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Knowing how an ostrich can run without wasting too much energy could help engineers build better prosthetic limbs and more efficient robots, according to a researcher at The University of Western Australia.

Assistant Professor Jonas Rubenson of the Biomechanics Group in UWA's School of Sport Science, Exercise and Health compared how humans and ostriches run in a study to be published online in Interface , a journal of the Royal Society, on Wednesday 27 October.

Using computer modelling techniques and reflective markers on the limbs to capture their motion, Assistant Professor Rubenson and his team analysed the human movement in the School's state of the art Biomechanics Laboratory.  Five ‘very tame' ostriches were studied at the Gosnells property of one of the study's co-authors (Denham Heliams) where a 50m track was built.  Humans and ostriches were observed in three dimensions, permitting motion to be studied front-on, sideways, and from a bird's eye perspective.

"We chose to study ostriches because ostriches and humans are of a similar mass and are two-legged, or bipedal," Assistant Professor Rubenson said.  "Animals such as the ostrich are specialised to run both fast and remarkably economically.  By comparing ostriches to their less economical two-legged counterpart - humans - our team found the difference lies in the elasticity of their joints.  Ostriches use tendons to store and return twice as much elastic energy per step than us, reducing the work required by their muscles."

While ostriches and humans burn a similar amount of calories in walking, when it comes to running, ostriches require almost 50 per cent less.  Assistant Professor Rubenson compares their movement to that of a bouncing ball or pogo-stick: "It's all in the spring of their step!"

Assistant Professor Rubenson received his PhD from UWA, where he studied the role of mechanical energetics as a determinant of the energy cost of bipedal running.  In subsequent post-doctoral positions in the US he gained expertise in both mechanical and energetic measurements of skeletal muscle in animal models as well as experimental measurement and musculoskeletal modeling of muscle function in humans.

"The UWA lab adopts experimental and modeling approaches in both humans and animal systems, and applies this knowledge to improving human health and performance," he said.  "My current projects involve measuring human muscle strain, force and energy use during movement in both normal and gait-impaired individuals.  Future work aims at applying this information in technologies for enhancing human gait, such as improving locomotor economy and reducing muscle injuries."

Media references

Assistant Professor Jonas Rubenson (UWA School of Sport Science, Exercise and Health)  (+61 8)  6488 5533
Janine MacDonald (UWA Public Affairs)  (+61 8)  6488 5563  /  (+61 4) 32 637 716