THE POSTERIOR LIMB. 219 
2. Muscles arising from the pelvic girdle and sacrum and in- 
serted on the femur, for the most part at its proximal extremity. 
The muscles of this group enclose the proximal portion of the 
femur on its lateral, posterior, and medial sides. They are partly 
covered by the flexors of Group 3, namely, the biceps, sartorius, and 
gracilis (pp. 222, 223), which must be divided. To begin the 
dissection, see directions for removing the biceps (p. 223). The 
position of the sciatic vein (p. 225) should be noted. 
Dissection on the lateral surface posteriorly. 
(a) 
(b) 
(c) 
(d) 
The glutaeus maximus. Origin in two fleshy portions, 
joined by an aponeurosis: 
First portion: Fascia covering the sacrum in its entire length. 
This portion is triangular in shape, and is covered posteriorly 
by the first head of the biceps. 
Second portion: Anteroventral border of the iliac wing, 
fused with the tensor fasciae latae and the first head of the 
rectus femoris; also from the dorsal border and lumbar fascia 
through the aponeurosis mentioned above. 
Insertion: Third trochanter. The axis of the first portion 
is transverse, that of the second horizontal. 
Both portions of the muscle should be divided. The sciatic nerve 
and artery are then exposed. 
The glutaeus medius. Anterior border of the wing of the 
ilium and the iliac crest and fascia of the first two sacral 
vertebrae. Insertion: Greater trochanter. Some of the 
fibres pass around the medial surface of the tip of the greater 
trochanter and are inserted in the lateral wall of the tro- 
chanteric fossa. 
The muscle should be divided. 
The glutaeus minimus. Origin: Entire lateral surface 
of the body and wing of the ilium. Insertion: Greater 
trochanter. 
Remove the entire muscle. The piriformis is in contact with its 
dorsal margin posteriorly. 
The tensor fasciae latae. Origin: Anterior portion of the 
ventral border of the wing of the illum. Insertion: Broad 
