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Keywords: Efficiency
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Journal Articles
J Exp Biol (2022) 225 (22): jeb244599.
Published: 30 November 2022
...–18:00 h) swimming to examine how self-selected movement strategies are used to modulate energetic efficiency and effort. Overall, self-selected swimming speeds (individual means ranging from 1.0 to 1.96 m s −1 ) tended to minimize cost of transport, and were on the lower range of animal-preferred...
Includes: Supplementary data
Journal Articles
J Exp Biol (2022) 225 (22): jeb244967.
Published: 24 November 2022
... that the forked tail produces thrust via acceleration reaction forces like the truncate tail during cruising but at increased energetic costs. This reduced efficiency corresponds to differences in the performance of the two tail geometries and body kinematics to maintain similar overall thrust outputs. Our...
Includes: Supplementary data
Journal Articles
J Exp Biol (2021) 224 (13): jeb237586.
Published: 9 July 2021
...William T. Gough; Hayden J. Smith; Matthew S. Savoca; Max F. Czapanskiy; Frank E. Fish; Jean Potvin; K. C. Bierlich; David E. Cade; Jacopo Di Clemente; John Kennedy; Paolo Segre; Andrew Stanworth; Caroline Weir; Jeremy A. Goldbogen ABSTRACT High efficiency lunate-tail swimming with high-aspect...
Includes: Supplementary data
Journal Articles
J Exp Biol (2018) 221 (1): jeb168575.
Published: 11 January 2018
...Brad J. Gemmell; Sean P. Colin; John H. Costello ABSTRACT Recently, it has been shown that some medusae are capable of swimming very efficiently, i.e. with a low cost of transport, and that this is in part due to passive energy recapture (PER) which occurs during bell relaxation. We compared...
Includes: Supplementary data
Journal Articles
J Exp Biol (2017) 220 (8): 1509–1515.
Published: 15 April 2017
... associated with a decrease in the proportion of attached cross-bridges. ATPase activity Force depression Cross-bridge cycling Stiffness Efficiency Residual force enhancement Concentric muscle contraction Eccentric muscle contraction Isometric muscle contraction References Abbott...
Journal Articles
J Exp Biol (2016) 219 (22): 3626–3634.
Published: 15 November 2016
... efficiency, at least at slow speeds and high loads. The mass-specific total work per unit distance W tot (J kg −1  m −1 ) is the sum of the external and internal work. Both W ext and W int are independent of load at speeds up to 1.1 m s −1 ; therefore, W tot is also independent...
Journal Articles
J Exp Biol (2015) 218 (20): 3276–3283.
Published: 1 October 2015
...Giovanni A. Cavagna; Mario A. Legramandi ABSTRACT A long-lasting challenge in comparative physiology is to understand why the efficiency of the mechanical work done to maintain locomotion increases with body mass. It has been suggested that this is due to a more elastic step in larger animals. Here...
Journal Articles
J Exp Biol (2014) 217 (17): 3159–3168.
Published: 1 September 2014
.... Appl. Physiol.   107 , 739 - 742 . Cavagna   G. A. , Kaneko   M. ( 1977 ). Mechanical work and efficiency in level walking and running . J. Physiol.   268 , 467 - 481 . Cavagna   G. A. , Saibene   F. P. , Margaria   R. ( 1964 ). Mechanical work in running . J. Appl...
Includes: Supplementary data
Journal Articles
J Exp Biol (2014) 217 (9): 1588–1600.
Published: 1 May 2014
... and funnel aperture in a theoretical model of jet propulsion scaled from the smallest (1 mm mantle length) to the largest (3 m) squid. Aperture reduction during mantle contraction increases propulsive efficiency at all squid sizes, although 1 mm squid still suffer from low efficiency (20%) because...
Journal Articles
J Exp Biol (2013) 216 (5): 909–914.
Published: 1 March 2013
... for prolonged periods at a range of speeds without compromising energetic efficiency. The fascicles of both muscles exhibited rather ‘isometric’ behaviour during the early to mid stance phase of walking, which appears to be independent of walking speed or movement efficiency. However, several functional...
Journal Articles
J Exp Biol (2011) 214 (16): 2649–2653.
Published: 15 August 2011
...Frank E. Nelson; Justus D. Ortega; Sharon A. Jubrias; Kevin E. Conley; Martin J. Kushmerick Summary Can human muscle be highly efficient in vivo ? Animal muscles typically show contraction-coupling efficiencies <50% in vitro but a recent study reports that the human first dorsal interosseous...
Journal Articles
J Exp Biol (2010) 213 (16): 2788–2796.
Published: 15 August 2010
...Charlotte R. Morris; Frank E. Nelson; Graham N. Askew SUMMARY Little is known about how in vivo muscle efficiency, that is the ratio of mechanical and metabolic power, is affected by changes in locomotory tasks. One of the main problems with determining in vivo muscle efficiency is the large number...
Journal Articles
J Exp Biol (2010) 213 (7): 1195–1206.
Published: 1 April 2010
...Graham N. Askew; Richard T. Tregear; Charles P. Ellington SUMMARY For all types of locomotion, the overall efficiency with which chemical energy is converted into mechanical work increases with increasing body size. In order to gain insight into the determinants of the scaling of overall efficiency...
Journal Articles
J Exp Biol (2010) 213 (5): 707–714.
Published: 1 March 2010
...G. A. Lichtwark; C. J. Barclay SUMMARY Muscle power output and efficiency during cyclical contractions are influenced by the timing and duration of stimulation of the muscle and the interaction of the muscle with its mechanical environment. It has been suggested that tendon compliance may reduce...
Journal Articles
J Exp Biol (2010) 213 (3): 487–492.
Published: 1 February 2010
...: these corresponded to decreases in the efficiency and changes in coordination. Increases in power were achieved that were not matched by equivalent increases in EMG intensity, but did occur with changes in coordination. It is proposed that the power output from the limb is limited by the coordination pattern...
Journal Articles
J Exp Biol (2009) 212 (7): 977–985.
Published: 1 April 2009
... consistent with slower, more fatigue-resistant muscles. We hypothesized that these changes may accompany enhanced efficiency of contraction, perhaps in support of the enhanced capacity for endurance running. To assess efficiency, we measured work and associated oxygen consumption from isolated soleus...
Journal Articles
J Exp Biol (2009) 212 (1): 21–31.
Published: 1 January 2009
... kg –1 at 0.8 L * and–0.70±0.12 W kg –1 at 1.4 L * ). For every 1 J of exoskeleton positive mechanical work subjects saved 0.72 J of metabolic energy (`apparent efficiency'=1.39) at 0.8 L * and 2.6 J of metabolic energy (`apparent efficiency'=0.38) at 1.4 L * . Declining ankle muscle–tendon `apparent...
Includes: Multimedia, Supplementary data
Journal Articles
J Exp Biol (2009) 212 (1): 32–41.
Published: 1 January 2009
... <0.0008). The `apparent efficiency' of ankle muscle–tendon mechanical work decreased from 0.53 on level ground to 0.38 on 15% grade. This suggests a decreased contribution from previously stored Achilles' tendon elastic energy and an increased contribution from actively shortening ankle plantar flexor...
Includes: Multimedia, Supplementary data
Journal Articles
J Exp Biol (2008) 211 (9): 1402–1413.
Published: 1 May 2008
...) during unpowered walking. Decreases in total joint positive mechanical power due to powered ankle assistance (∼22%) were not proportional to reductions in net metabolic power (∼10%). The `apparent efficiency' of the ankle joint muscle–tendon system during human walking (∼0.61) was much greater than...
Includes: Multimedia, Supplementary data
Journal Articles
J Exp Biol (2008) 211 (2): 234–238.
Published: 15 January 2008
...Z. Jane Wang SUMMARY To seek the simplest efficient flapping wing motions and understand their relation to steady flight, a two-stroke model in the quasi-steady limit was analyzed. It was found that a family of two-stroke flapping motions have aerodynamic efficiency close to, but slightly lower...