Description: the medial bone of the forearm (when in anatomical position).

The interosseus membrane connects the shafts of the radius and ulna and stabilizes the radioulnar joints.The proximal ends of the radius and ulna articulate with the distal humerus to form the elbow joint.

The radioulnar joints are responsible for forearm pronation and supination.

They articulate with each other at the proximal and distal radioulnar joints.

The bones of the forearm are the radius and ulna.

The forearm is the portion of the upper limb between the elbow and wrist joint.

They are drained by the superficial cephalic and basilic veins and the deep radial and ulnar veins. The forearm, the wrist, and the hand are perfused by the radial and ulnar artery and their branches. The intrinsic muscles of the hand are responsible for hand and finger movement and consist of the thenar, hypothenar, lumbrical, and interossei muscles. Both groups of muscles are also involved in the abduction and adduction of the wrist. The flexor group of muscles is involved in pronation of the forearm and flexion of the wrist and fingers, while the extensor group of muscles is involved in supination of the forearm and extension of the wrist and fingers. The forearm (lower arm or antebrachium) has an anterior compartment, which consists of the flexor group of muscles and is innervated by the ulnar and median nerve, and a posterior compartment, which consists of the extensor group of muscles and is innervated by the radial nerve. Distally, the carpus articulates with the metacarpal bones, which, together with the phalanges, make up the bones of the hand. The carpus is the complex of eight carpal bones ( scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate), while the radiocarpal joint is the region of articulation between the carpus and radius. The wrist is comprised of the carpus and the radiocarpal joint.

Hand extensor compartments