In the human foot, the plantar or volar plates (also called plantar or volar ligaments) are fibrocartilaginous structures found in the metatarsophalangeal (MTP) and interphalangeal (IP) joints. The anatomy and composition of the plantar plates is similar to the palmar plates in the metacarpophalangeal (MCP) and interphalangeal joints in the hand; the proximal origin is thin but the distal insertion is stout. 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.
... At the metatarsophalangeal joint the plantar plate plays an important role in the foot's weight-bearing function ... The plantar plate is attached to the proximal phalanx, to the major longitudinal bands of the plantar fascia, and to the collateral ligaments ... The plate from the substantial distal insertion of the plantar fascia and can withstand tensile loads in line with the fascia itself ...
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