The radius is one of the two long bones present in the forearm. It is located laterally in the supinated anatomic position. It has a smaller proximal end and enlarges to a larger distal end (opposite to the ulna). 

The proximal radius comprises the radial head and immediately distally is the radial neck, and tuberosity.

The radial shaft is thicker than the ulna and becomes thicker distally.  It has a triangular cross section, with a lateral convexity, and a sharp medial (interosseous) border.

The distal radial shaft flares out to form the distal radius with a facet for articulation with most of the proximal carpal row. Laterally, there is the radial styloid and medially the ulnar notch. On the dorsal margin of the distal radius, Lister's tubercle (dorsal tubercle) separates the 2nd (ECRB and ECRL)  and 3rd (EPL) extensor compartments.

  • proximal
    • radial head: capitellum of the humerus (elbow flexion and extension)
    • radial head: radial notch of the proximal ulna (site of supination and pronation)
  • distal
    • distal radius facet: scaphoid and lunate fossae separated by a small ridge
    • ulnar notch: ulna head (site of supination and pronation)
Anatomy: Upper limb
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Article information

rID: 29037
Section: Anatomy
Synonyms or Alternate Spellings:
  • Radius bone
  • Radius anatomy
  • Radial anatomy

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