The first metatarsal bone is the

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

in the

foot The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...

just behind the

big Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * ''Big!'', a Discovery Channel television show * ''Richard Hammond's Big'', a television show present ...

toe Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ''plan ...

. The first metatarsal bone is the shortest of the

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 ...

and by far the thickest and strongest of them. Like the four other metatarsals, it can be divided into three parts: base, body and head. The base is the part closest to the ankle and the head is closest to the big toe. The narrowed part in the middle is referred to as the body of the bone. The bone is somewhat flattened, giving it two sides: 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). The base presents, as a rule, no

articular facets A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...

(joint surfaces) on its sides, but occasionally on the

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

side there is an oval facet, by which it articulates with the

second metatarsal The second metatarsal bone is a long bone in the foot. It is the longest of the metatarsal bones, being prolonged backward and held firmly into the recess formed by the three cuneiform bones. The second metatarsal forms joints with the second prox ...

. On the lateral part of the plantar surface there is a rough oval prominence, or tuberosity, for the insertion of the

tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

of the

fibularis longus In human anatomy, the fibularis longus (also known as peroneus longus) is a superficial muscle in the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body ( eversion) and to extend the foot downwa ...

. The first metatarsal articulates (forms

joints A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

) with the

medial cuneiform There are three cuneiform ("wedge-shaped") bones in the human foot: * the first or medial cuneiform * the second or intermediate cuneiform, also known as the middle cuneiform * the third or lateral cuneiform They are located between the navicu ...

and to a small extent with the

intermediate cuneiform bone There are three cuneiform ("wedge-shaped") bones in the human foot: * the first or medial cuneiform * the second or intermediate cuneiform, also known as the middle cuneiform * the third or lateral cuneiform They are located between the navicu ...

.Platzer 2004, p. 218 Its proximal articular surface is large and

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood ...

-shaped; its circumference is grooved, for the tarsometatarsal ligaments, and medially gives insertion to part of the tendon of the

tibialis anterior The tibialis anterior muscle is a muscle in humans that originates along the upper two-thirds of the lateral (outside) surface of the tibia and inserts into the medial cuneiform and first metatarsal bones of the foot. It acts to dorsiflex and inve ...

. The body of the bone is strong, and of well-marked prismoid form. The head is large; on its plantar surface are two grooved facets on which the

sesamoid bone In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Arabic word for ' sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be pres ...

s glide; the facets are separated by a smooth elevation.

Muscle attachments

Three muscles attach to the first metatarsal bone: the

and first dorsal interosseus. The tibialis anterior inserts at the basis of the bone, while the fibularis longus inserts at the tuberosity. The lateral part of the first dorsal interosseus muscle originates from the medial side of the bone. Its function is to spread the toes.

Additional images

File:Sesamoidbone.png,

Sesamoid bone In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Arabic word for ' sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be pres ...

s at the distal end of the first metatarsal. File:Slide2BER.JPG, First metatarsal bone. Deep dissection. File:Metatarsal pseudo-epiphysis.jpg, It is common in children to have a

pseudo-epiphysis The epiphysis () is the rounded end of a long bone, at its joint with adjacent bone(s). Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate). At the joi ...

of the first metatarsal.

References

Bones of the lower limb Bones of the foot 1 {{Portal bar, Anatomy