First detailed analysis of quails' gait sheds light on dinosaur's locomotion

A team of motion scientists has analyzed the gait of birds to know how horizontally forward-facing posture affects the movement of their legs and on their stability when they walk.

The researchers at the Friedrich Schiller University in Jena (Germany) had quails walking through a high speed X-ray installation at varying speeds and while the installation monitored the movements of the animals meticulously, the scientists were able to measure the power at work in their legs.

From this data, the Jena research team could develop a computer model of the whole motion sequence, which served to simulate and analyze the stability and the energy balance in connection to different gaits.

Researcher Reinhard Blickhan said that the birds use the so-called "grounded running" style when they move quickly, in which at least one leg is always touching the ground, and even when running quickly, short periods of flight phases occur only very rarely between the individual steps.

Blickhan added that but this is extremely energy consuming for the animals because the body's center of gravity lies distinctly in front of their legs due to the horizontal posture and so the animals have to constantly balance out their own bodies in order to prevent falling forwards.

Unlike the legs of humans which gather energy like two coil springs and use it directly to move forwards, the bird's legs work in addition like dampers or shock absorbers and in order to prevent falling forwards or to permanently accelerate their movement, the birds practically have to brake all the time, which hapens while the bird leg is working like a spring damper.

After getting the results, researchers also want to test other birds' gait and analyze dinosaurs' locomotion with the help of the same computer model. Emanuel Andrada added that it is not clear yet how two-legged species like Allosaurus or Tyrannosaurus Rex really moved forward, but it is assumed by now that they also ran with their upper bodies thrust forwards horizontally due to biomechanical advantages.