Third metatarsal bone
| Third metatarsal bone | |
|---|---|
 The third metatarsal. (Left.) | |
 Bones of the right foot. Dorsal surface. Third metatarsal bone is the yellow bone third from the left | |
| Details | |
| Identifiers | |
| Latin | os metatarsale III |
| FMA | 24504 |
| Anatomical terms of bone | |
Thethird metatarsal boneis along bonein the foot. It is the second longestmetatarsal,the longest being thesecond metatarsal.The third metatarsal is analogous to thethird metacarpal bonein the hand[1]
Like the four other metatarsal bones, it can be divided into three part: base, body and head. The base is the part closest to the ankle and the head is closest to the toes. The narrowed part in the middle is referred to as the body of the bone. The bone is somewhat flattened, 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, and slightly convex above.
The base orposteriorextremity iswedge-shaped.[1] The third metatarsal bone articulates proximally, by means of a triangular smooth surface, with thethird cuneiform;medially, by two facets, with thesecond metatarsal;and laterally, by a single facet, with thefourth metatarsal.This last facet is situated at the dorsal angle of the base.
The head oranteriorextremity articulates with the thirdproximal phalanx.
Muscle attachments
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The second and thirddorsal interossei musclesattaches to the third metatarsal bone. The second dorsal interossei from the medial side of the bone and the third dorsal interossei from the lateral side. The function of the muscle is to spread the toes.[2]
The firstPlantar interossei muscleoriginates from the medial side of the base and shaft of the third metatarsal. The function of the muscle is to move the third toe medially and move the toes together.[2]
The horizontal head of theadductor hallucisalso originates from the lateral side of the metacarpophalangeal 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 II | Origin | Medial side of the shaft |
| Dorsal interossei III | Origin | Lateral side of the shaft |
| Plantar interossei I | Origin | Medial side of the base and shaft |
| Horizontal head ofadductor hallucis | Origin | Deeptransverse metatarsal ligamentand themetacarpophalangeal joint |
Additional images
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X-ray of foot, showing phalangeal fracture -
Skeleton of foot. Medial aspect. -
Oblique section of left intertarsal and tarsometatarsal articulations, showing the synovial cavities. -
Foot bones - tarsus, metatarsus -
Foot bones - metatarsus and phalanges -
Metatarsus
References
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This article incorporates text in thepublic domainfrompage 274of the 20th edition ofGray's Anatomy(1918)
- ^abcBojsen-Møller, Finn; Simonsen, Erik B.; Tranum-Jensen, Jørgen (2001).Bevægeapparatets anatomi[Anatomy of the Locomotive Apparatus] (in Danish) (12th ed.). p. 246.ISBN978-87-628-0307-7.
- ^abcBojsen-Møller, Finn; Simonsen, Erik B.; Tranum-Jensen, Jørgen (2001).Bevægeapparatets anatomi[Anatomy of the Locomotive Apparatus] (in Danish) (12th ed.). pp. 300–301.ISBN978-87-628-0307-7.
- ^Bojsen-Møller, Finn; Simonsen, Erik B.; Tranum-Jensen, Jørgen (2001).Bevægeapparatets anatomi[Anatomy of the Locomotive Apparatus] (in Danish) (12th ed.). pp. 364–367.ISBN978-87-628-0307-7.
