Extensors of the forearm Flashcards
Superficial Extensor Muscle Group
Brachioradialis Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Digiti Minimi Extensor Carpi Ulnaris Anconeous
Origin of the Brachioradialis
Upper lateral supracondylar ridge of the humerus
Insertion of the Brachioradialis
Lateral radius above styloid process
innervation of any extensor muscle
radial nerve
Action of the Brachioradialis
- Flexion of the elbow when in a neutral position
- Supination when the arm is pronated
- Pronation when the arm is supinated
Origin of the Extensor Carpi Radialis Longus
Lower lateral supracondylar ridge of the humerus
Insertion of the Extensor Carpi Radialis Longus
Base of the 2nd metacarpal
Action of the Extensor Carpi Radialis Longus
Wrist extension
-Radial deviation (with the flexor carpi radialis)
Origin of the Extensor Carpi Radialis Brevis
Lateral epicondyle of the humerus
Insertion of the Extensor Carpi Radialis Brevis
Base of 3rd metacarpal
Action of the Extensor Carpi Radialis Brevis
Wrist extension
Origin of the Extensor Digitorum
Lateral epicondyle of humerus
Insertion of the Extensor Digitorum
Extensor hood
Action of the Extensor Digitorum
-Extension of all finger joints
Origin of the Extensor Digiti Minimi
Lateral epicondyle
Insertion of the Extensor Digitorum Minimi
Extensor hood of 5th finger
Action of the Extensor Digiti Minimi
Extension of 5th finger
Origin of the Extensor Carpi Ulnaris
Lateral epicondyle of humerus
Insertion of the Extensor Carpi Ulnaris
Base of 5th metacarpal
Deep Extensor Muscle Group
Supinator Abductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus Extensor Indicis
Origin of the Supinator
- Lateral epicondyle of humerus
- Annular ligament
- Superior crest of the ulna
Insertion of the Supinator
Upper radius
Action of the Supinator
Supinates the forearm
Origin of the Abductor Pollicis Longus
- Posterior ulna
- Posterior radius
- Interosseous membrane
Insertion of the Abductor Pollicis Longus
Base of the 1st metacarpal
Action of Abductor Pollicis Longus
Abducts the thumb
Origin of the Extensor Pollicis Brevis
- Distal radius
- Interosseous membrane
Insertion of the Extensor Pollicis Brevis
Base of the proximal phalanx of the thumb
Action of the Extensor Pollicis Brevis
Extends MCP joint of thumb
Origin of the Extensor Pollicis Longus
- Posterior ulna
- Interosseous membrane
Insertion of the Extensor Pollicis Longus
Base of the distal phalanx of the thumb
Action of the Extensor Pollicis Longus
Extends the thumb
Origin of the Extensor Indicis
Posterior distal ulna
Insertion of the Extensor Indicis
Extensor hood on index finger
Action of the Extensor Indicis
Extension of index finger
carpi means
wrist
pollicis means
thumb
indices
index finger
3 radial extensor muscles
brachioradialis
extensor carpi radialis longus
extensor carpi radialis brevis
3 digit extensor muscles
extensor digitorum
extensor indicis
extensor digiti minimi
3 pollicis extensor muscles
extensor pollicis longus
extensor pollicis brevis
abductor pollicis longus
tendons and blood supply of anatomical snuff box
tendons - extensor pollicis longus, brevis, abductor pollicis longus
blood supply - cephalic vein, radial artery
3 other extensor muscles
extensor carpi ulnaris
anconeus
supinator