Posterior Forearm Muscles Flashcards
Brachioradialis Origin
Proximal portion of lateral supracondylar ridge of humerus and adjacent lateral intermuscular septum
Brachioradialis Insertion
Lateral side, distal end of the radius, proximal to the radial styloid process
Brachioradialis Innervation
Radial nerve (C5/C6)
Brachioradialis Action
Elbow flexion, with forearm in mid-supination / Mid-pronation
Extensor Carpi Radialis Longus Origin
Distal portion of supracondular ridge of humerus bone and lateral intermuscular septum
Extensor Carpi Radialis Longus Insterion
Doral surface, base of MC #2
Extensor Carpi Radialis Longus Innervation
Radial Nerve (C6/C7)
Extensor Carpi Radialis Longus Action
Wrist extension and radial deviation
Extensor Carpi Radialis Brevis Origin
Lateral Epicondyle of humerus through Common Extensor Tendon (CET); Lateral/radial collateral ligament of elbow; and adjacent intermuscular septum
Extensor Carpi Radialis Brevis Insertion
Dorsal surface, base of MC #2 and #3
Extensor Carpi Radialis Brevis Innervation
Deep Radial Nerve (C7/C8)
Extensor Carpi Radialis Brevis Action
Wrist extension, radial deviation
Extensor Digitorum Origin
Lateral epicondyle through common extensor tendon (CET) and adjacent intermuscular septum
Extensor Digitorum Insertion
Dorsal Digital Expansion (DDE) of fingers 2-5 (essentially inserting on the dorsal aspect of bases of middle and distal phalanges)
Extensor Digitorum Innervation
Posterior Interosseous Nerve (C7/C8)
Extensor Digitorum Action
Extension of fingers 2-5, wrist extension
Extensor Digiti Minimi Origin
Lateral epicondyle of humerus by common extensor tendon (CET) and adjacent intermuscular septum
Extensor Digiti Minimi Insertion
Dorsal Digital Expansion (DDE) of little finger-medial side
Extensor Digiti Minimi Innervation
Posterior Interosseous Nerve (C7/C8)
Extensor Digiti Minimi Action
Extension of 5th finger, assists with wrist extension
Extensor Carpi Ulnaris Origin
Humeral Head: Lateral Epicondyle of the humerus via Common Extensor Tendon (CET)
Ulnar Head: Posterior border of ulna by aponeurosis
Extensor Carpi Ulnaris Insertion
Base of MC #5, Medial side
Extensor Carpi Ulnaris Innervation
Posterior interosseous Nerve (C7/C8)
Extensor Carpi Ulnaris Action
Wrist extension, Ulnar deviation
Aconeus Origin
Posterior surface of the lateral epicondyle of the humerus
Aconeus Insertion
Lateral side of the olecranon process and upper posterior surface of ulna
Aconeus Innervation
Radial nerve (C6/C7/C8)
Aconeus Action
Abduction of ulna during pronation of forearm; assists with forearm extention
Supinator Origin
Humeral Head: Lateral epicondyle of the humerus bone by Common Extensor Tendon; Radial collateral ligament and annular ligament of radius
Ulnar head: Supinator crest of the ulna
Supinator Insertion
Lateral surface; Proximal 1/3 radius
Supinator Innervation
Posterior Interosseous Nerve (C6/7)
Supinator Action
forearm supination
ABductor Pollicis Longus Origin
Posterior surface of ulna and radius and interosseous membrane (upper portion of ulna and middle 1/3 of radius)
ABductor Pollicis Longus Insertion
Base of MC #1, lateral side
ABductor Pollicis Longus Innervation
Posterior Interosseous Nerve - PIN (C7/C8)
ABductor Pollicis Longus Action
Abduction of thumb at CM joint; Assists with thumb extension and radial deviation
Extensor Pollicis Brevis Origin
Posterior surface of radius (below Abductor pollicis longus) and interosseous membrane.
Extensor Pollicis Brevis Insertion
Base of proximal phalanx of thumb, dorsal surface
Extensor Pollicis Brevis Innervation
Posterior Interosseous Nerve ( C7/C8)
Extensor Pollicis Brevis Action
Extension of the thumb (at MP and CM joints) assists with wrist radial deviation.
Extensor Pollicis Longus Origin
Posterior surface, middle 1/3 of ulna and interosseous membrane
Extensor Pollicis Longus Insertion
Base of the distal phalanx of the thumb, dorsal side
Extensor Pollicis Longus Innervation
Posterior Interosseous Nerve, (C7/C8)
Extensor Pollicis Longus Action
Thumb extension at Ip, MP, and CM joints, rotates thumb laterally so pad is out.
Extensor Indicis Origin
Posterior surface of the ulna (distal to the EPL) and interosseous membrane
Extensor Indicis Insertion
Dorsal digital expansion. (DDE) of the index finger, medial side
Extensor Indicis Innervation
Posterior interosseous nerve (C7/C8)
Extensor Indicis Action
Extension of the index finger
Superficial Posterior Forearm Muscles
- Brachioradialis
- Extensor Carpi Radialis Longus
- Extensor Carpi Radialis Brevis
- Extensor Digitorum
- Extensor Digiti Minimi
- Extensor Carpi Ulnaris
- Anconeous
Deep Posterior Forearm Muscles
- Abductor pollicis Longus
- Extensor pollicis Brevis
- Extensor Pollicis Longus
- Supinator muscle
- Extensor indicis