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Innervation of the hand (afferent and efferent):
Afferent (sensory) innervation
Efferent (motor) innervation
All the intrinsic muscles of the hand are innervated by the
Ulnar nerve except for the "LOAF muscles"
Innervation of the foremarm (efferent):
Flexors of the wrist:
All but 2 (flexor carpi ulnaris and a component of flexor digitorum profundus) are innervated by median nerve.
Flexor carpi ulnaris - Innervated by the ulnar nerve
Flexor digitorum profundus - Innervated by both ulnar and median nerves
- Flexion at the DIP joints of index and middle fingers: median nerve (anterior
interosseus nerve which also innervates FPL, damaged during distal humeral
fractures leading to a positive OK sign).
- Flexion at the DIP joints of ring and little fingers: ulnar nerve
Extensors of the wrist (and hand):
All extensors of the wrist are innervated by the radial nerve (posterior interosseous branch).
Clinical significance:
Median nerve entrapment as it traverses through the carpal tunnely causes carpal tunnely syndrome.
Ulnar nerve injury
- Proximally in the elbow: Weakness, claw hand
- Distally: Claw hand worse symptoms - i.e. ulnar paradox
Author:
Mr Kasun Wanigasooriya MBCHB, MRCS
| Speciality:
Anatomy
| Date Added:
16/05/2010
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