|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
|side of the first cuneiform. Occasionally it sends a slip to the base of the second metatarsal bone. The tendon changes its direction at two points: first, behind the lateral malleolus; secondly, on the cuboid bone; in both of these situations the tendon is thickened, and, in the latter, a sesamoid fibrocartilage (sometimes a bone), is usually developed in its substance.|
FIG. 440 Cross-section through middle of leg. (Eycleshymer and Schoemaker.) (See enlarged image)
| The Peronæus brevis lies under cover of the Peronæus longus, and is a shorter and smaller muscle. It arises from the lower two-thirds of the lateral surface of the body of the fibula; medial to the Peronæus longus; and from the intermuscular septa separating it from the adjacent muscles on the front and back of the leg. The fibers pass vertically downward, and end in a tendon which runs behind the lateral malleolus along with but in front of that of the preceding muscle, the two tendons being enclosed in the same compartment, and lubricated by a common mucous sheath. It then runs forward on the lateral side of the calcaneus, above the trochlear process and the tendon of the Peronæus longus, and is inserted into the tuberosity at the base of the fifth metatarsal bone, on its lateral side.|
| On the lateral surface of the calcaneus the tendons of the Peronæi longus and brevis occupy separate osseoaponeurotic canals formed by the calcaneus and the perineal retinacula; each tendon is enveloped by a forward prolongation of the common mucous sheath.|
Variations.Fusion of the two peronæi is rare. A slip from the Peronæus longus to the base of the third, fourth or fifth metatarsal bone, or to the Adductor hallucis is occasionally seen.
| Peronæus accessorius, origin from the fibula between the longus and brevis, joins the tendon of the longus in the sole of the foot.|
| Peronæus quinti digiti, rare, origin lower fourth of the fibula under the brevis, insertion into the Extensor aponeurosis of the little toe. More common as a slip of the tendon of the Peronæus brevis.|
| Peronæus quartus, 13 per cent. (Gruber), origin back of fibula between the brevis and the Flexor hallucis, insertion into the peroneal spine of the calcaneum, (peroneocalcaneus externum), or less frequently into the tuberosity of the cuboid (peroneocuboideus).|
Nerves.The Peronæi longus and brevis are supplied by the fourth and fifth lumbar and first sacral nerves through the superficial peroneal nerve.