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 bone, short, Flat bone, flat, Irregular bone, irregular and Sesamoid bone, sesamoid. Long bones, especially the femur and tibia, are subj ...

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 As the four other metatarsals bones it c ...

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

metatarsal bones The metatarsal bones, or metatarsus, are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medi ...

. 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, or 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 join ...

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 The sole is the bottom of the foot. In humans the sole of the foot is anatomically referred to as the plantar aspect. Structure The glabrous skin on the sole of the foot lacks the hair and pigmentation found elsewhere on the body, and it has ...

) and the dorsal side (the area facing upwards while standing). These surfaces are rough for the attachment of

ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

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 triangular shaped tool, and is 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 converti ...

-shaped. The base presents an

oblique Oblique may refer to: * an alternative name for the character usually called a slash (punctuation) ( / ) * Oblique angle, in geometry *Oblique triangle, in geometry *Oblique lattice, in geometry * Oblique leaf base, a characteristic shape of the b ...

quadrilateral In geometry a quadrilateral is a four-sided polygon, having four edges (sides) and four corners (vertices). The word is derived from the Latin words ''quadri'', a variant of four, and ''latus'', meaning "side". It is also called a tetragon, ...

surface for articulation with the

cuboid In geometry, a cuboid is a hexahedron, a six-faced solid. Its faces are quadrilaterals. Cuboid means "like a cube", in the sense that by adjusting the length of the edges or the angles between edges and faces a cuboid can be transformed into a cub ...

; a smooth facet on the medial side, divided by a ridge into an anterior portion for articulation with the

third metatarsal 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 As the four other metatarsals bones it c ...

, and a posterior portion for articulation with the third cuneiform; on the lateral side a single facet, for articulation with the

fifth metatarsal The fifth metatarsal bone is a long bone in the foot, and is palpable along the distal outer edges of the feet. It is the second smallest of the five metatarsal bones. The fifth metatarsal is analogous to the fifth metacarpal bone in the hand. As ...

. The head or

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

extremity articulates with the fourth

proximal phalanx The phalanges (singular: ''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. ...

, 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 The Adductor hallucis (Adductor obliquus hallucis) arises by two heads—oblique and transverse and is responsible for adducting the big toe. It has two heads, both are innervated by the lateral plantar nerve. Structure Oblique head The ''oblique ...

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 cav ...

and from the deep

transverse metatarsal ligament The transverse metatarsal ligament is a narrow band which runs across and connects together the heads of all the metatarsal bones. It is blended anteriorly with the plantar (glenoid) ligaments of the metatarsophalangeal articulations. Its plantar ...

, 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