Posterior Forearm Flashcards
What nerves provide cutaneous innervation to the posterior forearm?
Supraclavicular nn. Axillary n. Radial n. Medial brachial cutaneous n. Medial antebrachial cutaneous n. Intercostobrachial n. Ulnar n. Proper palmar digital nn. (Median n.)
What 6 muscles are present in the superficial group of the posterior forearm?
Brachioradialis m. Extensor carpi radialis longus m. Extensor carpi radialis brevis m. Extensor digitorum longus m. Extensor digiti minimi m. Extensor carpi ulnaris m.
What 4 muscles are present in the deep group of the posterior forearm?
Supinator m.
Abductor pollicis longus m.
Extensor pollicis longus m.
Extensor indicis m.
ALL muscles of the posterior forearm are innervated by what nerve?
Radial n.
ALL muscles of the posterior forearm are innervated by the radial n. via what branches?
Deep branch or posterior interosseous nerve branch
Origin of brachioradialis m.
Supraepicondylar ridge of humerus
Insertion of brachioradialis m.
Lateral distal radius, proximal styloid process
Action of brachioradialis m.
Weak arm flexion; maximal when mid-pronated
Innervation of brachioradialis m.
Superficial branch of radial n.
Origin of extensor carpi radialis longus
Lateral supraepicondylar ridge of humerus
Insertion of extensor carpi radialis longus m.
Dorsal side of 2nd metacarpal
Action of extensor carpi radialis longus m.
Extends/abducts hand at wrist
Origin of extensor carpi radialis brevis m.
Lateral epicondyle of humerus
Insertion of extensor carpi radialis brevis m.
Dorsal base of 3rd metacarpal
Action of extensor carpi radialis brevis m.
Extends/abducts hand at wrist (same as extensor carpi radialis longus m.)
Origin of extensor carpi ulnaris m.
Lateral epicondyle; posterior ulna via shared aponeurosis
Insertion of extensor carpi ulnaris m.
Dorsal base of 5th metatarsal
Action of extensor carpi ulnaris m.
Extends and adducts hand at wrist
Origin of extensor digitorum m.
Lateral epicondyle
Insertion of extensor digitorum m.
Extensor expansion of medial 4 digits
Action of extensor digitorum m.
Extends primarily at MPJ, but also at IPJ
[also has some wrist extension function]
Origin of extensor digiti minimi m.
Lateral epicondyle
Insertion of extensor digiti minimi m.
Extensor expansion of 5th digit
Action of extensor digiti minimi m.
Extends 5th digit at MPJ but also at IPJ
Origin of supinator m.
Deep part = ulna
Superficial part = lateral condyle
Insertion of supinator m.
Radial tubercle; oblique line of radius
Action of supinator
Supinates forearm