Forearm - Posterior, Superficial
Key Summary
- Most superficial extensors arise from the lateral epicondyle of humerus.
- Exception is extensor carpi radialis, which arises from the supracondylar ridge of the humerus.
- The superficial muscles of the posterior forearm are innervated by the radial nerve.
- Originates on the lateral side of the humerus (specifically, from the supracondylar ridge).
- Inserts on the base of metacarpal II.
- Extends and abducts the hand.
- Inserts on the base of metacarpal III.
- It extends and abducts the hand.
- Gives rise to the extensor tendons, which has lateral and central bands
- Lateral bands of the tendons insert on the bases of the distal phalanges of digits 2-5.
- Central bands of the tendons insert on the middle phalanges of digits 2-5.
- Extends digits 2-5 and the hand.
- Inserts into the extensor expansion on the middle phalanx of digit 5
- It extends this digit 5 (along with extensor digitorum).
- Inserts on the base of metacarpal V.
- It extends and adducts the hand.