<P> In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus . The bones of the carpus do not belong to individual fingers (or toes in quadrupeds), whereas those of the metacarpus do . The corresponding part of the foot is the tarsus . The carpal bones allow the wrist to move and rotate vertically . </P> <P> In human anatomy, there are 8 carpal bones which can be classified as either belonging to two transverse rows, or three longitudinal columns . </P> <P> The pair of rows together form an arch which is convex proximally and concave distally . On the palmar side, the carpus is concave, forming the carpal tunnel which is covered by the flexor retinaculum . Because the proximal row is simultaneously related to the articular surfaces of the radius and the distal row, it adapts constantly to these mobile surfaces . The bones of this row - scaphoid, lunate, and triquetrum - have their individual movements . The scaphoid contributes to the stability of the midcarpus as it articulates distally with the trapezium and the trapezoid . The distal row is more rigid as its transverse arch moves with the metacarpals . </P> <P> Biomechanically and clinically, the carpal bones are better understood as arranged in three longitudinal columns: </P>

The proximal row of carpal bones consists of what bones