Forearm Muscles Flashcards
Origin and insertion of Pronator Teres
Two heads
O- medial head- coronoid process
Humeral head- medial epicondyle
I- middle convex of lateral surface of radius (distal to supinator insertion)
Name the flexor/pronation muscles
- superficial
- intermediate
- deep
Superficial- Pronator Teres, Flexor Carpi Radialis, Palmaris longus, Flexor Carpi ulnaris
Intermediate- Flexor digitorum superficialis
Deep - Flexor digitorum Profundus, Flexor pollicis longus, Pronator Quadratus
Innervation of Pronator Teres
Median nerve
Action of Pronator Teres
Probated and flexes forearm at elbow
Origin and insertion of Flexor Carpi Radialis
O- medial epicondyle of humerus
I- base of 2nd metacarpal
Innervation of FCR
Median nerve
Action of FCR
Flexes and abducts hand at wrist
Origin and insertion of Palmaris longus
O- medial epicondyle of humerus
I- distal half of flexor-retina cultus and apex of palmar aponeurosis
Innervation of Palmaris longus
Median nerve
Action of Palmaris longus
Flexes hand at wrist and tenses palmar aponeurosis
Origin and insertion of flexor Carpi ulnaris (humeral and ulnar head)
O- humeral head- medial epicondyle of humerus
Ulnar head- olecranon and posterior border of ulna
I- pisiform, hook of hamate, 5th metacarpal
Innervation of FCU
Ulnar nerve
Action of FCU
Flexes and adducts hand at wrist
Origin and insertion of flexor Carpi superficialis
Humeral head and radial head
O- humeral head- medical epicondyle and coronoid process
Radial head- superior half of anterior border
I- shafts of middle phalanges (medial digits)
Innervation of FDS
Median nerve
Action of FDS
Flexes middle phalanges at proximal interphalangeal joints of middle 4 digits; acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints
Origin and insertion of Flexor Digitorum Profundus
O- proximal 3/4 of medial and anterior ulna and interosseous membrane
I- medial part- bases of distal phalanges of 4-5th digits
Lateral part - bases of distal phalanges at 2-3rd digits
Innervation of FDP
Medial and lateral part
Lateral part- median nerve
Medial part- ulnar nerve
Action of FDP
Flexes distal phalanges of 2-5th distal interphalangeal joints
Origin and insertion of flexor pollicis longus
O- anterior surface if radius and interosseous membrane
I- base of distal phalanx of thumb
Innervation of FPL
Median nerve
Action of FPL
Flexes phalanges of 1st digit
Origin and insertion of Pronator Quadratus
O- distal quarter of anterior surface of ulna
I- distal quarter of anterior surface of radius
Numeration of Pronator Quadratus
Median nerve
Action of Pronator Quadratus
Pronator the arm
Deep fibers bind ulna and radius together
Name the extensor/supinator muscles
Superficial deep and outcropping
Superficial- brachioradialis, extensor Carpi Radialis longus, extensor Carpi Radialis brevis , extensor digitorum, extensor digitiminimi, extensor Carpi ulnaris.
Deep- supinator, extensor indices
Outcropping (deep layer) - abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus, = snuff box
Origin and insertion of brachioradialis
O- proximal 2/3 of lateral supra-epicondylar ridge
I- lateral surface/distal end of radius-proximal to styloid process
Innervation of brachioradialis
Radial nerve
Action of brachioradialis
Relatively weak flexion of forearm (maximal when forearm is in mid probated position)
Origin and insertion of extensor Carpi Radialis longus
O- lateral supra-epicondylar ridge of humerus
I- dorsal base of 2nd metacarpal
Innervation if ECRL
Radial nerve
Action of ECRL
Extends and abducts hand at the wrist joint
Active during fist clenching
Origin and insertion of Extensor Carpi Radialis Brevis
O- Lateral epicondyle of humerus
I- Dorsal aspect of base of 3rd metacarpal
Innervation of ECRB
Radial nerve
Action of ECRB
Extends and abducts hand (works with ECRL)
Origin and insertion of extensor digitorum
O- lateral epicondyle of humerus
I- Extensor expansions of medial 4 digits
Innervation of ED
Radial nerve
Action of ED
Extends medial 4 digits primarily at metacarpophalangeal joints, secondarily at interphalangeal joints
Origin and insertion of Extensir Digiti Minimi
O- lateral epicondyle of humerus
I- extensor expansions of 5th digit
Innervation of EDM
Radial nerve
Action of EDM
Extends 5th digit primarily at metacarpophalangeal joint, secondarily at Interphalangeal joint
Origin and insertion of Extensor Carpi ulnaris
O- lateral epicondyle of humerus, posterior border of ulna.
I- dorsal aspect of base of 5th metacarpal
Innervation of ECU
Radial nerve
Action of Extensor Carpi Ulnaris
Extends and adducts hand at wrist joint
Also active during fist clenching
Origin and insertion of Supinator muscle
O- lateral epicondyle of humerus, radial collateral and angular ligaments. Crest of ulna
I- lateral, posterior and anterior surface of proximal 3rd of radius
Innervation of supinator
Radial nerve
Action of supinator
Supinate forearm
Origin and insertion of extensor indices
O- posterior surface of distal 3rd of ulna and interosseous membrane
I- Extensor expansion of 2nd digit
Innervation of extensor indices
Radial nerve
Action of extensor indices
Extends 2nd digit
Enables independent expansion
Helps extend hand at wrist
Origin and insertion of abductor pollicis longus
O- posterior surface of proximal halves of ulna radius and interosseous membrane
I- base of 1st metacarpal
Innervation of APL
Radial nerve
Action of APL
Abducts thumb and extends it at carpometacarpal joint
Origin and insertion of extensor pollicis brevis
O- posterior surface of distal 3rd of ulna and interosseous membrane
I- dorsal aspect of base of proximal phalanx of thumb
Innervation of EPB
Radial nerve
Action of EPB
Extends proximal phalanxes of thumb at metacarpophalangeal joint, extends carpometacarpal joint
Origin and insertion of extensor pollicis longus
O- posterior surface of middle 3rd of ulna and interosseous membrane
I- dorsal aspect of base of distal phalanx of thumb
Innervation of EPL
Radial nerve
Action EPL
Extends distal phalanx of thumb at interphalangeal , metacarpophalangeal joint; extends carpometacarpal joint
