220 A MANUAL OF ANATOMY 



IV. THE BONES OF THE LOWER LIMB. 



The lower limb is arranged in four divisions, namely, hip, or 

 pelvic girdle, thigh, leg, and foot. The pelvic girdle consists of 

 the OS innominatum ; the thigh comprises the femur, with which 

 is associated the patella ; the leg is composed of the tibia and 

 fibula ; and the foot is subdivided into a tarsus, consisting of seven 

 bones, a metatarsus, comprising five bones, and phalanges, which 

 are fourteen in number. 



The Os Innominatum. 



The OS innominatum (os coxae) forms the lateral, and one half of 

 the anterior, wall of the pelvis. It is much twisted, quadrilateral, 

 and constricted about the centre. The external surface is charac- 

 terized by the acetabulum, and below and internal to this is the 

 obturator foramen. In early life the bone is composed of three 

 parts — ilium, ischium, and os pubis — which unite in the acetabulum, 

 and in the adult it is described under these three divisions. 



The ilium is the expanded portion above the acetabulum, of 

 which it forms rather less than the upper two-fifths. It presents 

 three borders and two surfaces. 



The superior border or crest is thick over its anterior and 

 posterior thirds, but thin over the middle third. It presents 

 two curves — anterior with the concavity directed inwards, and 

 posterior with the concavity outwards. Anteriorly it terminates 

 in the anterior superior spine, which gives attachment to Poupart's 

 ligament and a portion of the sartorius. Posteriorly it ends 

 in the posterior superior spine, which gives attachment to the 

 oblique sacro-iliac ligament. The crest has two lips and an inter- 

 vening space. The outer lip presents a tubercular prominence 

 about 3 inches from the anterior superior spine. Over its whole 

 extent this lip gives attachment to the iliac fascia lata ; for i|- inches 

 in front, to the tensor fasciae femoris ; over its anterior half, to the 

 obliquus externus abdominis ; and a little behind this, to the latis- 

 simus dorsi. The intervening space over its anterior two-thirds 

 gives origin to the obliquus internus abdominis, and over its pos- 

 terior fifth, to the erector spinse. The inner lip over its anterior two- 

 thirds gives origin to the transversalis abdominis, and for about 

 2 inches posteriorly, to the ilio-lumbar ligament and quadratus 

 lumborum. Immediately within the inner lip, over its anterior two- 

 thirds, the fascia transversalis and fascia iliaca take attachment. 



The anterior border extends from the anterior superior spine to 

 the ilio-pectineal eminence. Superiorly it presents the anterior inter- 

 spinous notch, the upper part of which gives partial origin to the 

 sartorius. Below this notch is the anterior inferior spine, which 

 gives origin anteriorly to the straight head of the rectus femoris, 

 and inferiorly, to the ilio-femoral ligament. Internal to this spine 



