The ulna is the medial bone of the forearm, on the little finger side. Its proximal end forms the hinge of the elbow with the trochlea of the humerus through the trochlear notch between the olecranon and coronoid process. Its distal end is small and articulates with the radius.
| Type | Long bone. |
|---|---|
| Location | Medial (little finger side) forearm. |
| Landmarks | Olecranon, coronoid process, trochlear notch, radial notch, ulnar tuberosity, head, styloid process. |
| Articulations | Humerus (elbow), radius (proximal and distal radioulnar joints). |
| Muscle attachments | Triceps, brachialis, flexor digitorum profundus, flexor carpi ulnaris, pronator quadratus. |
3D model: BodyParts3D (CC BY 4.0), adult male reference anatomy. Highlighted structure shown with nearby bones for context.
The olecranon forms the point of the elbow. The ulna stays relatively fixed during pronation and supination while the radius rotates around it.
The olecranon process of the ulna.
The elbow joint with the humerus and the proximal and distal radioulnar joints with the radius.
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