Hydraulic leg extension is not necessarily the main drive in large spiders

@article{Weihmann2012HydraulicLE,
  title={Hydraulic leg extension is not necessarily the main drive in large spiders},
  author={Tom Weihmann and Michael G{\"u}nther and Reinhard Blickhan},
  journal={Journal of Experimental Biology},
  year={2012},
  volume={215},
  pages={578 - 583}
}
SUMMARY Unlike most other arthropods, spiders have no extensor muscles in major leg joints. Therefore, hydraulic pressure generated in the prosoma provides leg extension. For decades, this mechanism was held responsible for the generation of the majority of the ground reaction forces, particularly in the hind legs. During propulsion, the front leg pairs must shorten whereas the hind legs have to be extended. Assuming that hind legs are essentially driven by hydraulics, their force vectors must… 
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27 Citations
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27 Citations

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Citation Type

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Biomechanics of omnidirectional strikes in flat spiders
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This work examined omnidirectional strikes in flattie spiders (Selenopidae), a group of sit-and-wait ambush predators found on open surfaces, showing a novel hunting behavior with high maneuverability that is generated with effectively controlled reconfigurations of long, laterigrade legs.
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This work presents a novel spider-inspired joint mechanism employing both pneumatics and electrically-actuated tendons capable of strong, dynamic, and rapid joint movement that can be utilized to further explore dynamics and functional biomechanics in spiders.
Measuring strain in the exoskeleton of spiders—virtues and caveats
  • R. Blickhan, T. Weihmann, F. Barth
  • Biology, Engineering
    Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology
  • 2021
TLDR
In future studies, a precise calculation and quantitative determination of strain at the sites of the lyriform organs will profit from more detailed data on the overall strain distribution, morphology, and material properties.
A Novel Bio-Inspired Fluidic Actuator for Robotic Applications
Biological research on the spider leg mechanism has inspired the development of a novel hinge joint actuator with an antagonistic fluid system. Current bio-inspired robot systems with fluidic muscles…
Rules of nature’s Formula Run: Muscle mechanics during late stance is the key to explaining maximum running speed
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A generic biomechanical model is proposed to investigate the allometry of the maximum speed of legged running and suggests considering the overall speed maximum to indicate muscle inertia being functionally significant in animal locomotion.
Leg loss decreases endurance and increases oxygen consumption during locomotion in harvestmen.
TLDR
The findings suggest that individuals have a threshold number of legs that can be lost before experiencing measurable energetic consequences, and illustrate how animals respond to morphological modifications that affect the physiology of locomotion.
Rules of nature's Formula Run: Muscle mechanics during late stance is the key to explaining maximum running speed.
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