C: 
THE POSTERIOR LIMB. 229 
Flexor group. The muscles arise from the medial and 
lateral condyles of tibia and femur (the flexor digitorum sublimis 
from the posterior surface of the tibia). They lie behind the axis 
of the tibia, and are inserted both on the heel and on the plantar 
surface of the foot. 
(a) 
(b) 
(c) 
(d) 
The triceps surae comprises: 
(1) The gastrocnemius. Origin: in two portions: 
Caput laterale: Lateral condyles of tibia and femur and 
related femoral sesamoid. 
Caput mediale: Medial condyle of the femur and its sesa- 
moid. 
(2) The soleus: Origin: By astrong tendon from the 
head of the fibula. 
Insertion: Through the Achilles’ tendon (tendo calcaneus). 
The latter passes over the posterior end of the tuber cal- 
canei, and is attached to its ventral surface. The tendon is 
covered by that of the plantaris muscle. 
The small saphenous artery and vein lie at the posterior margin of 
the lateral head of the gastrocnemius in company with the lesser sap- 
henous nerve. 
The plantaris. Origin: Lateral condyle of the femur and 
associated sesamoid. Insertion: The tendon passes over 
the heel to the plantar surface of the foot, and divides into 
four parts for insertion on the second phalanges of the four 
developed digits. 
The two muscles should be divided. 
The popliteus. Origin: Lateral condyle of the femur: 
The tendon passes through the capsule of the knee-joint. 
The muscle contains the tibial sesamoid. It crosses the 
posterior surface of the tibia obliquely, and is inserted on the 
proximal portion of its posteromedial angle. 
The flexor digitorum longus. Origin: Lateral condyle 
of the tibia and head of the fibula, extending to the posterior 
surface of the interosseous ligament and associated portions 
of the tibia and fibula. Insertion: The tendon passes 
beneath the sustentaculum tali, reaching the plantar surface 
of the foot, where it is partly covered by the plantaris ten- 
don. It divides into four parts for insertion on the ungual 
phalanges of the four developed digits. 
