caa a22 4500 445353872 CHVBK 20180317142853.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s00221-011-2755-3 doi (NATIONALLICENCE)springer-10.1007/s00221-011-2755-3 Manipulation of a fragile object by elderly individuals [Elektronische Daten] [Stacey Gorniak, Vladimir Zatsiorsky, Mark Latash] We investigated strategies of healthy elderly participants (74-84years old) during prehension and transport of an object with varying degrees of fragility. Fragility was specified as the maximal normal force that the object could withstand without collapsing. Specifically, kinetic and kinematic variables as well as and force covariation indices were quantified and compared to those shown by young healthy persons (19-28years old). We tested three hypotheses related to age-related changes in two safety margins (slip safety margin and crush safety margin) and indices of force covariation. Compared to young controls, elderly individuals exhibited a decrease in object acceleration and an increase in movement time, an increase in grip force production, a decrease in the correlation between grip and load forces, an overall decrease in indices of multi-digit synergies, and lower safety margin indices computed with respect to both dropping and crushing the object. Elderly participants preferred to be at a relatively lower risk of crushing the object even if this led to a higher risk of dropping it. Both groups showed an increase in the index of synergy stabilizing total normal force produced by the four fingers with increased fragility of the object. Age-related changes are viewed as a direct result of physiological changes due to aging, not adaptation to object fragility. Such changes in overall characteristics of prehension likely reflect diminished synergic control by the central nervous system of finger forces with aging. The findings corroborate an earlier hypothesis on an age-related shift from synergic to element-based control. Springer-Verlag, 2011 Prehension nationallicence Fragile object nationallicence Hand nationallicence Biomechanics nationallicence Safety margin nationallicence Elderly nationallicence Gorniak Stacey Department of Biomedical Engineering, Cleveland Clinic, 44195, Cleveland, OH, USA aut Zatsiorsky Vladimir Department of Kinesiology, Rec.Hall-267, The Pennsylvania State University, 16802, University Park, PA, USA aut Latash Mark Department of Kinesiology, Rec.Hall-267, The Pennsylvania State University, 16802, University Park, PA, USA aut Experimental Brain Research Springer-Verlag 212/4(2011-08-01), 505-516 0014-4819 212:4<505 2011 212 221 https://doi.org/10.1007/s00221-011-2755-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2755-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gorniak Stacey Department of Biomedical Engineering, Cleveland Clinic, 44195, Cleveland, OH, USA aut NATIONALLICENCE 700 1- Zatsiorsky Vladimir Department of Kinesiology, Rec.Hall-267, The Pennsylvania State University, 16802, University Park, PA, USA aut NATIONALLICENCE 700 1- Latash Mark Department of Kinesiology, Rec.Hall-267, The Pennsylvania State University, 16802, University Park, PA, USA aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 212/4(2011-08-01), 505-516 0014-4819 212:4<505 2011 212 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 445353872 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer