四足獣の歩行運動の筋電図学的関節機構学的研究 : III. 駈歩

Dogs were used to record the electromyographic (EMG) activity of fifty skeletal muscles and 16-mm motion pictures in the treadmill galloping and a cyclogram in a level-ground galloping. Based on the results obtained, discussion was made on the movement of the limbs in walk, trot, and gallop. Gallop is an asymmetrical gait. A trailing limb and a leading one were proved to have essentially the same movement, though the movement of the axial skeleton produced some differences between them. Each limb had essentially the same movement throughout the gaits: walk, trot, and gallop. Of course, each gait seemed different at a glance and had actually different EMG activity patterns and change of joint angles. These differences were, however, decorated by the speed of locomotion and the movement of the axial skeleton of each gait. Just before landing, the hind limb which landed on the ground nearest to the vertical line drawn from the center of gravity of the body might make the structure as a weight-bearing bracer which also operated as a lever. The fore limb which landed on the ground most apart from this vertical line might do that after landing. The fore limb might play a more important role as a balancer than a propeller.