caa a22 4500 445811641 CHVBK 20180317145213.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00419-010-0458-z doi (NATIONALLICENCE)springer-10.1007/s00419-010-0458-z Human leg impact: energy dissipation of wobbling masses [Elektronische Daten] [Syn Schmitt, Michael Günther] In terrestrial locomotion, the soft-tissue masses of the body undergo damped oscillations following leg impacts with the ground. Appropriate biomechanical models, therefore, describe gross soft-tissue dynamics by "wobbling masses”. We calculated mechanical energy balances of shank and thigh wobbling masses of the stance leg for the first 90ms after touch-down in human heel-toe running. Thereto, we re-visited a data set on wobbling mass kinematics which had formerly been gained non-invasively by acquiring the motion of grids of lines painted on the skin of the corresponding muscle masses with high-speed cameras. We found frequencies ranging from 3Hz to 55Hz and maximum wobbling mass excursions relative to the bone ranging from 3mm to 4cm for the centres of mass and from 2.2° to 11.4° for the rotations. The rotational energy balance is practically neutral (±1J). Usually, there is clearly more energy that is dissipated by wobbling mass movement in horizontal (thigh: <50J) than in vertical direction (thigh: <15J). There is less energy dissipated in the shank (horizontal: <10J, vertical: <5J). We argue that the energetic costs of separating significant wobbling masses from the skeleton may be over-compensated by avoiding metabolic costs of active impact reduction and by decreasing loads on passive skeletal structures, in particular when distal leg masses are functional, as in humans. Within reasonable biological limits, impacts are known to be even necessary for structural strengthening of bones. Beyond that, impacts might also be useful for stabilising locomotion, both by increasing basins of attraction and by providing simple mechanical signals for control. Springer-Verlag, 2010 Biomechanics nationallicence Locomotion nationallicence Human running nationallicence Soft tissue nationallicence Experimental analysis nationallicence Schmitt Syn Institut für Sport- und Bewegungswissenschaft, Universität Stuttgart, Allmandring 28, 70569, Stuttgart, Germany aut Günther Michael Institut für Sport- und Bewegungswissenschaft, Universität Stuttgart, Allmandring 28, 70569, Stuttgart, Germany aut Archive of Applied Mechanics Springer-Verlag 81/7(2011-07-01), 887-897 0939-1533 81:7<887 2011 81 419 https://doi.org/10.1007/s00419-010-0458-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00419-010-0458-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schmitt Syn Institut für Sport- und Bewegungswissenschaft, Universität Stuttgart, Allmandring 28, 70569, Stuttgart, Germany aut NATIONALLICENCE 700 1- Günther Michael Institut für Sport- und Bewegungswissenschaft, Universität Stuttgart, Allmandring 28, 70569, Stuttgart, Germany aut NATIONALLICENCE 773 0- Archive of Applied Mechanics Springer-Verlag 81/7(2011-07-01), 887-897 0939-1533 81:7<887 2011 81 419 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer