caa a22 4500 467941742 CHVBK 20180406153014.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s00421-006-0241-6 doi (NATIONALLICENCE)springer-10.1007/s00421-006-0241-6 Strength, size and activation of knee extensors followed during 8weeks of horizontal bed rest and the influence of a countermeasure [Elektronische Daten] [E. Mulder, D. Stegeman, K. Gerrits, M. Paalman, J. Rittweger, D. Felsenberg, A. de Haan] Changes in the quadriceps femoris muscle with respect to anatomical cross sectional area (CSA), neural activation level and muscle strength were determined in 18 healthy men subjected to 8weeks of horizontal bed rest (BR) with (n=9) and without (n=9) resistive vibration exercise (RVE). CSA of the knee extensor muscle group was measured with magnetic resonance imaging every 2weeks during bed rest. In the control subjects (Ctrl), quadriceps femoris CSA decreased linearly over the 8weeks of bed rest to −14.1±5.2% (P<0.05). This reduction was significantly (P<0.001) mitigated by the exercise paradigm (−3.5±4.2%; P<0.05). Prior to and seven times during bed rest, maximal unilateral voluntary torque (MVT) values of the right leg were measured together with neural activation levels by means of a superimposed stimulation technique. For Ctrl, MVT decreased also linearly over time to −16.8±7.4% after 8weeks of bed rest (P<0.01), whereas the exercise paradigm fully maintained MVT during bed rest. In contrast to previous reports, the maximal voluntary activation remained unaltered for both groups throughout the study. For Ctrl, the absence of deterioration of the activation level might have been related to the repeated testing of muscle function during the bed rest. This notion was supported by the observation that for a subset of Ctrl subjects (n=5) the MVT of the left leg, which was not tested during BR, was reduced by 20.5±10.1%, (P<0.01) which was for those five subjects significantly (P<0.05) more than the 11.1±9.2% (P<0.01) reduction for the right, regularly tested leg. Springer-Verlag, 2006 bed rest nationallicence Maximum voluntary torque nationallicence Voluntary activation nationallicence Atrophy nationallicence Countermeasure nationallicence Mulder E. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut Stegeman D. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut Gerrits K. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut Paalman M. Faculty of Human Movement Sciences, Vrije University, Amsterdam, The Netherlands aut Rittweger J. Center for Muscle and Bone research, Charité-Campus Benjamin Franklin, Berlin, Germany aut Felsenberg D. Center for Muscle and Bone research, Charité-Campus Benjamin Franklin, Berlin, Germany aut de Haan A. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut European Journal of Applied Physiology Springer-Verlag 97/6(2006-08-01), 706-715 1439-6319 97:6<706 2006 97 421 https://doi.org/10.1007/s00421-006-0241-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-006-0241-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mulder E. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Stegeman D. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Gerrits K. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Paalman M. Faculty of Human Movement Sciences, Vrije University, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Rittweger J. Center for Muscle and Bone research, Charité-Campus Benjamin Franklin, Berlin, Germany aut NATIONALLICENCE 700 1- Felsenberg D. Center for Muscle and Bone research, Charité-Campus Benjamin Franklin, Berlin, Germany aut NATIONALLICENCE 700 1- de Haan A. Institute for Fundamental and Clinical Human Movement Sciences, Amsterdam, The Netherlands aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 97/6(2006-08-01), 706-715 1439-6319 97:6<706 2006 97 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer