caa a22 4500 445353694 CHVBK 20180317142852.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00221-011-2753-5 doi (NATIONALLICENCE)springer-10.1007/s00221-011-2753-5 Effects of plantar-flexor muscle fatigue on the magnitude and regularity of center-of-pressure fluctuations [Elektronische Daten] [Melvyn Roerdink, Petra Hlavackova, Nicolas Vuillerme] Control of bipedal posture is highly automatized but requires attentional investment, the amount of which varies between participants and with postural constraints, such as plantar-flexor muscle fatigue. Elevated attentional demands for standing with fatigued plantar flexors have been demonstrated using a stimulus-response reaction-time paradigm. Recently, a direct relation between the regularity of center-of-pressure (COP) fluctuations and the amount of attention invested in posture was proposed, according to which more regular COP fluctuations are expected with muscle fatigue than without. To study this prediction, we registered anterior-posterior COP fluctuations for bipedal stance with eyes closed prior to and after a plantar-flexor muscle fatiguing exercise protocol in 16 healthy young adults. We quantified the magnitude of COP fluctuations with conventional posturography and its regularity with sample entropy. The magnitude of COP fluctuations increased significantly with fatigued plantar flexors. In addition, more regular COP fluctuations were observed with fatigued plantar flexors, as evidenced by significantly lower sample entropy values. These findings corroborated our hypotheses. Moreover, COP regularity assisted in qualifying the change in sway magnitude with fatigue. Whereas increased sway is customary taken to reflect impaired postural control, we interpret it as a functional, but attention-demanding adaptation to the alteration of important posture-specific information. The Author(s), 2011 Postural control nationallicence Attentional investment nationallicence Center-of-pressure regularity nationallicence Muscle fatigue nationallicence Roerdink Melvyn Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands aut Hlavackova Petra FRE 3405, AGIM (AGeing, Imaging, Modelling) CNRS-UJF-EPHE, AFIRM team, Grenoble, France aut Vuillerme Nicolas FRE 3405, AGIM (AGeing, Imaging, Modelling) CNRS-UJF-EPHE, AFIRM team, Grenoble, France aut Experimental Brain Research Springer-Verlag 212/3(2011-07-01), 471-476 0014-4819 212:3<471 2011 212 221 https://doi.org/10.1007/s00221-011-2753-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2753-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Roerdink Melvyn Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Hlavackova Petra FRE 3405, AGIM (AGeing, Imaging, Modelling) CNRS-UJF-EPHE, AFIRM team, Grenoble, France aut NATIONALLICENCE 700 1- Vuillerme Nicolas FRE 3405, AGIM (AGeing, Imaging, Modelling) CNRS-UJF-EPHE, AFIRM team, Grenoble, France aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 212/3(2011-07-01), 471-476 0014-4819 212:3<471 2011 212 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer