caa a22 4500 467940681 CHVBK 20180406153011.0 cr unu---uuuuu 170328e20060401xx s 000 0 eng 10.1007/s00421-005-0124-2 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0124-2 Effects of the transition time between muscle-tendon stretch and shortening on mechanical efficiency [Elektronische Daten] [Yves Henchoz, Davide Malatesta, Gérald Gremion, Alain Belli] The net mechanical efficiency of positive work (ηpos) has been shown to increase if it is immediately preceded by negative work. This phenomenon is explained by the storage of elastic energy during the negative phase and its release during the subsequent positive phase. If a transition time (T) takes place, the elastic energy is dissipated into heat. The aim of the present study was to investigate the relationship between ηpos and T, and to determine the minimal T required so that ηpos reached its minimal value. Seven healthy male subjects were tested during four series of lowering-raising of the body mass. In the first series (S 0), the negative and positive phases were executed without any transition time. In the three other series, T was varied by a timer (0.12, 0.24 and 0.56s for series S 1, S 2 and S 3, respectively). These exercises were performed on a force platform sensitive to vertical forces to measure the mechanical work and a gas analyser was used to determine the energy expenditure. The results indicated that ηpos was the highest (31.1%) for the series without any transition time (S 0). The efficiencies observed with transition times (S 1, S 2 and S 3) were 27.7, 26.0 and 23.8%, respectively, demonstrating that T plays an important role for mechanical efficiency. The investigation of the relationship between ηpos and T revealed that the minimal T required so that ηpos reached its minimal value is 0.59s. Springer-Verlag, 2006 Mechanical efficiency nationallicence Elastic energy nationallicence Transition time nationallicence Stretch-shortening cycle nationallicence Henchoz Yves Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut Malatesta Davide Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut Gremion Gérald University Hospital for Orthopaedic Surgery, Lausanne, Switzerland aut Belli Alain Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut European Journal of Applied Physiology Springer-Verlag 96/6(2006-04-01), 665-671 1439-6319 96:6<665 2006 96 421 https://doi.org/10.1007/s00421-005-0124-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0124-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Henchoz Yves Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut NATIONALLICENCE 700 1- Malatesta Davide Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut NATIONALLICENCE 700 1- Gremion Gérald University Hospital for Orthopaedic Surgery, Lausanne, Switzerland aut NATIONALLICENCE 700 1- Belli Alain Institut des Sciences du Sport et de l'Education Physique, Université de Lausanne, Bâtiment Provence, 1015, Lausanne, Switzerland aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/6(2006-04-01), 665-671 1439-6319 96:6<665 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence SWISSBIB 324601468 BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer