caa a22 4500 469055227 CHVBK 20180323132841.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF00843767 doi (NATIONALLICENCE)springer-10.1007/BF00843767 Oxygen availability and motor unit activity in humans [Elektronische Daten] [Toshio Moritani, W. Sherman, Masashi Shibata, Tamaki Matsumoto, Minoru Shinohara] Summary: Six men were studied to determine the interrelationships among blood supply, motor unit (MU) activity and lactate concentrations during intermittent isometric contractions of the hand grip muscles. The subjects performed repeated contractions at 20% of maximal voluntary contraction (MVC) for 2 s followed by 2-s rest for 4 min with either unhindered blood circulation or arterial occlusion given between the 1st and 2nd min. The simultaneously recorded intramuscular MU spikes and surface electromyogram (EMG) data indicated that mean MU spike amplitude, firing frequency and the parameters of surface EMG power spectra (mean power frequency and root mean square amplitude) remained constant during the experiment with unhindered circulation, providing no electrophysiological signs of muscle fatigue. Significant increases in mean MU spike amplitude and frequency were, however, evident during the contractions with arterial occlusion. Similar patterns of significant changes in the surface EMG spectra parameters and venous lactate concentration were also observed, while the integrated force-time curves remained constant. These data would suggest that the metabolic state of the active muscles may have played an important role in the regulation of MU recruitment and rate coding patterns during exercise. Springer-Verlag, 1992 Motor unit nationallicence Recruitment nationallicence Rate coding nationallicence Metabolism nationallicence Electromyogram frequency power spectra nationallicence Moritani Toshio Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut Sherman W. School of Health, Physical Education and Recreation, Ohio State University, 43210, Columbus, OH, USA aut Shibata Masashi Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut Matsumoto Tamaki Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut Shinohara Minoru Department of Health and Physical Education, Kyoto College of Art, 606, Kyoto, Japan aut European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 64/6(1992-11-01), 552-556 0301-5548 64:6<552 1992 64 421 https://doi.org/10.1007/BF00843767 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00843767 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Moritani Toshio Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut NATIONALLICENCE 700 1- Sherman W. School of Health, Physical Education and Recreation, Ohio State University, 43210, Columbus, OH, USA aut NATIONALLICENCE 700 1- Shibata Masashi Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut NATIONALLICENCE 700 1- Matsumoto Tamaki Laboratory of Applied Physiology, College of Liberal Arts and Sciences, Kyoto University, Sakyo-ku, 606, Kyoto, Japan aut NATIONALLICENCE 700 1- Shinohara Minoru Department of Health and Physical Education, Kyoto College of Art, 606, Kyoto, Japan aut NATIONALLICENCE 773 0- European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 64/6(1992-11-01), 552-556 0301-5548 64:6<552 1992 64 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer