The phalanges of the hand are commonly known as the finger bones. They are fourteen in number, three for each finger, and two for the thumb on each hand. The names of the phalanges of the three rows of finger bones, from the hand out, are; proximal, intermediate and distal phalanges, while the thumb only contains a proximal and distal phalanx. The body tapers from above downward, is convex posteriorly, concave in front from above downward, flat from side to side; its sides are marked by rough areas which give attachment to the fibrous sheaths of the flexor tendons. The proximal extremities of the bones of the first row present oval, concave articular surfaces, broader from side to side than from front to back. The proximal extremity of each of the bones of the second and third rows presents a double concavity separated by a median ridge. The distal extremities are smaller than the proximal, and each ends in two condyles (knuckles) separated by a shallow groove; the articular surface extends farther on the palmar than on the dorsal surface, a condition best marked in the bones of the first row.