Near the rear there are two bones, on the right and on the left, connected in the middle by a fixed joint. They serve as a basis for all the overlying bones and a carrier and engine for the bones lying below. Each of these bones is divided into four parts. The bone adjacent to the outer side is called the harkafa or ilium; the one adjacent to the front is called the pubic bone; the one that is adjacent to the back is called the ischium, and the one that is adjacent to the bottom and inside is called the “thigh box”, since it has a depression into which the convex head of the femur fits. Important organs such as the bladder, uterus, spermatic vessels in men, anus, and rectum lie on this bone.
Speaking generally about the usefulness of the leg, it should be said that it is useful in two respects. The first is stability and the ability to stand, and this is achieved by the foot, and the second is moving straight, up and down, and this is achieved with the help of the thigh and lower leg. When the foot is damaged, it is difficult to stand steadily, and it is possible to move only to the extent that movement requires excessive stability of one of the legs. When damage occurs to the thigh or lower leg muscle, it is easy to stand still and difficult to move.