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Differential contributions of ankle plantarflexors during submaximal isometric muscle action: A PET and EMG study

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Tahir Masood
  • Jens Bojsen-Møller
  • Kari K Kalliokoski
  • Anna Kirjavainen
  • Ville Áärimaa
  • S Peter Magnusson
  • Taija Finni
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±0.6μmol*100g(-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.
OriginalsprogEngelsk
TidsskriftJournal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology
Vol/bind24
Udgave nummer3
Sider (fra-til)367–374
Antal sider8
ISSN1050-6411
DOI
StatusUdgivet - jun. 2014

ID: 138553865