| Fifth metatarsal bone | |
|---|---|
 The fifth metatarsal. (Left.) | |
 Bones of the right foot. Dorsal surface. Fifth metatarsal bone is the yellow bone farthest the right | |
| Details | |
| Identifiers | |
| Latin | os metatarsale V |
| TA2 | 1502 |
| FMA | 24506 |
| Anatomical terms of bone | |
Thefifth metatarsal bone is along bone in the foot, and is palpable along thedistal outer edges of the feet. It is the second smallest of the fivemetatarsal bones. The fifth metatarsal is analogous to thefifth metacarpal bone in the hand.[1]
As with the four other metatarsal bones it can be divided into three parts; a 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 flat 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 articulates behind, by a triangular surface cut obliquely in atransverse direction, with thecuboid; and medially, with thefourth metatarsal. The fifth metatarsal has a rough eminence on the lateral side of its base, known as the tuberosity or the styloid process. The plantar surface of the base is grooved for the tendon of theabductor digiti quinti.
The head articulates with the fifthproximal phalanx, the first bone in the fifth toe.
A strong band of theplantar aponeurosis connects the projecting part of the tuberosity with the lateralprocess of the tuberosity of thecalcaneus.
Proximal fractures of the fifth metatarsal are common,[2] and are distinguished by their locations:
Normal anatomy that may simulate a fracture include mainly:
Thetendon of thefibularis tertius inserts on the medial part of the dorsal surface and thefibularis brevis on the dorsal surface of the tuberosity.
The plantar surface of the base is grooved for the tendon of theabductor digiti quinti, and gives origin to theflexor digiti minimi brevis.
The fourthdorsal interosseus muscle originates from the medial side of shaft. The function of the muscle is to spread the toes.[10]
The thirdPlantar interosseus muscle originates from the medial side of the base and shaft of the fifth metatarsal. The function of the muscle is to move the fourth toe medially and move the toes together.[10]
The horizontal head of theadductor hallucis from the deeptransverse metatarsal ligament,[10] a narrow band which runs across and connects together the heads of all the metatarsal bones.
| Muscle | Direction | Attachment[11] |
|---|---|---|
| Fibularis tertius | Insertion | Dorsal side of the basis |
| Fibularis brevis | Insertion | Tuberosity |
| Flexor digiti minimi brevis | Origin | Plantar surface of the base |
| Dorsal interossei IV | Origin | Medial side of the shaft |
| Plantar interossei III | Origin | Medial side of the base and shaft |
| Horizontal head ofadductor hallucis | Origin | Deeptransverse metatarsal ligament |
This article incorporates text in thepublic domain frompage 274 of the 20th edition ofGray's Anatomy(1918)
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