In spite of the cushion effect of paw pad,the rigid phalanxes of canine also suffer great impact with each stride.And those phalanxes have to transfer the impact force to the body along the skeleton and maintain the stability of the paw contacted with the ground.As is known,the German shepherd dogs have good running capability and adapt to a wide variety of terrain.In this study,the phalanxes in forepaw were investigated to reveal the mechanism of cushion,energy storage and adjustment,due to the fact that forepaw takes most percentage of the ground impact during locomotion.Firstly,the forepaws of the German shepherd dogs were dissected to observe the geometric configurations of all phalanxes and the connection characteristic of each joint.Secondly,a pressure plate system was used to investigate the regulations of the phalanxes of adjustment and adaptation,and collect the pressure data of each phalanx bearing in the process of the paw contacting with the ground.Thirdly,the computed tomography(CT)scan method was used to build the geometric models of forepaw,and the finite element analysis method was employed to analyze its biomechanical contributions to cushion.The results showed that the second to fifth phalanx were all consisted of three segments: proximal phalanx,middle phalanx,distal phalanx,and the parts that bore and transmitted the force are proximal phalanx and middle phalanx,in addition,the third and fourth phalanx had the same form,referred to the second and fifth had similar shape feature; along with the increase of velocity,German shepherd dog made adjustment of force bearing region of paw.Correspondingly,the force bearing region was shifted from the fifth phalanx and forth phalanx to third phalanx,forth phalanx.A hypothesis was proposed that the third phalanx and forth phalanx had stronger impact resistance than the other phalanxes; the finite element simulation also predicted that the third phalanx and forth phalanx could absorb and store more energy than the fifth phalanx and second phalanx under the ground impact,therefore the third phalanx and fourth phalanx may mostly contributed to resist the impact and store the energy compared with other phalanx.