an Entity references as follows:
The metacarpophalangeal joints (MCP) are situated between the metacarpal bones and the proximal phalanges of the fingers. These joints are of the condyloid kind, formed by the reception of the rounded heads of the metacarpal bones into shallow cavities on the proximal ends of the proximal phalanges. Being condyloid, they allow the movements of flexion, extension, abduction, adduction and circumduction at the joint.