muscles of the forearm & hand Flashcards
compartment of the forearm
anterior compartment:
- superficial
- intermediate
- deep
posterior compartment
- superficial
- deep
4 anterior superficial muscles
- pronator teres
- flexor carpi radialis
- palmaris
- flexor carpi ulnaris
anterior intermediate muscle
- flexor digitorum superficialis
anterior deep muscles
- flexor digitorum profundus
- flexor pollicis longus
- pronator quadratus
common flexor origin (CFO)
medial epicondyle of humerus
pronator teres
superficial
Origin: medial epicondyle of humerus (CFO)
Insertion: lateral radius
Action: pronation
flexor carpi radialis
superficial
Origin: medial epicondyle of humerus (CFO)
Insertion: 2nd and 3rd metacarpals
Action: flexion of wrist, abduction of wrist
palmaris longus
superficial
Origin: medial epicondyle of humerus
Insertion: palmar aponeurosis
Action: weak flexion of wrist
palmar aponeurosis
- thickening of palmar fascia
(connective tissue) - continuous with the tendon of palmaris longus
flexor carpi ulnaris
superficial
Origin: medial epicondyle of humerus; olecranon of ulna
Insertion: carpals (pisiform & hook of hamate), 5th metacarpal
Action: flexion of wrist, adduction of wrist
flexor digitorum superficialis
intermediate
Origin: medial epicondyle of humerus anterior surface of radius and ulna
Insertion: 4 tendons split and insert on middle phalanges 2-5
Action: flexion of wrist, flexion of metacarpophalangeal joint 2-5, flexion of proximal interphalangeal joints 2-5
flexor digitorum profundus
Origin: ulna, interosseus membrane
Insertion: distal phalanges 2-5
Action: same as FDS, in addition to flexion of distal interphalangeal joints 2-5
flexor pollicis longus
the thumb
Origin: anterior radius, interosseus membrane
Insertion: distal phalanx of the thumb
Action: flexion of the thumb
pronator quadratus
Origin: distal anterior surface of ulna
Insertion: distal anterior surface of radius
Action: pronation
anterior forearm innervation
median nerve: all anterior forearm muscles expect:
ulnar nerve:
- flexor carpi ulnaris
- medial half of flexor digitorum profundus
flexor retinaculum
fibrous connective tissue band located on the palmar surface of the hand, near the wrist
- holds the tendons of the flexor muscles in place
- forms the roof of the carpal tunnel
carpal tunnel
flexor retinaculum arches over the carpal bones of the wrist to form the carpal tunnel
contains:
- flexor digitorum superficialis & profundus
- flexor pollicis longus
- median nerve
posterior compartment of forearm
superficial
deep
the 6 superficial posterior muscles
- brachioradialis
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digit minimi
- extensor carpi ulnaris
brachioradialis- posterior superficial
Origin: lateral supracondylar ridge of humerus
Insertion: styloid process of radius
Action: flexes forearm at elbow
innervation: radial nerve
extensor carpi radialis longus & brevis
Origin: lateral epicondyle of humerus
Insertion: 2nd & 3rd metacarpals
Action: extension of wrist, abduction
extensor carpi ulnaris
Origin: lateral epicondyle of humerus
Insertion: base of 5th metacarpal
Action: extension of wrist, adduction of wrist
extensor digitorum
Origin: lateral epicondyle of humerus
Insertion: posterior surfaces of phalanges 2-5
Action: extension of wrist, extension of fingers
extensor digit minimi
Origin: lateral epicondyle of humerus
Insertion: middle phalanx of pinky finger (5th digit), posterior surface
Action: extension of wrist, extension of pinky finger