收缩（MVC）力、肌肉葡萄糖摄取率（GU）和各种跖屈肌的 SEMG 在双侧具有可比性。就 %MVC 而言，FHL 和 MG 显示出最高的活性（约 34%），而 LG（约 21%）的活性最低。小腿三头肌（TS）所有部位的累积 SEMG 占所有四个跖屈肌的总和 EMG 信号的约 70%。至于 GU，MG 观察到的数量最高（2.4±0.8μmol*100g(-1)min(-1)），而 FHL（1.8±0.6μmol100g(-1)*min(-1)）的摄取量最低。TS 的累积 GU 约占总 GU 的 80%。本研究的发现为使用模型和模拟估计单个肌肉贡献的研究提供了有价值的参考。
