A test of Raibert's symmetry equations in animal and human running

Based upon his work with robots, Raibert proposed that a specific class of symmetry equations may be important to animals and humans during steady-state running. In a test of this hypothesis, Raibert found good agreement with his predictions. However, his test was limited to one cat at two speeds and a human at a single speed. For the present study, we duplicated Raibert's methodology and tested his predictions for three cats, two monkeys, and a human at a variety of speeds. Our results indicate that body and limb movements in animals and humans generally are not in agreement with predictions based on the symmetry equations.