Upper limb
Extensor Carpi Radialis Longus
Musculus extensor carpi radialis longus
- Origin
- Lateral supracondylar ridge of the humerus
- Insertion
- Base of the second metacarpal bone
- Function
- Extends the wrist and moves it into radial deviation
- Innervation
- Radial nerve, C6–C7
- Movement & chain
- Forms a pair with extensor carpi ulnaris for radial deviation; stabilizes the wrist in extension during powerful finger grasping movements.
- Palpation
- Palpable on the radial side of the proximal forearm, just distal to the lateral epicondyle, during resisted wrist extension with radial deviation.
- Clinical
- Along with extensor carpi radialis brevis, involved in tennis elbow complaints.
- Segmental innervation
- Part of the C6–C7 myotome; the only wrist extensor innervated directly by the radial nerve (before it splits into the deep branch), which can leave it relatively spared in a posterior interosseous nerve lesion.
- In clinical practice
- Focus on hand function and edema prevention; ensure IV cannulas and splints maintain functional hand position to prevent joint contractures.
- Region in the model
- Upper limb