The interphalangeal joints of the foot are the
joint
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...
s between the
phalanx bones of the
toes in the
feet.
Since the
great toe only has two phalanx bones (
proximal and distal phalanges), it only has one interphalangeal joint, which is often abbreviated as the "IP joint". The rest of the toes each have three phalanx bones (proximal, middle, and distal phalanges), so they have two interphalangeal joints: the proximal interphalangeal joint between the proximal and middle phalanges (abbreviated "PIP joint") and the distal interphalangeal joint between the middle and distal phalanges (abbreviated "DIP joint").
All interphalangeal joints are
ginglymoid (hinge) joints, and each has a
plantar (underside) and two
collateral ligament
A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...
s. In the arrangement of these ligaments,
extensor tendons supply the places of
dorsal
Dorsal (from Latin ''dorsum'' ‘back’) may refer to:
* Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism
* Dorsal, positioned on top of an aircraft's fuselage
The fus ...
ligaments, which is similar to that in the
metatarsophalangeal articulations.
Movements
The only movements permitted in the joints of the digits are
flexion
Motion, the process of movement, is described using specific anatomical terminology, anatomical terms. Motion includes movement of Organ (anatomy), organs, joints, Limb (anatomy), limbs, and specific sections of the body. The terminology used de ...
and
extension; these movements are more extensive between the first and second phalanges than between the second and third. The
flexor hallucis longus
The flexor hallucis longus muscle (FHL) attaches to the plantar surface of phalanx of the great toe and is responsible for flexing that toe. The FHL is one of the three deep muscles of the posterior compartment of the leg, the others being the ...
and
flexor digitorum longus flex the interphalangeal joint of the big toe and lateral four toes, respectively. The tendons of both of these muscles cross as they reach their distal attachments. In other words, the flexor hallucis longus arises laterally, while the flexor digitorum longus arises medially.
The amount of flexion is very considerable, but extension is limited by the
plantar and
collateral ligaments.
See also
*
Interphalangeal joints of hand
*
Metatarsophalangeal joints
References
Joints
Foot
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