In order to test his hypothesis Biewener made different sized mammals run on a force platform where he filmed the mammals in lateral view in order to determine the mechanical advantage of the ground reaction force in relation to the moments exerted at the joints that corresponded. To determine the mechanical advantage of the extensor groups Biewener used radiographs or anatomic dissection, and adjusted for observed angular displacements at joints. Once the mechanical advantage for both of these were found the EMA of extensor muscle was calculated for the joints of the forelimb and hindlimb when the limb was in contact with the ground.
The results in Biewener’s experiment show that the peak stresses in the muscle are relatively uniform in mammals of varying body sizes. In fact the results show the EMA scales almost proportional to body mass. The results also show that there was no significant change in EMA when a species was changing gates or moving at varying speeds. These results support Biewener’s theory that limb posture would adjust when species got larger to a more upright position in order to have similar stresses act upon joints as smaller mammals