Skip Nav Destination
1-20 of 23
Keywords: work loopClose
J Exp Biol (2020) 223 (21): jeb225839.
Published: 12 November 2020
... amplitude over frequency may instead derive from limitations of muscle physiology at high frequency. We tested this hypothesis by developing a novel in situ work loop approach to measure muscle force and power output from the whole pectoralis major of zebra finches. This method allowed for multiple...
Includes: Supplementary data
J Exp Biol (2020) 223 (1): jeb199018.
Published: 06 January 2020
... frequency. Muscle Work loop Force Running Cockroach Viscoelastic Muscle produces, dissipates, stores, returns and transmits mechanical energy to adopt diverse functions during locomotion ( Dickinson et al., 2000 ). Even the same muscle can adopt different functions in unsteady...
J Exp Biol (2019) 222 (7): jeb195578.
Published: 05 April 2019
... of the humerotriceps, we developed an in situ work loop approach to measure how activation duration and contractile cycle frequency affected muscle work and power across the full range of activation onset times. The humerotriceps produced predominantly net negative power, likely due to relatively long stimulus...
Includes: Supplementary data
J Exp Biol (2018) 221 (21): jeb190132.
Published: 05 November 2018
... served as controls or underwent 8 weeks of voluntary wheel running. Following the treatment intervention, whole soleus (SOL) or a section of the costal diaphragm (DIA) was isolated from each mouse and tested to determine the effect of 70 µmol l −1 caffeine on work loop power output. Although caffeine...
J Exp Biol (2016) 219 (2): 183–188.
Published: 01 January 2016
... in vivo . Robert Josephson incorporated lengthening contractions into a work loop analysis that shifted the focus to dynamic muscle function, varying force, length and work done both by and on muscle during a single muscle work cycle. It became apparent that muscle is both a force generator and a spring...
J Exp Biol (2015) 218 (22): 3589–3595.
Published: 01 November 2015
... (force per muscle cross-sectional area) and maximal work loop power output (normalised to muscle mass) all significantly increased with greater SVL. In contrast, fatigue resistance during repeated work loops significantly decreased with SVL and there was no effect of size on tetanus activation time. When...
J Exp Biol (2015) 218 (19): 3150–3159.
Published: 01 October 2015
... elements (CEs) within a compliant muscle–tendon unit (MTU), we used a novel work loop approach that included implanted sonomicrometry crystals along muscle fascicles. This enabled us to decouple CE and SEE length trajectories when cyclic strain patterns were applied to an isolated plantaris MTU from...
J Exp Biol (2013) 216 (14): 2587–2594.
Published: 15 July 2013
... lasting more than a week, during which the animals are largely immobile. Previous hibernation studies have demonstrated that such natural models of skeletal muscle disuse cause limited or no change in either skeletal muscle size or contractile performance. However, work loop analysis of skeletal muscle...
J Exp Biol (2012) 215 (3): 552–558.
Published: 01 February 2012
... of temperature on sustained skeletal muscle performance. The iliotibialis muscle was isolated from eight male Xenopus tropicalis individuals and subjected to in vitro isometric and work-loop studies at test temperatures of 15, 24, 30 and 32°C. Work-loop power output (average power per cycle) was maximised...
J Exp Biol (2012) 215 (2): 324–330.
Published: 15 January 2012
... 0 was set and control work loops performed as described above. The muscle was stimulated using the apparatus described above with the stimulation pulses delivered via fine silver wires soldered onto the stainless steel rods. The mechanical work output of the muscle is provided...
J Exp Biol (2008) 211 (10): 1603–1611.
Published: 15 May 2008
... and power production were measured in isolated bundles of red fibres from 0.5 L by the work loop technique. Power was maximal at 3–4 Hz and fell to less than 50% of maximum after 6 Hz. Based on the timing of activation, muscle strain, tail beat frequencies and forces in the caudal tendon while swimming, we...
J Exp Biol (2008) 211 (6): 873–882.
Published: 15 March 2008
... resting length. We subjected in vitro VIL preparations to strain cycling and stimulus phase and duration similar to that of natural crawling. The resulting work loops were figure-eight shaped, with the muscle performing work during the shortest 45–65% of the strain cycle but dissipating work during...
J Exp Biol (2008) 211 (2): 180–186.
Published: 15 January 2008
... and activation. A simulated work loop method was used to understand prior observations of sub-maximal power output in the dominant flight musculature of the hawkmoth Manduca sexta L. Here we show that mechanical work output and energy consumption ( via ATP) vary with the phase of activation, although they do so...
J Exp Biol (2007) 210 (7): 1194–1203.
Published: 01 April 2007
...Jeanine M. Donley; Robert E. Shadwick; Chugey A. Sepulveda; Douglas A. Syme The work loop technique was used to examine contractile properties of the red aerobic locomotor muscle (RM) in the ectothermic leopard shark Triakis semifasciata and endothermic shortfin mako shark Isurus oxyrinchus...
J Exp Biol (2007) 210 (5): 825–835.
Published: 01 March 2007
... months of aestivation (time to peak twitch increased by 25%, time from peak twitch to half relaxation increased by 34% and time from last stimulus to half tetanus relation increased by 20%). However, the results of the work-loop analysis clearly demonstrate that, despite changes to muscle morphology...
J Exp Biol (2006) 209 (17): 3370–3382.
Published: 01 September 2006
...-velocity data using three-dimensional regression analysis. Exp. Physiol. 79 , 235 -239. muscle work loop motor control The nervous system generates electrical signals that activate the locomotor muscles of an animal to produce movements like running, flying and swimming. Along...
J Exp Biol (2004) 207 (5): 767–776.
Published: 15 February 2004
... dragonfly flight motor lever arm basalar muscle work loop load lifting One of the most clearly established and widely known facts in locomotor physiology is that the maximum force exerted by a muscle is determined by its cross-sectional area, i.e. the number of actomyosin cross-bridges working...
J Exp Biol (2002) 205 (3): 379–389.
Published: 01 February 2002
..., MA 01730, USA (e-mail: firstname.lastname@example.org ) 16 11 2001 © The Company of Biologists Limited 2002 2002 muscle electromyography work loop neural control locomotion biomechanics insect arthropod Blaberus discoidalis cockroach. By measuring muscle length changes...
J Exp Biol (2002) 205 (2): 189–200.
Published: 15 January 2002
... were studied. Work and power were measured at 25°C using the work loop technique. Stimulus phases and durations and muscle strains (±5.5 % in ANT and ±8 % in POST locations) experienced during cruise swimming at different speeds were obtained from previous studies and used during work loop recordings...
J Exp Biol (2001) 204 (23): 4125–4139.
Published: 01 December 2001
...Robert K. Josephson; Jean G. Malamud; Darrell R. Stokes SUMMARY Mechanical power output and metabolic power input were measured from an asynchronous flight muscle, the basalar muscle of the beetle Cotinus mutabilis . Mechanical power output was determined using the work loop technique and metabolic...