Forearm Muscles Flashcards
Pronator teres (PT)
O: Humeral head- medial supracondylar ridge to medial epicondyle of humerus via common flexor tendon (CFT)
Ulnar head- Coronoid process of ulna, medial aspect
I: Lateral midshaft of radius
N: Median nerve (C6+7)
A: Forearm pronation and elbow flexion
Flexor carpii radialis (FCR)
O: Humerus- CFT
I: Anterior base of MC 2 with slip to MC 3
N: Median n. (C7+8)
A: Wrist flexion and radial deviation, forearm pronation, elbow flexion
Palmaris longus (PL)
O: Humerus- CFT
I: Palmar aponeurosis
N: Median n. (C6+7)
A: Wrist flexion, tenses palmar fascia
Flexor carpi ulnaris (FCU)
O: Humeral head- Humerus (CFT)
Ulnar head- medial aspect of olecranon process to posterior border (upper 2/3) by common aponeurosis with FDP + ECU
I: Pisiform to hook of hamate via pisohamate ligament and pisiform to base of MC5 by pisometacarpal ligament
N: Ulnar nerve (C8)
A: Wrist flexion and ulnar deviation, elbow flexion
Flexor digitorum superficialis (FDS)
O: Humeral head- Humerus (CFT)
Ulnar head- Medial aspect coronoid process of ulna to ulnar collateral ligament of elbow
Radial head- Upper 1/2 anterior border of radius
I: Middle phalanges 2-5 to mid shaft via split tendons
N: Median nerve (C7+8)
A: Finger flexion at MPs and PIPs 2-5, wrist flexion, and elbow flexion
Flexor digitorum profundus (FDP)
O: Proximal 3/4 anterior and medial surfaces of ulna to posterior border (upper 3/4) by common aponeurosis with FCU + ECU
I: Distal phalanges 2-5 to anterior bases
N: Anterior intermissions n. (AIN) for digits 2+3; Ulnar n. for digits 4+5 [C8T1]
A: Finger flexion at MPs, PIPs, and DIPs 2-5, wrist flexion.
Flexor pollicis longus (FPL)
O: Mid anterior surface of radius, distal to anterior oblique line
I: Anterior base of distal phalanx 1
N: AIN (C8T1)
A: Thumb flexion at CM, MP, and IP joints, wrist flexion
Pronation quadratus (PQ)
O: Distal 1/4 anterior surface of ulna
I: Distal 1/4 anterior surface of radius
N: AIN (C8T1)
A: Forearm pronation
Brachioradialis (BR)
O: lateral supracondylar ridge of humerus, proximal 2/3 and anterior surface of lateral intermuscular septum
I: Lateral side of radius, distal end near base of styloid process
N: Radial n. (C5+6)
A: Elbow flexion, especially with forearm in mid-pronation/supination position
Extensor Carpi Radialis Longus (ECRL)
O:Lateral supracondylar ridge of humerus, distal 1/3 and lateral intermuscular septum
I: posterior base of MC 2
N: Radial nerve - above elbow ( C6+7)
A: Wrist extension, hyperextension, and radial deviation
Extensor carpi radialis brevis (ECRB)
O: lateral epicondyle of humerus via the CET
I: MC 3 - posterior base, with slip to MC 2
N: Deep radial nerve (C6+7)
A: Wrist extension, hyperextension, and radial deviation
Extensor digitorum (ED)
O: Humerus - CET
I: Dorsal digital expansions (DDEs) 2-5
N: PIN (C7+8)
A: Finger extension at MPs 2-5. Wrist extension, hyperextension
Extensor digiti minimi (EDM)
O: Humerus - CET
I: DDE 5, medial side of ED
N: PIN (C7+8)
A: Finger extension MP 5. Wrist extension, hyperextension
Extensor carpi ulnaris (ECU)
O: Humeral head- Humerus (CET)
Ulnar head- Posterior border of ulna by common aponeurosis with FCU + FDP
I: MC 5, medial base
N: PIN (C7+8)
A: Wrist extension, hyperextension, and ulnar deviation
Supinator
O: Humeral head- Humerus (CET)
Ulnar head- Supinator fossa and crest of radius
I: Proximal 1/3 lateral surface of radius
N: Deep radial n. (C5+6)
A: Forearm supination
Abductor pollicis longus (APL)
O: Upper posterior surface of ulna, mid 1/3 posterior surface of radius, IOM
I: MC 1, lateral base
N: PIN (C7+8)
A: Thumb abduction and extension at CM joint. Wrist radial deviation
Extensor pollicis brevis (EPB)
O: Radius- mid 1/3 posterior surface, below APL IOM
I: Proximal phalanx 1, posterior base
N: PIN (C7+8)
A: Thumb extension at MP joint. Wrist radial deviation
Extensor pollicis longus (EPL)
O: Ulna - mid 1/3 posterior surface IOM
I: Distal phalanx 1, posterior base
N: PIN (C7+8)
A: Thumb extension at CM, MP and IP joints. Wrist radial deviation
Extensor indicis (EI)
O: Ulna, distal 1/3 posterior surface, below EPL IOM
I: DDE 2, medial side of ED
N: PIN (C7+8)
A: Finger extension MP 2. Wrist extension, hyperextension
