作者: Kasper B. Christensen , Michael Günther , Syn Schmitt , Tobias Siebert
DOI: 10.1038/S41598-017-13630-7
关键词: Work (physics) 、 Isometric exercise 、 Skeletal muscle 、 Strain (injury) 、 Stiffness 、 Shock (mechanics) 、 Mechanics 、 Eccentric 、 Mechanical energy 、 Materials science
摘要: In terrestrial locomotion, muscles undergo damped oscillations in response to limb impacts with the ground. Muscles are also actuators that generate mechanical power allow locomotion. The corresponding elementary contractile process is work stroke of an actin-myosin cross-bridge, which may be forcibly detached by superposed oscillations. By experimentally emulating rat leg impacts, we found full activity and non-fatigue must meet possibly prevent forcible cross-bridge detachment. Because submaximal muscle force represents ordinary locomotor condition, our results show forcible, eccentric detachment a common, physiological even during isometric contractions. We calculated stiffnesses whole muscle-tendon complex fibre material separately, as well Young’s modulus latter: 1.8 MPa 0.75 MPa for fresh, fully active passive fibres, respectively. Our inferred tendon-aponeurosis suggests stiffness series determined elastic properties aponeurosis region, rather than tendon material. Knowing these mass, complex’ eigenfrequency responses can quantified, size-dependency this time scale muscular wobbling mass dynamics.