scholarly journals The metabolic cost of turning right side up in the Mediterranean spur-thighed tortoise (Testudo graeca)

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Heather E. Ewart ◽  
Peter G. Tickle ◽  
William I. Sellers ◽  
Markus Lambertz ◽  
Dane A. Crossley ◽  
...  
Keyword(s):  
Video Analysis ◽  
Metabolic Cost ◽  
Physiological Process ◽  
Specific Power ◽  
Inverted Position ◽  
Testudo Graeca ◽  
Fitness Traits ◽  
Evolutionary Advantage ◽  
Cost Of Locomotion ◽  
In The Wild

AbstractArmoured, rigid bodied animals, such as Testudines, must self-right should they find themselves in an inverted position. The ability to self-right is an essential biomechanical and physiological process that influences survival and ultimately fitness. Traits that enhance righting ability may consequently offer an evolutionary advantage. However, the energetic requirements of self-righting are unknown. Using respirometry and kinematic video analysis, we examined the metabolic cost of self-righting in the terrestrial Mediterranean spur-thighed tortoise and compared this to the metabolic cost of locomotion at a moderate, easily sustainable speed. We found that self-righting is, relatively, metabolically expensive and costs around two times the mass-specific power required to walk. Rapid movements of the limbs and head facilitate successful righting however, combined with the constraints of breathing whilst upside down, contribute a significant metabolic cost. Consequently, in the wild, these animals should favour environments or behaviours where the risk of becoming inverted is reduced.

The Metabolic Cost of Locomotion; Muscle by Muscle

2011 ◽  
Vol 39 (2) ◽  
pp. 57-58 ◽  
Author(s):  
Rodger Kram ◽  
Christopher J. Arellano ◽  
Jason R. Franz
Keyword(s):  
Metabolic Cost ◽  
Cost Of Locomotion

scholarly journals The mechanics and energetics of human walking and running: a joint level perspective

2011 ◽  
Vol 9 (66) ◽  
pp. 110-118 ◽  
Author(s):  
Dominic James Farris ◽  
Gregory S. Sawicki
Keyword(s):  
Power Output ◽  
Lower Limb ◽  
Metabolic Cost ◽  
Mechanical Work ◽  
Total Power ◽  
Joint Mechanics ◽  
Metabolic Power ◽  
Cost Of Transport ◽  
Cost Of Locomotion ◽  
Shed Light

Humans walk and run at a range of speeds. While steady locomotion at a given speed requires no net mechanical work, moving faster does demand both more positive and negative mechanical work per stride. Is this increased demand met by increasing power output at all lower limb joints or just some of them? Does running rely on different joints for power output than walking? How does this contribute to the metabolic cost of locomotion? This study examined the effects of walking and running speed on lower limb joint mechanics and metabolic cost of transport in humans. Kinematic and kinetic data for 10 participants were collected for a range of walking (0.75, 1.25, 1.75, 2.0 m s −1 ) and running (2.0, 2.25, 2.75, 3.25 m s −1 ) speeds. Net metabolic power was measured by indirect calorimetry. Within each gait, there was no difference in the proportion of power contributed by each joint (hip, knee, ankle) to total power across speeds. Changing from walking to running resulted in a significant ( p = 0.02) shift in power production from the hip to the ankle which may explain the higher efficiency of running at speeds above 2.0 m s −1 and shed light on a potential mechanism behind the walk–run transition.

scholarly journals Reduced Metabolic Cost of Locomotion in Svalbard Rock Ptarmigan (Lagopus muta hyperborea) during Winter

PLoS ONE ◽  
2010 ◽  
Vol 5 (11) ◽  
pp. e15490 ◽  
Author(s):  
John Lees ◽  
Robert Nudds ◽  
Karl-Arne Stokkan ◽  
Lars Folkow ◽  
Jonathan Codd
Keyword(s):  
Metabolic Cost ◽  
Rock Ptarmigan ◽  
Cost Of Locomotion ◽  
Lagopus Muta

Improving the Assisting Efficiency of Ankle Robot through Energy Harvesting of Achilles Tendon

2020 ◽  
Author(s):  
Guowei Huang ◽  
Zhihou Wang ◽  
Biao Liu ◽  
Zikang Zhou ◽  
Xiaoming Xian ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Achilles Tendon ◽  
Substantial Reduction ◽  
Metabolic Cost ◽  
Initial Result ◽  
Specific Power ◽  
Future Research ◽  
The Novel ◽  
Physiological Structure ◽  
Novel Design

Abstract Background The construction of lightweight robots poses one of the major challenges in the field of active robots since bearing the weight of an active robot significantly increases metabolic cost. However, few studies have achieved a substantial reduction in the robot weight. The primary reason is that the weight of the actuator, which comprises the main weight of the robot, is limited by the specific power, power requirements and assisting efficiency. Methods In this paper, we propose a new method that is utilizing the energy harvesting function of the Achilles tendon to improve the assistance efficiency of ankle robots to reduce the weight of the actuator and we design a novel ankle robot to test the validity of the method. The robot works with the ankle plantar flexor at 43%-60% of the gait cycle and has no other effects on the joints or the tendon of the lower limb. Healthy subjects were recruited to test the prototype in three conditions: free walking, power-on walking, and power-off walking. Data on the robot assisting power, metabolic cost and kinematics in different conditions were collected and analyzed. Result The results showed that the ankle robot can deliver forces at the controlled assistance timing. The average assisting power of 0.0650±0.0054 W/kg per leg resulted in an 8.7±8.1% and 19.0±6.4% net reduction in metabolic cost in power-on walking compared to free-walking and power-off walking, respectively. Conclusion Compared with the results of some of the best research, our initial result supports the validity of the method. This method can help to reduce the weight of active robots and the technical innovative method to determine the assistance timing more accurately and the novel design of the ankle robot can provide a reference for future research. To the best of our knowledge, this method is the first to use the human physiological structure to optimize the design of active robots.

scholarly journals An extensive common‐garden study with domesticated and wild Atlantic salmon in the wild reveals impact on smolt production and shifts in fitness traits

2019 ◽  
Vol 12 (5) ◽  
pp. 1001-1016 ◽  
Author(s):  
Øystein Skaala ◽  
Francois Besnier ◽  
Reidar Borgstrøm ◽  
BjørnTorgeir Barlaup ◽  
Anne Grete Sørvik ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Common Garden ◽  
Fitness Traits ◽  
In The Wild ◽  
And Shifts

scholarly journals The hotspots in primate cortical brain evolution support supramodal cognitive flexibility

2018 ◽  
Author(s):  
Markus H. Sneve ◽  
Håkon Grydeland ◽  
Marcello G. P. Rosa ◽  
Tomáš Paus ◽  
Tristan Chaplin ◽  
...  
Keyword(s):  
Brain Networks ◽  
Brain Evolution ◽  
Metabolic Cost ◽  
Developmental Trajectory ◽  
Primate Species ◽  
Cognitive State ◽  
Dependent Manner ◽  
Functional Connections ◽  
Evolutionary Advantage ◽  
Series Of Experiments

AbstractPrimate cortical evolution has been characterized by massive and disproportionate expansion of a set of specific regions in the neocortex. The associated increase in neocortical neurons comes with a high metabolic cost, thus the functions served by these regions must have conferred significant evolutionary advantage. Here, across a series of experiments, we show that the evolutionary high-expanding ‘hotspots’ – as estimated from patterns of evolutionary expansion from several primate species – share functional connections with different brain networks in a context-dependent manner. This capacity of the hotspots to connect flexibly with various specialized brain networks depending on particular cognitive requirements suggests that their selective growth and sustainment in evolution has been linked to their involvement in supramodal cognition. In accordance with an evolutionary-developmental view, we find that this ability to flexibly modulate functional connections as a function of cognitive state emerges gradually through childhood, with a prolonged developmental trajectory plateauing in young adulthood.

scholarly journals A PHYSIOLOGIST'S PERSPECTIVE ON ROBOTIC EXOSKELETONS FOR HUMAN LOCOMOTION

2007 ◽  
Vol 04 (03) ◽  
pp. 507-528 ◽  
Author(s):  
DANIEL P. FERRIS ◽  
GREGORY S. SAWICKI ◽  
MONICA A. DALEY
Keyword(s):  
Science Fiction ◽  
Metabolic Cost ◽  
Human Locomotion ◽  
Metabolic Energy ◽  
Future Research ◽  
Future Studies ◽  
Technological Advances ◽  
Cost Of Locomotion ◽  
Metabolic Energy Expenditure ◽  
Insight Into

Technological advances in robotic hardware and software have enabled powered exoskeletons to move from science fiction to the real world. The objective of this article is to emphasize two main points for future research. First, the design of future devices could be improved by exploiting biomechanical principles of animal locomotion. Two goals in exoskeleton research could particularly benefit from additional physiological perspective: (i) reduction in the metabolic energy expenditure of the user while wearing the device, and (ii) minimization of the power requirements for actuating the exoskeleton. Second, a reciprocal potential exists for robotic exoskeletons to advance our understanding of human locomotor physiology. Experimental data from humans walking and running with robotic exoskeletons could provide important insight into the metabolic cost of locomotion that is impossible to gain with other methods. Given the mutual benefits of collaboration, it is imperative that engineers and physiologists work together in future studies on robotic exoskeletons for human locomotion.

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