Tag Archives: locomotion

Watch Your Step: How Vision Leads Locomotion

AUSTIN, Texas — Using new technologies to track how vision guides foot placement, researchers at The University of Texas at Austin come one step closer in determining what is going on in the brain while we walk, paving the way for better treatment for mobility impairments — strokes, aging and Parkinson’s — and technology development — prosthetics and robots. (more…)

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Researchers Use ‘Avatar’ Experiments to Get Leg Up on Locomotion

Simple mechanical descriptions of the way people and animals walk, run, jump and hop liken whole leg behavior to a spring or pogo stick.

But until now, no one has mapped the body’s complex physiology – which in locomotion includes multiple leg muscle-tendons crossing the hip, knee and ankle joints, the weight of a body, and control signals from the brain – with the rather simple physics of spring-like limb behavior. (more…)

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What singing fruit flies can tell us about quick decisions

You wouldn’t hear the mating song of the male fruit fly as you reached for the infested bananas in your kitchen. Yet, the neural activity behind the insect’s amorous call could help scientists understand how you made the quick decision to pull your hand back from the tiny swarm.

Male fruit flies base the pitch and tempo of their mating song on the movement and behavior of their desired female, Princeton University researchers have discovered. In the animal kingdom, lusty warblers such as birds typically have a mating song with a stereotyped pattern. A fruit fly’s song, however, is an unordered series of loud purrs and soft drones made by wing vibrations, the researchers reported in the journal Nature. A male adjusts his song in reaction to his specific environment, which in this case is the distance and speed of a female — the faster and farther away she’s moving, the louder he “sings.” (more…)

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Discovery of new fossils reveals key link in evolution of hind limbs

Researchers have discovered well-preserved pelves and a partial pelvic fin from Tiktaalik roseae, a 375 million-year-old transitional species between fish and the first legged animals, which reveal that the evolution of hind legs actually began as enhanced hind fins. This challenges existing theory that large, mobile hind appendages were developed only after vertebrates transitioned to land.

The scientists describe the fossils in the Proceedings of the National Academy of Sciences, online on Jan. 13. The piece marks the inaugural article for Prof. Neil Shubin, Robert R. Bensley Distinguished Service Professor of Organismal Biology and Anatomy, as a member of the National Academy of Sciences. (more…)

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Cilia use different motors for different tasks

Cilia — short, hair-like fibers — are widely present in nature. Single-celled paramecia use one set of cilia for locomotion and another set to sweep nutrients into their oral grooves. Researchers at Brown have discovered that those two cilia sets operate at different speeds when the viscosity of the environment changes. That suggests different molecular motors driving them, which could help explain how cilia have come to be used for so many different tasks in nature.

PROVIDENCE, R.I. [Brown University] — Cilia are one of nature’s great multipurpose tools. The tiny, hair-like fibers protrude from cell membranes and perform all kinds of tasks in all kinds of creatures, from helping clear debris from human lungs to enabling single-celled organisms to swim. Now, physicists from Brown University have discovered something that could help scientists understand how cilia have been adapted for so many varied tasks. (more…)

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Five-Limbed Brittle Stars Move Bilaterally, Like People

Brittle stars and people have something in common: They move in fundamentally similar ways. Though not bilaterally symmetrical like humans and many other animals, brittle stars have come up with a mechanism to choose any of its five limbs to direct its movement on the seabed. It’s as if each arm can be the creature’s front, capable of locomotion and charting direction. Results appear in the Journal of Experimental Biology.

PROVIDENCE, R.I. [Brown University] — It appears that the brittle star, the humble, five-limbed dragnet of the seabed, moves very similarly to us.

In a series of first-time experiments, Brown University evolutionary biologist Henry Astley discovered that brittle stars, despite having no brain, move in a very coordinated fashion, choosing a central arm to chart direction and then designating other limbs to propel it along. Yet when the brittle star wants to change direction, it designates a new front, meaning that it chooses a new center arm and two other limbs to move. Brittle stars have come up with a mechanism to choose any of its five limbs to be central control, each capable of determining direction or pitching in to help it move. (more…)

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Computer Modeling of Swimming Fish Could Lead To New Robots and Prosthetics

Image credit: University of Maryland

COLLEGE PARK, Md — Scientists at the University of Maryland and Tulane University have developed a computational model of a swimming fish that is the first to address the interaction of both internal and external forces on locomotion. The interdisciplinary research team simulated how the fish’s flexible body bends, depending on both the forces from the fluid moving around it as well as the muscles inside. Understanding these interactions, even in fish, will help design medical prosthetics for humans that work with the body’s natural mechanics, rather than against them. This research is published in the October 18, 2010 online early edition of the Proceedings of the National Academy of Sciences. (more…)

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