What is the metatarsus?

What it is

• The metatarsus consists of five bones which are numbered from the medial side ( ossa metatarsalia I.-V.); each presents for examination a body and two extremities. Common Characteristics of the Metatarsal Bones. —The body is prismoid in form, tapers gradually from the tarsal to the phalangeal extremity, and is curved longitudinally, so as to be concave below, slightly convex above.
• The base or posterior extremity is wedge-shaped, articulating proximally with the tarsal bones, and by its sides with the contiguous metatarsal bones: its dorsal and plantar surfaces are rough for the attachment of ligaments. The head or anterior extremity presents a convex articular surface, oblong from above downward, and extending farther backward below than above. Its sides are flattened, and on each is a depression, surmounted by a tubercle, for ligamentous attachment.
• Its plantar surface is grooved antero-posteriorly for the passage of the Flexor tendons, and marked on either side by an articular eminence continuous with the terminal articular surface. Characteristics of the Individual Metatarsal Bones. — The First Metatarsal Bone ( os metatarsale I; metatarsal bone of the great toe ) . —The first metatarsal bone is remarkable for its great thickness, and is the shortest of the metatarsal bones. The body is strong, and of well-marked prismoid form.
• The base presents, as a rule, no articular facets on its sides, but occasionally on the lateral side there is an oval facet, by which it articulates with the second metatarsal. Its proximal articular surface is of large size and kidney-shaped; its circumference is grooved, for the tarsometatarsal ligaments, and medially gives insertion to part of the tendon of the Tibialis anterior; its plantar angle presents a rough oval prominence for the insertion of the tendon of the Peronæus longus.
• The head is large; on its plantar surface are two grooved facets, on which glide sesamoid bones; the facets are separated by a smooth elevation.