Now all parts which are capable of motion are connected with sinews and perhaps those concerned with action in a positive way are especially so thus we find sinews in the elbow, the legs, the hands, and the feet; the other sinews are for the purpose of fastening together all those bones which require fastening; for perhaps some, eg the spine, have little or no function except that of bending, for the substance which connects the vertebrae is a serum or mucous fluid; others are bound together by sinews thus we find sinews in the joints of the limbs.