MUSCLES OF THE PELVIC LIMBS. 209 
medial surface of the distal end of the tibia. This groove is 
converted into a canal by a transverse ligament. Beyond the 
canal the tendon turns onto the plantar surface of the foot and 
passes through a groove on the ventral surface of the scaphoid 
bone. It then divides. 
Insertion into the outer tuberosity on the surface of the 
scaphoid, and onto the proximal end of the ventral surface of 
the medial cuneiform. 
Relations.—Outer and medial surface with the flexor longus 
digitorum (z). Lateral surface with the flexor longus hallucis (7). 
Action. —Extensor of the foot. 
B. MUSCLES ON THE DORSAL AND LATERAL SURFACES 
OF THE LOWER LEG.—M. peroneus longus (Fig. 90, g).— 
A slender, fusiform muscle lying superficially on the lateral side 
of the leg, dorsad of the soleus. 
Origin by tendon-fibres from the lateral surface of the head 
of the fibula and from the proximal half of the lateral surface 
of its shaft. 
At the junction of the middle and distal thirds of the lower 
leg the muscle ends in a slender tendon which passes through 
the groove on the lateral surface of the lateral malleolus. This 
groove is converted into a canal by a transverse ligament. 
The tendon passes through the groove on the peroneal tubercle 
of the calcaneus, then turns onto the sole of the foot and passes 
through the peroneal groove on the cuboid bone. It then turns 
mediad and passes through the groove between the ventral 
processes of the lateral cuneiform and the metatarsal until it 
reaches the first metatarsal. The entire groove is converted 
into a canal by the overlying ligaments. 
Insertion into (1) the base of the fifth metatarsal, and (2) 
the outer side of the base of the first metatarsal, and (3) by 
slender branches into the bases of the other metatarsals. 
Relations. —Outer (lateral) surface with the superficial fascia 
and the tendon of the biceps femoris. Inner surface with the 
peroneus tertius (7) and peroneus brevis (s), and with the 
extensor longus digitorum (f). At the proximal end the 
dorsal border touches the tibialis anterior (7). 
Action. —Flexor of the foot. 
