Article (Scientific journals)
A comparison of voluntary and electrically induced contractions by interleaved H-1- and P-31-NMRS in humans
Vanderthommen, Marc; Duteil, S.; Wary, C. et al.
2003In Journal of Applied Physiology, 94 (3), p. 1012-1024
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Keywords :
muscle metabolism; electrical stimulation; high-energy phosphates; myoglobin oxygenation; human; nuclear magnetic resonance spectroscopy
Abstract :
[en] Skeletal muscle voluntary contractions (VC) and electrical stimulations (ES) were compared in eight healthy men. High-energy phosphates and myoglobin oxygenation were simultaneously monitored in the quadriceps by interleaved H-1- and P-31-NMR spectroscopy. For the VC protocol, subjects performed five or six bouts of 5 min with a workload increment of 10% of maximal voluntary torque (MVT) at each step. The ES protocol consisted of a 13-min exercise with a load corresponding to 10% MVT. For both protocols, exercise consisted of 6-s isometric contractions and 6-s rest cycles. For an identical mechanical level (10% MVT), ES induced larger changes than VC in the P-i-to-phosphocreatine ratio [1.38 +/- 1.14 (ES) vs. 0.13 +/- 0.04 (VC)], pH [6.69 +/- 0.11 (ES) vs. 7.04 +/- 0.07 (VC)] and myoglobin desaturation [43 +/- 15.9 (ES) vs. 6.1 +/- 4.6% (VC)]. ES activated the muscle facing the NMR coil to a greater extent than did VCs when evaluated under identical technical conditions. This metabolic pattern can be interpreted in terms of specific temporal and spatial muscle cell recruitment. Furthermore, at identical levels of energy charge, the muscle was more acidotic and cytoplasm appeared more oxygenated during ES than during VC. These results are in accordance with a preferential recruitment of type II fibers and a relative muscle hyperperfusion during ES.
Disciplines :
Orthopedics, rehabilitation & sports medicine
Anatomy (cytology, histology, embryology...) & physiology
Author, co-author :
Vanderthommen, Marc ;  Université de Liège - ULiège > Département des sciences de la motricité > Kinésithérapie spécifique et réadaptation motrice
Duteil, S.
Wary, C.
Raynaud, J. S.
Leroy-Willig, A.
Crielaard, Jean-Michel ;  Université de Liège - ULiège > Département des sciences de la motricité > Evaluation et entraînement des aptitudes physiques
Carlier, P. G.
Language :
English
Title :
A comparison of voluntary and electrically induced contractions by interleaved H-1- and P-31-NMRS in humans
Publication date :
March 2003
Journal title :
Journal of Applied Physiology
ISSN :
8750-7587
eISSN :
1522-1601
Publisher :
Amer Physiological Soc, Bethesda, United States - Maryland
Volume :
94
Issue :
3
Pages :
1012-1024
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 19 May 2009

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