Intercarpal joints intercarpal ligaments are two narrow bundles, one connecting the lunate with the scaphoid, the other joining it to the triangular. They are on a level with the superior surfaces of these bones, and their upper surfaces are smooth, and form part of the convex articular surface of the wrist-joint. The ligaments connecting the pisiform bone are the articular capsule and the two volar ligaments. The articular capsule is a thin membrane which connects the pisiform to the triangular; it is lined by synovial membrane. The two volar ligaments are strong fibrous bands; one, the pisohamate ligament, connects the pisiform to
Carpal bones with a total range of 170 degrees. During radial abduction the scaphoid is tilted towards the palmar side which allows the trapezium and trapezoid to approach the radius. Because the trapezoid is rigidly attached to the second metacarpal bone to which also the flexor carpi radialis and extensor carpi radialis are attached, radial abduction effectively pulls this combined structure towards the radius. During radial abduction the pisiform traverses the greatest path of all carpal bones. Radial abduction is produced by (in order of importance) extensor carpi radialis longus, abductor pollicis longus, extensor pollicis longus, flexor carpi radialis, and flexor pollicis