Forearm Flashcards
Anterior Compartment of forearm
Flexors/Pronators
innervate by median n., anterior interosseous n., and ulnar n.
Superficial Muscles of the Anterior Compartment
Pronator Teres
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris
Intermediate Muscles of the Anterior Compartment
Flexor Digitorum Superficialis
Posterior Muscles of the Anterior Compartment
Flexor Digitorum Profundas
Flexor Pollicis Longus
Pronator Quadratus
Pronator Teres
Proximal attachment = coronoid process and medial epicondyle
Distal attachment = middle convexity of lateral surface of radius
Innervated by median n. (C6, C7)
Pronates the radius on the ulna
Flexor Carpi Radialis
Proximal attachment = medial epicondyle
Distal attachment = base of the 2nd metacarpal
Innervated by median n. (C6, C7)
Flexes and abducts the hand on the radial side (thumb side)
- Pure abduction uses FCR and ECR simultaneously
- Pure flexion uses FCU and FCR simultaneously
Palmaris Longus
Proximal attachment = medial epicondyle
Distal attachment = apex of palmar aponeurosis and distal half of flexor retinaculum
Innervated by median n. (C6, C7)
Flexes hand at wrist and tenses palmar aponeurosis
Flexor Carpi Ulnaris
Proximal attachment = medial epicondyle, olecranon, and posterior border of ulna
Distal attachment = 5th metacarpal, the hook of hamate, and pisiform
Innervated by ulnar n. (C7, C8)
Flexes and adducts the hand on the ulnar side
Flexor Digitorum Superficiailis
Proximal attachment = medial epicondyle and superiro half of anterior border of radius
Distal attachment = shafts of middle phalanges of medial four digits
Innervated by median n.
Flexes intermediate phalanges, NOT distal phalanges
Flexor Digitorum Profundas
Proximal attachment = proximal 3/4 of anterior and medial surfaces of ulna and interosseous membrane
Distal attachment = distal phalanges
Innervation:
-Radial half (digits 2 and 3) is innervated by anterior interosseous n. (a branch of the median n.)
-Ulnar half (digits 4 and 5) is innervated by the ulnar n.
Flexor Pollicis Longus
Proximal attachment = anterior surface of radius and interosseous membrane
Distal attachment = base of distal phalanx of thumb
Innervated by anterior interosseous n. (C8, T1)
Long flexor of the thumb (pollicis)
Pronator Quadratus
Proximal attachment = distal 1/4 of anterior surface of ulna
Distal attachment = distal 1/4 of anterior surface of radius
Innervated by anterior interosseous n. (C8,T1)
Pronator of distal radioulnar joint and binds radius and ulna
Posterior Compartment
Extensor/Supinator Compartment
Innervated by radial n. (C5-T1), deep branch of the radial n., and posterior interosseous n.
Superficial Layer of Posterior Compartment
Brachioradialis Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Digitorum Extensor Digiti minimi Extensor Carpi Ulnaris
Deep Layer of Posterior Comparment
Supinator Extensor Indicis Abductor Pollicis Longus Extensor Pollicis Longus Extensor Pollicis Brevis
Brachioradialis
Proximal attachment = proximal 2/3 of lateral supraepicondylar ridge of humerus
Distal attachment = lateral surface of distal end of radius, proximal to styloid process
Innervated by radial n. proper
Flexor of the elbow only
*does NOT cross the radiocarpal (wrist) joint
Extensor Carpi Radialis Longus
Proximal attachment = lateral supraepicondylar ridge of humerus
Distal attachment = dorsal aspect of 2nd metacarpal
Innervated by radial n. proper
Extends hand and abducts hand on radial side at the wrist joint
Contributes to flexion of elbow
Extensor Carpi Radialis Brevis
Proximal attachment = lateral epicondyle of humerus
Distal attachment = dorsal aspect of 3rd metacarpal
Innervated by deep branch of radial n.
Extends hand on radial side and abducts hand at the wrist joint
ECRL and ECRB act with the FCR to perform pure abduction of the wrist
Extensor Digitorum
Proximal attachment = lateral epiconyle
Distal attachment = extensor expansions of medial four digits
Innervated by deep branch of the radial n.
Extends the medial four digits (digits 2-5) at MCPs and secondarily at IPs
Extensor Digit Minimi
Proximal attachment = lateral epicondyle
Distal attachment = extensor expansion of 5th digit
Innervated by deep branch of the radial n.
Extends 5th digit at MCP, secondarily at IP
Extensor Carpi Ulnaris
Proximal attachment = lateral epicondyle and psoterior border of ulna through a shared aponeurosis
Distal attachment = dorsal aspect of base of 5th metacarpal
Innervated by deep branch of the radial n.
Extends hand on ulnar side and adducts hand at wrist joint, and acts with the FCU, to purely adduct the wrist
Supinator
Proximal attachment = lateral epicondyle, the radial and ulnar collateral ligaments, supinator fossa, and crest of ulna
Distal attachment = lateral, posterior, and anterior surfaces of proximal 1/3 of radius
Innervated by deep branch of the radial n. (deep branch pierces the supinator m.
Main supinator of the forearm (with biceps brachii m.)
Extensor indicis
Proximal attachment = posterior surface of distal 1/3 of ulna and interosseous membrane
Distal attachment = extensor expansion of 2nd digit
Innervated by posterior interosseous n.
Extends 2nd digit
Abductor Pollicis Longus
Proximal attachment = proximal halves of ulna, radius, and interosseous membrane
Distal attachment = base of 1st metacarpal
Innervated by posterior interosseous n.
Abduct thumb and extend thumb at CMC joint
Extensor Pollicis Longus
Proximal attachment = posterior surface of middle 1/3 of ulna and interosseous membrane
Distal attachment = dorsal aspect of base of distal phalanx of thumb
Innervated by posterior interosseous n.
Extends distal phalanx at IP, extends MCP and CMC
Extensor Pollicis Brevis
Proximal attachment = posterior surface of distal 1/3 of radius and interosseous membrane
Distal attachment = dorsal aspect of base of proximal phalanx of thumb
Innervated by posterior interosseuous n.
Extends proximal phalanx of thumb at MCP and extends CMC
