In human anatomy, plantar interossei muscles are three
muscles
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
located between the
metatarsal bone
The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...
s in the
foot
The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up o ...
.
Structure
The three plantar interosseous muscles are
unipennate, as opposed to the bipennate structure of dorsal interosseous muscles, and originate on a single metatarsal bone. The three muscles originate on the medial aspect of metatarsals III-V. The muscles cross the metatarsophalangeal joint of toes III-V so the insertions correspond with the origin and there is no crossing between toes.
The muscles then continue distally along the foot and insert in the proximal phalanges III-V. The muscles cross the metatarsophalangeal joint of toes III-V so the insertions correspond with the origin and there is no crossing between toes.
Innervation
All three plantar interosseous muscles are innervated by the lateral plantar nerve. The lateral plantar nerve is a branch from the tibial nerve, which originally branches off the sciatic nerve from the sacral plexus.
Function
Since the intersseous muscles cross on the metatarsophalangeal joint, then they act on that specific joint and cause adduction of toes III, IV, and V.
Adduction itself is not of extreme importance to the toes, but these muscles work together with the dorsal interosseous muscles in flexion of the foot. They also work together to strengthen the metatarsal arch.
Additional images
Image:Gray269.png, Bones of the right foot. Plantar surface.
File:Slide1ABBBA.JPG, Muscles of the sole of the foot.
See also
*
Interosseous muscles of the hand
**
Dorsal interossei of the hand
In human anatomy, the dorsal interossei (DI) are four muscles in the back of the hand that act to abduct (spread) the index, middle, and ring fingers away from the hand's midline (ray of middle finger) and assist in flexion at the metacarpophal ...
**
Palmar interossei
In human anatomy, the palmar or volar interossei (interossei volares in older literature) are four muscles, one on the thumb that is occasionally missing, and three small, unipennate, central muscles in the hand that lie between the metacarpal bo ...
*
Interosseous muscles of the foot
**
Dorsal interossei of the foot
In human anatomy, the dorsal interossei of the foot are four muscles situated between the metatarsal bones.
Origin
The four interossei muscles are bipenniform muscles each originating by two heads from the proximal half of the sides of adjacen ...
References
External links
PTCentral
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Foot muscles
Muscles of the lower limb