THE POSTERIOR LIMB. » 221 
(1) The adductor brevis. Origin: Anterior portion of the 
symphysis pubis. Insertion: Below the pectineus. 
(m) The adductor longus. Origin: Posterior portion of the 
symphysis and inferior ramus of the ischium. Insertion: 
Posterior surface of the shaft of the femur to its distal third. 
(n) The adductor magnus. Origin: Ventral surface of the 
ischial tuberosity. Insertion: Medial surface of the distal 
end of the femur, extending to the medial condyle of the 
tibia. 
3. Muscles arising from the pelvic girdle and the femur and 
inserted on the proximal portions of the tibia and fibula (extensors 
and flexors of the leg). (Fig. 76). 
A. Extensor group (quadriceps femoris). The muscles lie 
for the most part in front of the axis of the femur. They have a 
common insertion on the tibial tuberosity through the patella and 
the patellar ligament. 
(a) The rectus femoris. Origin in two portions: 
First portion: Superior anterior spine, fused with the 
tensor fasciae latae, and ventral border of the iliac wing. 
Second portion: By a stout round tendon from the inferior 
anterior spine, immediately in front of the acetabulum. 
This part is cylindrical in shape and is almost a separate 
muscle. 
The two portions of the muscle should be divided. 
(b) The vastus lateralis. Origin: Anterior surface of the 
great trochanter and the lateral intermuscular ligament. 
The muscle should be divided. 
(c) The vastus intermedius. Origin in two portions: 
First portion: Great trochanter, below the origin of the 
vastus lateralis. 
Second portion: Anterior surface of the femur. 
(d) The vastus medialis. Origin: Medially, at the base of 
the collum femoris and adjacent portion of the shaft. 
Common insertion (a-d): Tibial tuberosity. 
B. Flexor group (hamstring muscles). With the exception of 
the sartorius, the muscles lie behind the axis of the femur, and are 
