Plantar interphalangeal ligaments

The former term 'plantar plate'refered to:

• the plantar metatarsophalangeal ligaments,
• the plantar interphalangeal ligaments,
• the palmar metacarpophalangeal ligaments,
• and the palmar interphalangeal ligaments

Their proximal origins are thin but the distal insertions are stouts.

Due to the weight-bearing nature of the human foot, the plantar plates are exposed to extension forces not present in the human hand.

The plantar plate supports the weight of the body and restricts dorsiflexion, whilst the main collateral ligament and the accessory collateral ligament (together referred as the collateral ligament complex, CLC) prevent motions in the transverse and sagittal planes.

The major difference between the plantar plates of the MTP and IP joints is that they blend with the transverse metatarsal ligament in the MTP joints (not present in the toes).

The MTP joint of the first toe differs from those of the other toes in that other muscles act on the joint, and in the presence of two sesamoid bones.

The plantar plate is firm but flexible fibrocartilage with a composition similar to that found in the menisci of the knee (composed roughly of 75% type-I collagen), and can thus withstand compressive loads and act as a supportive articular surface.

Most of its fibers are oriented longitudinally, in the same direction as the plantar fascia, and the plate can thus sustain substantial tensile loads in this direction.