... on living tissue. Therefore, in this study we conducted in situ work-loop experiments on rat plantaris muscle to determine the effects of increasing the mass of muscle on mechanical work during cyclic contractions. We additionally simulated these experimental contractions using a mass-enhanced Hill-type...

... of sprint running (i.e. over 50 m from the start). Using these data, the external mechanical work done was calculated for each step. They found the total external mechanical work done during the braking phase of the step to increase by at least 4.6-fold over the whole acceleration stage, whereas...

...Dominic James Farris; Brent James Raiteri ABSTRACT Humans and other cursorial mammals have distal leg muscles with high in-series compliance that aid locomotor economy. This muscle–tendon design is considered sub-optimal for injecting net positive mechanical work. However, humans change speed...

...Brian P. Selgrade; Montakan Thajchayapong; Gloria E. Lee; Megan E. Toney; Young-Hui Chang ABSTRACT Minimizing whole-body metabolic cost has been suggested to drive the neural processes of locomotor adaptation. Mechanical work performed by the legs should dictate the major changes in whole-body...

... during locomotion in the human musculoskeletal system . Science   265 , 651 - 653 . 10.1126/science.8036513 Cavagna , G. A. and Kaneko , M. ( 1977 ). Mechanical work and efficiency in level walking and running . J. Physiol.   268 , 467 - 481 . 10.1113/jphysiol.1977.sp011866...

.... Mechanical work against the external environment was 0.87 J m −1 kg −1 for DS, 0.70 J m −1 kg −1 for DP and 0.79 J m −1 kg −1 for DK. The work done to overcome frictional forces, which is negligible in walking and running, was 17.8%, 32.3% and 24.8% of external mechanical work for DS, DP and DK, respectively...

... ). This is accomplished through the limbs performing positive and negative mechanical work on the body. Throughout a stride, the limbs collide with the ground, negative work is performed on the COM and mechanical energy is lost. To maintain a steady speed, the lost energy must be replaced through positive work...

.... , Margaria R. ( 1963 ). External work in walking . J. Appl. Physiol. 18 , 1 - 9 . Cavagna G. A. , Kaneko M. ( 1977 ). Mechanical work and efficiency in level walking and running . J. Physiol. 268 , 467 - 481 . Challis J. H. , Pain M. T. ( 2008 ). Soft tissue...

... apply to all data. * Author for correspondence ( mdonelan@sfu.ca ) 20 9 2010 © 2010. 2010 step-to-step transition gait biomechanics mechanical work metabolic cost Step-to-step transitions are an important determinant of the mechanical work and metabolic cost...

... a source of energy to the system. [For more detail, see Prilutsky( Prilutsky, 1997 ).] * Author for correspondence (e-mail: umberger@kin.umass.edu ) 9 7 2007 © The Company of Biologists Limited 2007 2007 locomotion gait biomechanics energetics mechanical work Normal...

...B. Schepens; G. J. Bastien; N. C. Heglund; P. A. Willems SUMMARY The effect of age and body size on the total mechanical work done during walking is studied in children of 3–12 years of age and in adults. The total mechanical work per stride ( W tot ) is measured as the sum of the external work, W...

... in kinetic energy and gravitational potential energy of the center of mass were nearly exactly in phase. The mass-specific external mechanical work required to travel 1 m (1.5 J kg -1 ) was similar to that for other legged animals. Thus, in spite of marked lateral bending of the trunk, the mechanics...

... between segments of the same limb, but not among the limbs or between the limbs and the centre of mass of the whole body. 16 9 1994 © The Company of Biologists Limited 1995 human locomotion mechanical work mechanical efficiency energy transfer external and internal work...

... by Company of Biologists 1990 prestretch stimulation rat gastrocnemius mechanical work In many complex movements, muscle-tendon complexes undergo stretchshortening cycles during activity (e.g. Hof et al . 1983 ; Komi, 1986 ; Gregor et al . 1988 ). During locomotion (e.g. hopping...

... a greater rate (alkalosis) or slower rate (acidosis) than that of lactate. 14 01 1986 © 1986 by Company of Biologists 1986 amphibian muscle mechanical work muscle energetics It has been suggested ( Bennett & Licht, 1973 ) that amphibians such as grass frogs, engaging...

... decline in cellular [K + ] occurred in concert with increases in extracellular [K + ], In saline-perfused gastrocnemii of Xenopus , the uptake of vascular water was proportional to the total mechanical work performed. Saline leaving the femoral vein of isotonically contracting gastrocnemius muscles had...