According to a new study coauthored by Richard Marsh, PhD, a biology professor in the College of Science, Northeastern University, Boston, Massachusetts, emus, ostriches, and humans have similar walking and running mechanics and the ability to use energy efficiently. This basic finding, Marsh says, may provide information for developing the next generation of prosthetic legs and ankles.
Researchers found that emus and ostriches prefer to walk and run within a narrow range of metabolically economical speeds, and that despite anatomical differences, humans follow the same pattern although humans are not as efficient when running.
The study, “Gait-Specific Energetics Contributes to Economical Walking and Running in Emus and Ostriches,” was published online December 1, 2010, in the Proceedings of the Royal Society B. Coauthors include California State Polytechnic Institute at Pomona researchers Rebecca R. Watson, Lisa Coder, and Donald F. Hoyt, PhD; Matthew Propert, one of Marsh’s former undergraduate biology students; and Jonas Rubenson, PhD, an assistant professor in the School of Sports, Science, Exercise, and Health, University of Western Australia (UWA), Perth.
Rubenson’s contributions built upon a prior study he conducted that involved gait and motion analysis of limb swing in ostriches and humans-the two are of similar mass and generate the same amount of power to swing limbs. This study, “Adaptation for Economical Bipedal Running: The Effect of Limb Structure on Three-Dimensional Joint Mechanics,” published online October 28, 2010, in the Journal of the Royal Society Interface, shows that ostriches burn 50 percent less calories when running compared to humans because the avians use tendons to store and return twice as much elastic energy, or spring to their step, a finding that Rubenson says shows better prosthetic design should focus on elastic propulsion.
“What I always tell beginning students to the lab is that if we don’t understand the normal function of the limb, we can’t really hope to optimize rehabilitation strategies and fix problems,” Marsh was quoted as saying in a [email protected] press release.
