The fourth metatarsal bone is a

long bone The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities ...

in the foot. It is smaller in size than the

third metatarsal bone The third metatarsal bone is a long bone in the foot. It is the second longest metatarsal, the longest being the second metatarsal. The third metatarsal is analogous to the third metacarpal bone in the hand Like the four other metatarsal bones, ...

and is the third longest (and smallest) of the five

metatarsal bones The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

. The fourth metatarsal is analogous to the

fourth metacarpal bone The fourth metacarpal bone (metacarpal bone of the ring finger) is shorter and smaller than the third. The base is small and quadrilateral; its superior surface presents two facets, a large one medially for articulation with the hamate, and a sma ...

in the hand As the four other metatarsals bones it can be divided into three parts; base, body and head. The base is the part closest to the

ankle The ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The ...

and the head is closest to the toes. The narrowed part in the middle is referred to as the body or shaft of the bone. The bone is somewhat flatten giving it two surfaces; the plantar (towards the sole of the foot) and the dorsal side (the area facing upwards while standing). These surfaces are rough for the attachment of

ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...

s. The bone is curved longitudinally, so as to be concave below, slightly convex above. The base or posterior extremity is

wedge A wedge is a triangle, triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by conver ...

-shaped. The base presents an oblique

quadrilateral In Euclidean geometry, geometry a quadrilateral is a four-sided polygon, having four Edge (geometry), edges (sides) and four Vertex (geometry), corners (vertices). The word is derived from the Latin words ''quadri'', a variant of four, and ''l ...

surface for articulation with the

cuboid In geometry, a cuboid is a hexahedron with quadrilateral faces, meaning it is a polyhedron with six Face (geometry), faces; it has eight Vertex (geometry), vertices and twelve Edge (geometry), edges. A ''rectangular cuboid'' (sometimes also calle ...

; a smooth facet on the medial side, divided by a ridge into an anterior portion for articulation with the third metatarsal, and a posterior portion for articulation with the third cuneiform; on the lateral side a single facet, for articulation with the fifth metatarsal. The head or

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

extremity articulates with the fourth

proximal phalanx The phalanges (: phalanx ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones. Structu ...

, the first bone in the fourth toe.

Muscle attachments

The third and fourth dorsal interossei muscles attaches to the fourth metatarsal bone. The third dorsal interossei from the medial side of the bone and the fourth dorsal interossei from the lateral side. The function of the muscle is to spread the toes. The second Plantar interossei muscle originates from the medial side of the base and shaft of the fourth metatarsal. The function of the muscle is to move the fourth toe medially and move the toes together. The horizontal head of the adductor hallucis also originates from the lateral side of the

metacarpophalangeal joint The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow ...

and from the deep transverse metatarsal ligament, a narrow band which runs across and connects together the heads of all the metatarsal bones.

Additional images

File:Footx.jpg, X-ray of foot, showing phalangeal fracture File:Gray290.png, Skeleton of foot. Medial aspect. File:Gray360.png, Oblique section of left intertarsal and tarsometatarsal articulations, showing the synovial cavities. File:Foot bones - tarsus, metatarsus.jpg, Foot bones - tarsus, metatarsus File:Foot bones - metatarsus and phalanges.jpg, Foot bones - metatarsus and phalanges File:Metatarsus.jpg, Metatarsus

References

Bones of the lower limb Bones of the foot 4 {{Portal bar, Anatomy