Structure
This fibrocartilaginous structure is attached to the base of the proximal phalanx distal to the joint. From there, it forms a palmar continuation of the articular surface of the phalanx bone and its inner surface thus adds to the articular surface during extension.
In its proximal end, the volar plate becomes membranous and blends with the volar capsule which is attached to the head of the metacarpal bone. During flexion, the plate glides proximally down the volar surface of the metacarpal head. Its flexible attachment to the phalanx bone not only prevents it from restricting joint movements, but also prevents the long flexor tendons from being pinched in the joint. Flexion of the proximal phalanx is facilitated by the shape of the proximal edge, known as the volar recess, but this diaphanous end of the volar plate is also the part of the metacarpophalangeal joint that is most susceptible to injury during dislocations.
Due to its fibrocartilaginous composition, the plate is thus able to (1) resist tensile stresses while (2) restricting hyperextension and compression and (3) protecting the volar articular surface.
Read more about this topic: Palmar Plate
Famous quotes containing the word structure:
“If rightly made, a boat would be a sort of amphibious animal, a creature of two elements, related by one half its structure to some swift and shapely fish, and by the other to some strong-winged and graceful bird.”
—Henry David Thoreau (1817–1862)
“I’m a Sunday School teacher, and I’ve always known that the structure of law is founded on the Christian ethic that you shall love the Lord your God and your neighbor as yourself—a very high and perfect standard. We all know the fallibility of man, and the contentions in society, as described by Reinhold Niebuhr and many others, don’t permit us to achieve perfection.”
—Jimmy Carter (James Earl Carter, Jr.)
“The structure was designed by an old sea captain who believed that the world would end in a flood. He built a home in the traditional shape of the Ark, inverted, with the roof forming the hull of the proposed vessel. The builder expected that the deluge would cause the house to topple and then reverse itself, floating away on its roof until it should land on some new Ararat.”
—For the State of New Jersey, U.S. public relief program (1935-1943)