Muscles of the Antebrachium : Extensors Flashcards
Extensor Carpi Radialis Longus
O : Distal 1/3 of lateral supracondylar ridge of the humerus
I : Posterior side of the base of the 2nd metacarpal
A :
1. Extends the hand at the wrist joint
2. Radially deviate the hand at the wrist joint
Extensor Carpi Radialis Brevis
O : Lateral epicondyle of the humerus via the common extensor tendon and the posterior middle 1/3 of the ulna
I : Posterior side of the base of the 5th metacarpal
A :
1. Extends the hand at the wrist joint
2. Ulnar deviates the hand at the wrist
Extensor Digitorum
O : Lateral epicondyle of the humerus via the common extensor tendon
I : Posterior surfaces of the middle and distal phalanges of digits 2-5
A :
1. Extend digits 2-5 at the MCP, PIP and DIP
2. Extends the hand at the wrist joint
Extensor Indicis
O : Distal 1/3 of the posterior ulna and interosseous membrane
I : Ulnar side of the extensor digitorum to attach to middle and distal phalanges of the 2nd digits via the dorsal digital expansion
A :
1. Extends the index fingers at MCP, PIP and DIP
2. Extends the hand at the wrist joint
Extensor Digiti Minimi
O : Lateral epicondyle of the humerus via the common extensor tendon
I : Ulnar side of extensor digitorum to attach to middle and distal phalanges of the 5th digit via dorsal digital expansion
A :
1. Extends the 5th digit at MCP, PIP and DIP
Extensor Pollicis Brevis
O : Posterior 1/3 of the distal radius and interosseous membrane
I : Posterolateral base of the proximal phalanx of the thumb
A :
1. Extend the thumb at CMC and MCP
2. Abducts the thumb at CMC
Abductor Pollicis Longus
O : Posterior 1/3 of the middle surface of the radius, ulna and interosseous membrane
I : Base of the 1st metacarpal
A :
1. Abduct the thumb at CMC joint
2. Extends the thumb at CMC joint
Extensor Pollicis Longus
O : Posterior middle 1/3 of the ulna and interosseous membrane
I : Base of the distal phalanx of the thumb via dorsal digital expansion
A : Extends the thumb at the CMC, MCP and IP
