caa a22 4500 467941424 CHVBK 20180406153013.0 cr unu---uuuuu 170328e20060101xx s 000 0 eng 10.1007/s00421-004-1211-5 doi (NATIONALLICENCE)springer-10.1007/s00421-004-1211-5 Surface mechanomyogram amplitude is not attenuated by intramuscular pressure [Elektronische Daten] [K. Søgaard, C. Orizio, G. Sjøgaard] The electromyogram (EMG) and intramuscular pressure (IMP) increase linearly with force during voluntary static contractions, while the surface mechanomyogram (MMG) increases linearly only up to approximately 70% of the maximal voluntary contraction (MVC) and then levels off. The aim of this study was to investigate the possible influence of IMP on the non-linear MMG increase with force and hence on the signal generation process. Seven subjects performed static contractions of the elbow flexors during: (1) ramp contractions from 0 to 60% of the MVC, and (2) steps at 10, 20 and 40% of the MVC. An external pressure of 0 and 50mmHg for the ramps or 0, 20, 40, 60, 80 and 100 mmHg for the steps was applied by means of a sphygmomanometer cuff in separate trials. The EMG and the MMG were detected in the biceps brachii by means of a pair of surface electrodes and an accelerometer. The IMP was measured using a Millar tipped pressure transducer, and the data was presented as the mean and standard deviation in each case. The IMP was strongly and linearly related to the external pressure and contraction force both during ramps and steps. The EMGrms and MMGrms were never reduced as a consequence of the IMP increments. In contrast, a steeper MMGrms versus %MVC relationship during ramps at 50mmHg cuff pressure, and an influence of the cuff pressure at 40% of MVC on MMGrms were evident. We conclude that IMP per se does not attenuate the MMG generation process during voluntary contraction, suggesting that the previously described MMGrms decrease at near maximal static efforts must be attributed to other determinants, such as a fusion-like situation due to the high motor unit firing rate. Springer-Verlag, 2004 Mechanomyogram nationallicence Intramuscular pressure nationallicence Electromyogram nationallicence Static voluntary contraction nationallicence Biceps brachii nationallicence Søgaard K. Department of Physiology, National Institute of Occupational Health, Copehangen, Denmark aut Orizio C. Dipartimento Scienze Biomediche e Biotecnologie, Università degli Studi di Brescia, Viale Europa 11, 25123, Brescia, Italy aut Sjøgaard G. Department of Physiology, National Institute of Occupational Health, Copehangen, Denmark aut European Journal of Applied Physiology Springer-Verlag 96/2(2006-01-01), 178-184 1439-6319 96:2<178 2006 96 421 https://doi.org/10.1007/s00421-004-1211-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-004-1211-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Søgaard K. Department of Physiology, National Institute of Occupational Health, Copehangen, Denmark aut NATIONALLICENCE 700 1- Orizio C. Dipartimento Scienze Biomediche e Biotecnologie, Università degli Studi di Brescia, Viale Europa 11, 25123, Brescia, Italy aut NATIONALLICENCE 700 1- Sjøgaard G. Department of Physiology, National Institute of Occupational Health, Copehangen, Denmark aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/2(2006-01-01), 178-184 1439-6319 96:2<178 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer