The first metatarsal bone is the

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in the

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just behind the

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toe. The first metatarsal bone is the shortest of the metatarsal bones 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) and the dorsal side (the area facing upwards while standing). The base presents, as a rule, no articular facets (joint surfaces) on its sides, but occasionally on the

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side there is an oval facet, by which it articulates with the second metatarsal. 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 band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

of the fibularis longus. 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 and to a small extent with the intermediate cuneiform bone.Platzer 2004, p. 218 Its proximal articular surface is large and

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-shaped; its circumference is grooved, for the tarsometatarsal ligaments, and medially gives insertion to part of the tendon of the tibialis anterior. 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 Greek word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be presen ...

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

Muscle attachments

Three muscles attach to the first metatarsal bone: the tibialis anterior, fibularis longus 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 Greek word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be presen ...

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 of the first metatarsal.

References

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