Radio

Generality

The radius is the even bone which, together with the ulna (with respect to which it is in lateral position), forms the skeleton of each forearm.

Located between the humerus (above) and the carpal bones (below), it constitutes two essential joints for the movement of the entire upper limb: the elbow joint and the wrist joint.
To simplify the study, anatomists divide it into three portions: the proximal end (or proximal epiphysis), the body (or diaphysis) and the distal end (or distal epiphysis).
The proximal end is essential for articulating with the humerus; the body hosts numerous muscles of the forearm and of the hand, and finally the distal extremity is relevant for its union with the proximal carpal, scaphoid and semilunar bones.
Like any other bone in the human body, the radius can fracture as a result of trauma.

Definition

The radius is the even bone which, together with the ulna, makes up the skeleton of each forearm.
The forearm is the anatomical region of the upper limb between the upper arm and the lower hand.
Belonging to the category of long bones, the radius forms two important joints in the human body: one with the bone of the arm (the humerus), called the elbow joint, and another with the carpal bones of the hand, called the wrist joint. .

LOCATION WITH RESPECT TO THE ULNA

The radius runs parallel to the ulna, in a lateral position if the hand is facing with the palm towards the observer.
Readers who are unfamiliar with the concept of lateral (and its opposite meaning, i.e. medial), are advised to consult the explanation in the box below.