Biceps brachii muscle oxygenation in electrical muscle stimulation.
The purpose of this study was to compare between electrical muscle stimulation (EMS) and maximal voluntary (VOL) isometric contractions of the elbow flexors for changes in biceps brachii muscle oxygenation (tissue oxygenation index, TOI) and haemodynamics (total haemoglobin volume, tHb = oxygenated-Hb + deoxygenated-Hb) determined by near-infrared spectroscopy (NIRS). The biceps brachii muscle of 10 healthy men (23-39 years) was electrically stimulated at high frequency (75 Hz) via surface electrodes to evoke 50 intermittent (4-s contraction, 15-s relaxation) isometric contractions at maximum tolerated current level (EMS session). The contralateral arm performed 50 intermittent (4-s contraction, 15-s relaxation) maximal voluntary isometric contractions (VOL session) in a counterbalanced order separated by 2-3 weeks. Results indicated that although the torque produced during EMS was approximately 50% of VOL (P<0.05), there was no significant difference in the changes in TOI amplitude or TOI slope between EMS and VOL over the 50 contractions. However, the TOI amplitude divided by peak torque was approximately 50% lower for EMS than VOL (P<0.05), which indicates EMS was less efficient than VOL. This seems likely because of the difference in the muscles involved in the force production between conditions. Mean decrease in tHb amplitude during the contraction phases was significantly (P<0.05) greater for EMS than VOL from the 10th contraction onwards, suggesting that the muscle blood volume was lower in EMS than VOL. It is concluded that local oxygen demand of the biceps brachii sampled by NIRS is similar between VOL and EMS.
Muthalib
Makii
M
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Australia.|Institute of Health and Biomedical Innovation & School of Human Movement Studies, Queensland University of Technology, Brisbane, Australia.
Jubeau
Marc
M
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Australia.|Laboratory INSERM U887, Faculty of Sport Sciences, University of Burgundy, Dijon, France.
Millet
Guillaume Y
GY
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Australia.|Exercise Physiology Laboratory, Jean Monnet University, Saint-Etienne, France.
Maffiuletti
Nicola A
NA
Neuromuscular Research Laboratory, Schulthess Clinic, Zürich, Switzerland.
Ferrari
Marco
M
Department of Health Sciences, University of L'Aquila, L'Aquila, Italy.
Nosaka
Kazunori
K
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Australia.
D000328:Adult; D004558:Electric Stimulation; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation* / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010108:Oxyhemoglobins / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared; D019415:Torque; D034941:Upper Extremity; D055815:Young Adult
D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen