| Fourth metatarsal bone | |
|---|---|
 The fourth metatarsal. (Left.) | |
 Bones of the right foot. Dorsal surface. Fourth metatarsal bone is the yellow bone second from the right | |
| Details | |
| Identifiers | |
| Latin | os metatarsale IV |
| FMA | 24505 |
| Anatomical terms of bone | |
Thefourth metatarsal bone is along bone in the foot. It is smaller in size than thethird metatarsal bone and is the third longest (and smallest) of the fivemetatarsal bones. The fourth metatarsal is analogous to thefourth metacarpal bone in the hand[1]
As the four other metatarsals bones it can be divided into three parts; base, body and head.The base is the part closest to theankle 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 thesole of the foot) and the dorsal side (the area facing upwards while standing).[1] These surfaces are rough for the attachment ofligaments. The bone is curved longitudinally, so as to be concave below, slightly convex above.
The base orposterior extremity iswedge-shaped.[1] The base presents anobliquequadrilateral surface for articulation with thecuboid; a smooth facet on the medial side, divided by a ridge into an anterior portion for articulation with thethird metatarsal, and a posterior portion for articulation with thethird cuneiform; on the lateral side a single facet, for articulation with thefifth metatarsal.
The head oranterior extremity articulates with the fourthproximal phalanx, the first bone in the fourth toe.
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The third and fourthdorsal 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.[2]
The secondPlantar 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.[2]
The horizontal head of theadductor hallucis also originates from the lateral side of themetacarpophalangeal joint and from the deeptransverse metatarsal ligament,[2] a narrow band which runs across and connects together the heads of all the metatarsal bones.
| Muscle | Direction | Attachment[3] |
|---|---|---|
| Dorsal interossei III | Origin | Medial side of the shaft |
| Dorsal interossei IV | Origin | Lateral side of the shaft |
| Plantar interossei II | Origin | Medial side of the base and shaft |
| Horizontal head ofadductor hallucis | Origin | Deeptransverse metatarsal ligament and themetacarpophalangeal joint |
This article incorporates text in thepublic domain frompage 274 of the 20th edition ofGray's Anatomy(1918)
