First metatarsal bone

Source: Wikipedia, the free encyclopedia.
First metatarsal bone
The first metatarsal. (Left.)
Bones of the right foot. Dorsal surface. The first metatarsal bone is shown in yellow farthest to the left
Details
Identifiers
Latinos metatarsale I
TA21500
FMA24502
Anatomical terms of bone

The first metatarsal bone is the

metatarsal bones and by far the thickest and strongest of them.[1]

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).[1]

The base presents, as a rule, no

second metatarsal. On the lateral part of the plantar surface there is a rough oval prominence, or tuberosity, for the insertion of the tendon of the fibularis longus
.

The first metatarsal articulates (forms

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

Muscle attachments

Muscle attachments (seen from above)
Muscle attachments (seen from below)

Three muscles attach to the first metatarsal bone: the tibialis anterior, fibularis longus and first dorsal interosseus.[3]

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.[4]

Muscle Direction Attachment[3]
Tibialis anterior Insertion Basis of first metatarsal
Fibularis longus Insertion Tuberosity of first metatarsal
Dorsal interossei I Origin Lateral part of first metatarsal

Additional images

  • Sesamoid bones at the distal end of the first metatarsal.
    Sesamoid bones at the distal end of the first metatarsal.
  • First metatarsal bone. Deep dissection.
    First metatarsal bone. Deep dissection.
  • It is common in children to have a pseudo-epiphysis of the first metatarsal.[5]
    It is common in children to have a
    pseudo-epiphysis of the first metatarsal.[5]

References

Public domain This article incorporates text in the public domain from page 272 of the 20th edition of Gray's Anatomy (1918)

  1. ^
    ISBN 978-87-628-0307-7
    .
  2. ^ Platzer 2004, p. 218
  3. ^
    ISBN 978-87-628-0307-7
    .
  4. ISBN 978-87-628-0307-7
    .
  5. PMID 2681682
    .
Wikimedia Commons has media related to First metatarsal bone.
Retrieved from "https://en.wikipedia.org/w/index.php?title=First_metatarsal_bone&oldid=1201854375"