Muscle power: Bats power take-off using recycled energy

July 5, 2013
A new study used cutting edge technology to image how Seba's short tailed fruitbats move through the air. Credit: Brock Fenton, U.W.O.

Bats are uniquely able to stretch and store energy in their bicep and tricep tendons during take-off and climbing flight, giving them an extra power boost. A new study on fruitbats, to be presented at the meeting of the Society for Experimental in Valencia on July 4, used cutting edge technology to image how these small mammals move through the air.

Dr Nicolai Konow (Brown University, USA), who led the research said: "Energy is stored in the triceps tendon, which is used to power elbow extension – in essence, elbow extension happens using "recycled" energy. State of knowledge, and our results, indicates that bats are unique among in stretching their tendons, as small mammal limb tendons are thought to be too thick and stiff to be stretched."

"By combining information about skeletal movement with information about muscle mechanics, we found that the biceps and triceps tendons of small fruitbats are stretched and store energy as the bat launches from the ground and flies vertically."

The researchers used a cutting edge 3D imaging technology called XROMM (X-ray Reconstruction of Moving Morphology) that allows visualizing rapid internal skeletal movement. XROMM combines 3D models of bone morphology with movement data from biplanar x-ray video to create highly accurate re-animations of the 3D bones moving in 3D space. The researchers also used a novel method called fluoromicrometry, where small radio opaque markers are implanted directly into muscle, which allows measuring length change with high precision and accuracy during contractions.

This video is not supported by your browser at this time.
This is a composite video, showing two orthogonal high-speed xray views of a Seba's short tailed fruitbat taking off from the ground and transitioning into vertical ascending flight towards a landing area (out of view). Onto the biplanar high speed videos, the researchers rotoscoped the micro CT scans of scapulum (shoulder-blade), humerus (upper arm bone) and radius (lower arm bone). In this way, they achieved a new set of raw measurements, showing how the mammalian scapulum moves a lot during flight, involving both translations and rotations. The researchers also used this XROMM model to understand how the biceps muscle tendon unit changes length. Like in humans, the biceps spans both the shoulder and elbow joints. This anatomy represents a biomechanical problem, because measuring elbow flexion and extension does not reveal the length of the whole muscle tendon unit. Therefore, the researchers needed the XROMM model to understand biceps contraction biomechanics, which helped them reveal that the biceps tendon is being stretched during a wingbeat cycle. Credit: Nicolai Konow & Rhea von Busse, the Aeromechanics and Evolutionary Morphology Laboratory at Brown University

These findings indicate that the action of muscles powering through fluids may be influenced by series elasticity, and that at least some limb tendons in small mammals can be stretched by muscular and , enabling force control of joint movement.

This research will likely have relevance for the development of autonomous micro aircrafts and potentially also amphibious search and rescue vehicles.

Explore further: High-strain tendons repair less frequently

Related Stories

High-strain tendons repair less frequently

May 25, 2010

In a discovery that seems counterintuitive, a study appearing in the May 21st Journal of Biological Chemistry has found that tendons in high-stress and strain areas, like the Achilles tendon, actually repair themselves less ...

Tendons absorb shocks muscles won't handle

September 27, 2011

Anyone who has hiked down a mountain knows the soreness that comes a day or two after means the leg muscles have endured a serious workout. While the pain is real, it's not well understood how leg muscles cope with the force ...

Frogs' amazing leaps due to springy tendons

November 16, 2011

Some species of frogs and many other animals are able to jump far beyond what appear to be their capabilities. The trained contestants in the frog-jumping competition in Calaveras County, Calif., come to mind, but even ordinary ...

BaTboT is up for imitating smart bat maneuvers

June 3, 2012

( -- Robotics researchers in Spain and the U.S. are studying bats for their design work on drones. Bat wings are highly articulated, with skeletons similar to those of human arms and hands. The researchers have built ...

Researchers build robotic bat wing (w/ video)

February 21, 2013

The strong, flapping flight of bats offers great possibilities for the design of small aircraft, among other applications. By building a robotic bat wing, Brown researchers have uncovered flight secrets of real bats: the ...

A robot that runs like a cat (w/ Video)

June 17, 2013

Thanks to its legs, whose design faithfully reproduces feline morphology, EPFL's 4-legged 'cheetah-cub robot' has the same advantages as its model: It is small, light and fast.

Recommended for you

New gene map reveals cancer's Achilles heel

November 25, 2015

Scientists have mapped out the genes that keep our cells alive, creating a long-awaited foothold for understanding how our genome works and which genes are crucial in disease like cancer.

Study suggests fish can experience 'emotional fever'

November 25, 2015

(—A small team of researchers from the U.K. and Spain has found via lab study that at least one type of fish is capable of experiencing 'emotional fever,' which suggests it may qualify as a sentient being. In their ...

How cells in the developing ear 'practice' hearing

November 25, 2015

Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular ...

How cells 'climb' to build fruit fly tracheas

November 25, 2015

Fruit fly windpipes are much more like human blood vessels than the entryway to human lungs. To create that intricate network, fly embryonic cells must sprout "fingers" and crawl into place. Now researchers at The Johns Hopkins ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jul 06, 2013
Good study and nice vid

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.