What do emus, ostriches, and humans have in common? Sim­ilar walking and run­ning mechanics and the ability to use energy effi­ciently, according to a new study coau­thored by North­eastern Uni­ver­sity researcher Richard Marsh.

The study links the muscle func­tion of ani­mals limbs with cor­re­sponding energy use, which Marsh said could spark break­throughs in the devel­op­ment of reha­bil­i­ta­tion devices for humans.

Researchers found emus and ostriches prefer to walk within a narrow range of eco­nom­ical speeds—a trend that con­tinues even when they switch to run­ning. Marsh said that despite anatom­ical dif­fer­ences, humans follow the same pat­tern. There­fore, the basic find­ings from studying the bio­me­chanics of these large birds can pro­vide cru­cial infor­ma­tion for devel­oping the next gen­er­a­tion of pros­thetic legs and ankles.

Marsh, a biology pro­fessor in the Col­lege of Sci­ence, said the goal is to “unite human and animal studies in terms of limb mechanics and energetics”—research, he said, that has been over­sim­pli­fied in the past.

He col­lab­o­rated with researchers from Cal­i­fornia State Poly­technic Insti­tute at Pomona on the paper, which was pub­lished this month in Pro­ceed­ings of the Royal Society B, a bio­log­ical sci­ences research journal. The report stems from a larger research project funded by the National Sci­ence Foun­da­tion. Matthew Propert, one of Marsh’s former under­grad­uate biology stu­dents, also con­tributed to the findings.

Marsh said the research could lead to other sig­nif­i­cant appli­ca­tions across a variety of dis­ci­plines, including arche­ology, for example. Under­standing muscle mechanics and energy use of emus, ostriches, and other large birds, Marsh said, can even shed light on how extinct ani­mals like dinosaurs once moved.

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 said.

View selected pub­li­ca­tions of Richard Marsh in IRis, Northeastern’s dig­ital archive.