Lunate bone Lunate bone The lunate bone (semilunar bone) is a carpal bone in the human hand. It is distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row carpal bones, which lie between the ulna and radius and the hand. The lunate carpal bone is situated between the lateral scaphoid bone and medial triquetral bone. The lunate is a crescent-shaped carpal bone found within the hand. The lunate is found within the proximal row of carpal bones. Proximally, it abuts the radius. Laterally, it articulates with the scaphoid, medially with the triquetral, and
Posterior compartment of the forearm tumour. In the superfamily hominoidea or apes, configurations of the muscles of the posterior compartment of the forearm share similar characteristics. However, the anconeus is usually not present in the hylobates (gibbons). Also, the extensor pollicis brevis is only present in the genus homo (humans) and the genus hylobates because the extensor pollicis brevis and the abductor pollicis longus exist as a single muscle in other genera. Posterior compartment of the forearm The posterior compartment of the forearm (or extensor compartment) contains twelve muscles which are chiefly responsible for extension of the wrist and digits, and supination of the forearm.