WALKING 151 



tty the combined and balanced contraction of the muscles 

 passing from the neel to the thigh, and from the dorsum of 

 the foot to the sAin-bone (tifaa). Others passing before 

 and behind the knee-joint keep it from yielding; and so at 

 the hip-joints: and others again lying in the walls of the 

 abdomen and along the vertebral column, keep the latter 

 rigid, and erect on the pelvis; and finally the skull is kept 

 m position by muscles passing from the sternum and ver- 

 tebral column to it, in front of and behind the occipital 

 condyles. 



Locomotion includes all movements of the whole Body 

 in space, dependent on its own muscular efforts: such as 

 walking, running, leaping, and swimming. 



Walking. In walking the Body never entirely quits the 

 ground, the heel of the advanced foot touching the ground 

 in each step before the toe of the rear foot leaves it. The 

 .advanced limb supports the Body, and the foot in the rear 

 at the commencement of each step, propels it. 



Suppose a man standing with his heels together to com- 

 mence to walk, stepping out with the left foot; the whole 

 Body is at first inclined forwards; the movement taking 

 place mainly at the ankle-joints. By this means the cen- 

 tre of gravity would be thrown in front of the base formed 

 "by the feet and a fall on the face result, were not simulta- 

 neously the left foot slightly raised by bending the knee 

 and then swung forwards, the toes just clear of the ground 

 and, in good walking, the sole nearly parallel to it. When 

 the step is completed, the left knee is straightened and the 

 sole placed on the ground, the heel touching it first and, 

 the base of support being thus widened fiom before back, 

 a fall is prevented. Meanwhile the right leg is kept 

 straight, but inclines forwards above with the trunk when 

 the latter advances, and as this occurs the sole gradually 

 leaves the ground, commencing with the heel. When the 

 step of the left leg is completed the great toe of the right 

 alone is in contact with the support. With this a push is 

 given which sends the trunk on over the left leg which is 

 now kept rigid, except at the ankle-joint; and the right 

 knee being bent that limb swings forwards, its foot just 



