First metatarsal
Os metatarsi I
The first metatarsal is the bone behind the big toe. It is the shortest and thickest of the five metatarsals and carries the most load when you push off.
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Free 3D model of the first metatarsal. Right foot. Drag to rotate, zoom with + and − (or Ctrl + scroll), click a bone to highlight and name it.
Key points
- The first metatarsal is the bone behind the big toe.
- It is the shortest and thickest of the five metatarsals.
- Its head rests on the two sesamoid bones.
- It carries the largest share of load at push-off.
What is the first metatarsal?
The first metatarsal is the long bone that leads to the big toe. It is the innermost of the five metatarsals and by far the strongest.
Where is the first metatarsal?
It lies on the inner side of the forefoot, between the medial cuneiform and the big toe. Its head is the firm lump at the base of the big toe.
Parts of the first metatarsal
The base has a kidney-shaped surface that meets the medial cuneiform. The shaft is short and thick. The head is large and rounded.
The underside of the head has two grooves separated by a low ridge. One sesamoid bone glides in each groove.
What does the first metatarsal articulate with?
Behind, it meets the medial cuneiform. In front, its head meets the proximal phalanx of the big toe at the first metatarsophalangeal joint. Underneath, it rests on the two sesamoids.
What attaches to the first metatarsal?
Two tendons that hold up the arch attach at its base: tibialis anterior on the inner side and fibularis longus on the underside. They pull in opposite directions and steady the bone.
What does the first metatarsal do?
Its head is the inner half of the ball of the foot. During push-off it carries about twice the load of any other metatarsal.
Common problems with the first metatarsal
A bunion forms when the first metatarsal drifts toward the midline and the big toe angles the other way. The head then sticks out on the inner side of the foot.
Stiffness and arthritis of the big toe joint, and gout, also centre on this joint. This page describes anatomy only.
Common questions
Where is the first metatarsal?
On the inner side of the forefoot, behind the big toe.
What is the first metatarsal head?
The rounded front end of the bone. It forms the big toe joint and rests on the sesamoids.
Which metatarsal is the shortest?
The first. It is also the thickest.
Is a bunion a bone?
It is the head of the first metatarsal made prominent by a change in the bone's angle, sometimes with extra bone around it.
Is this 3D model of the first metatarsal free?
Yes. The interactive 3D model on this page is free to view and use for study, with no account or download needed. Its geometry comes from the open BodyParts3D data set (CC BY-SA).
About this free 3D model of the first metatarsal
The interactive 3D model on this page is free to use in your browser, with no sign-up. It is built from scan-based anatomy data, so every bone is a separate, correctly placed shape you can turn and inspect from any side.