Novel X-ray video of fruit bats mid-flight reveals a remarkably detailed look at the muscular and skeletal structure required for the mammals to take flight.

Using XROMM (X-ray Reconstruction of Moving Morphology) technology, a team of scientists led by Brown University's Nicolai Konow was able to better understand how bats manage to be the only mammal capable of sustained flight by capturing three-dimensional images of bone structure and movement patterns.

A big player in the bats' ability to get airborne, the researchers learned, is the mammals' capacity to store and recycle energy in the extra-stretchy material of their bicep and triceps tendons.

Konow and his colleagues' analysis revealed that the bats first stretch out the tendons that anchor their biceps and triceps muscles to their bone, and then compress the tendons to release energy and power their flight upward. The movement harnesses "elastic energy" just like a stretched rubber band snaps back, a force which gives the bats an extra boost.

The finding was contrary to previous beliefs that small mammals like bats have tendons too stiff and thick to be stretched at all.

Capturing video of the bats came easily for Konow.

"Bats don't like being on the ground, so we just put them on the ground and filmed them as they took off," he said, according to the BBC.

Bats' use of elastic energy may prove to be an inspiration for future bio-inspired designs for robots, which Konow said could benefit from having energy stored in the system.

"The fact that bats are able to pack such an incredible functional repertoire into such a tiny body utterly amazes me," Konow told the BBC, adding that bats don't just fly but walk, run jump and even swim.

"And that could have thrilling applications in terms of search and rescue in catastrophe zones." The videos and research were presented recently at the Society for Experimental Biology's annual meeting in Valencia, Spain.