Metatarsal bones

At a glance

English

Metatarsal bones

Latin (TA2)

Ossa metatarsi

System

Bone

Region

Foot

In order

From the first metatarsal bone to the fifth metatarsal bone

About the metatarsal bones

The forefoot is carried on five long bones, the metatarsals, numbered one to five from the great toe on the inner side to the little toe on the outer side. They match the metacarpals of the hand in layout, lying between the cuneiforms and cuboid behind and the proximal phalanges of the toes in front. The heads of the metatarsals form the ball of the foot and, together with the heel, take the weight of the body when standing.

All five share a similar design: a wedge-shaped base at the back, a long slim shaft, and a rounded head at the front. The shafts are arched along their length, convex on the dorsum and hollow beneath, and taper towards the toes. Each base meets the tarsus at a tarsometatarsal joint and, apart from the first, touches its neighbours at intermetatarsal joints; the bases are rough above and below for strong ligaments. The head bears a convex articular surface that extends further onto the sole, where a groove carries the long flexor tendons and, under the first, two sesamoid bones lie in the tendons of flexor hallucis brevis. The interosseous muscles occupy the gaps between the shafts.

The bases articulate in a set pattern. The first meets the medial cuneiform; the second is recessed between all three cuneiforms, which holds it firmly; the third meets the lateral cuneiform; the fourth meets the cuboid as well as the lateral cuneiform; and the fifth meets the cuboid. In length the second is usually the longest and the first the shortest, although the first is by far the thickest and carries the largest share of push-off load. Unlike the other four, the first has its growth plate at the base rather than at the head.

Metatarsals are frequently injured. Stress fractures, sometimes called march fractures after their link with recruits on long marches, most often affect the necks of the second and third, which are held rigidly while walking. A twisting injury of the outer foot can avulse the tuberosity at the base of the fifth, and a fracture just beyond it, the Jones fracture, heals poorly. Rigid footwear with metatarsal guards is used to protect the forefoot at work.