Intramuscular Pressure of Tibialis Anterior Reflects Ankle Torque but Does Not Follow Joint Angle-Torque Relationship
Autor: | Brenda L. Davies, Kenton R. Kaufman, Krista Coleman-Wood, Filiz Ateş, William J. Litchy, Swati Chopra |
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Jazyk: | angličtina |
Rok vydání: | 2018 |
Předmět: |
electromyography
Physiology 0206 medical engineering force prediction 02 engineering and technology Isometric exercise Electromyography electromechanical delay lcsh:Physiology 03 medical and health sciences 0302 clinical medicine Tibialis anterior muscle Physiology (medical) Medicine Torque fine-wire EMG Intramuscular pressure Original Research 2. Zero hunger medicine.diagnostic_test lcsh:QP1-981 business.industry tibialis anterior 020601 biomedical engineering Electrophysiology medicine.anatomical_structure intramuscular pressure Ankle business surface EMG 030217 neurology & neurosurgery Ankle torque Biomedical engineering |
Zdroj: | Frontiers in Physiology, Vol 9 (2018) Frontiers in Physiology |
ISSN: | 1664-042X |
Popis: | Intramuscular pressure (IMP) is the hydrostatic fluid pressure that is directly related to muscle force production. Electromechanical delay (EMD) provides a link between mechanical and electrophysiological quantities and IMP has potential to detect local electromechanical changes. The goal of this study was to assess the relationship of IMP with the mechanical and electrical characteristics of the tibialis anterior muscle (TA) activity at different ankle positions. We hypothesized that (1) the TA IMP and the surface EMG (sEMG) and fine-wire EMG (fwEMG) correlate to ankle joint torque, (2) the isometric force of TA increases at increased muscle lengths, which were imposed by a change in ankle angle and IMP follows the length-tension relationship characteristics, and (3) the electromechanical delay (EMD) is greater than the EMD of IMP during isometric contractions. Fourteen healthy adults [7 female; mean (SD) age = 26.9 (4.2) years old with 25.9 (5.5) kg/m(2) body mass index] performed (i) three isometric dorsiflexion (DF) maximum voluntary contraction (MVC) and (ii) three isometric DF ramp contractions from 0 to 80% MVC at rate of 15% MVC/second at DF, Neutral, and plantarflexion (PF) positions. Ankle torque, IMP, TA fwEMG, and TA sEMG were measured simultaneously. The IMP, fwEMG, and sEMG were significantly correlated to the ankle torque during ramp contractions at each ankle position tested. This suggests that IMP captures in vivo mechanical properties of active muscles. The ankle torque changed significantly at different ankle positions however, the IMP did not reflect the change. This is explained with the opposing effects of higher compartmental pressure at DF in contrast to the increased force at PF position. Additionally, the onset of IMP activity is found to be significantly earlier than the onset of force which indicates that IMP can be designed to detect muscular changes in the course of neuromuscular diseases impairing electromechanical transmission. |
Databáze: | OpenAIRE |
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