Upper Extremity Muscles Flashcards
Supraspinatus
O: supraspinous fossa of the scapula
I: greater tubercle of the humerus
A: assistance in arm abduction, stabilization of the humerus
N: suprascapular nerve
Infraspinatus
O: infraspinous fossa of the scapula
I: greater tubercle of the humerus
A: ER of the arm, stabilization of the humerus
N: suprascapular nerve
Teres minor
O: lateral border of the scapula
I: greater tubercle of the humerus (inferior facet)
A: ER of the arm, stabilization of the humerus
N: axillary nerve
Subscapularis
O: subscapular fossa
I: lesser tubercle of the humerus
A: IR of the arm, stabilization of the humerus
N: upper and lower subscapular nerves
Teres major
O: inferior angle and lower part of the lateral border of the scapula
I: intertubercular sulcus (medial lip) of the humberus
A: adduction and medial rotation of the humerus
N: lower subscapular nerve
Serratus anterior
O: lateral parts of the 1st to 8th ribs
I: medial border of the scapula
A: protraction and rotation of the scapula
N: long thoracic nerve
Levator scapulae
O: transverse process of the atlas and axis, posterior tubercles C3 and C4
I: posterior surface of the medial scapular border (from the superior angle to the root of the spine of the scapula)
A: elevation of the scapula
N: anterior rami of the nerves C3 and C4, dorsal scapular nerve (branch of the C5)
Rhomboid major
O: spinous processes of the T2-5 vertebrae
I: inserts onto the medial border of the scapula
A: retracts scapula, stabilizes scapula against thoracic wall
N: dorsal scapular nerve
Trapezius
O: superior nuchal line, external occipital protruberance, nuchal ligament, spinous processes of C7-T12 vertebrae
I: lateral third of the clavicle, acromion and spine of the scapula
A: elevation, depression, and retraction of the scapula
N: spinal accessory nerve, C3 and C4 spinal nerves
4 rotator cuff muscles
supraspinatus
infraspinatus
teres minor
subscapularis
Pectoralis major
O: medial half of the clavicle (clavicular head), anterior surface of the sternum, 1st to 6th costal cartilages, aponeurosis of external oblique muscle (sternocosotal head)
I: crest of greater tubercle of humerus
A: adduction and IR of humerus
N: lateral nad medial pectoral nerves
Pectoralis minor
O: anterior surface of the 3rd, 4th, and 5th ribs and the fascia overlying the intercostal spaces
I: medial border and superior surface of the coracoid process of the scapula
A: protraction of the scapula, pulls the coracoid process anteriorly and inferiorly, accessory muscle in respiratory
N: medial pectoral nerve
Deltoid
O: lateral third of the clavicle, acromion, and spine of scapula
I: deltoid tuberosity of the humerus
A: abduction and stabilization of the shoulder joint
N: axillary nerve
Latissimus dorsi
O: spinous processes of T5-L5 and sacrum, iliac crest, X-XII ribs
I: intertubercular groove of the humerus
A: contracting insertion > origin = adduction, extension, IR of arm.
Contracting origin > insertion = rotation of the trunk
N: thoracodorsal nerve (C6-C8)
Brachialis
O: distal half of the anterior side of the humerus and intermuscular septa
I: coronoid process and ulnar tuberosity
A: elbow flex
N: musculocutaneous and radial nerves
Biceps brachii
O: long head - supraglenoid tubercle of the scapula.
Short head - apex of the coracoid process of the scapula
I: radial tuberosity of the radius
A: elbow flex, supinate, accessory shoulder flex at GH jt
N: musculocutaneous nerve
coracobrachialis
O: coracoid process of the scapula
I: anteromedial surface of the humerus
A: adduction and flexion of the arm
N: musculocutaneous nerve
Triceps brachii
O: long head - infragenoid tubercle of the scapula
Medial head - posterior surface of the humerus
Lateral head - posterior surface of the humerus
I: olecranon
A: elbow ext
N: radial nerve
Pronator teres
O: medial epicondyle of the humerus (humeral head), coronoid process of the ulna (ulnar head)
I: lateral side of the radius
A: pronation of forearm, flexion of elbow
N: median nerve
Flexor carpi radialis
O: medial epicondyle of the humerus (common flexor tendon)
I: bases of 2nd metacarpal bone
A: flexion and abduction of the hand at the wrist joint
N: median nerve
Palmaris longus
O: medial epicondyle of the humerus (common flexor tendon)
I: flexor retinaculum and palmar aponeurosis
A: flexion of the hand at the wrist joint
N: median nerve
Flexor carpi ulnaris
O: humeral head (medial epicondyle of the humerus), ulnar head (olecranon and posterior border of the ulna)
I: pisiform bone, hook of hamate bone, base of the 5th metacarpal bone
A: flexion and adduction of the hand at the wrist
N: ulnar nerve
Flexor digitorum superficialis
O: medial epicondyle of the humerus and coronoid process of the ulna (humero-ulnar head) and superior half of anterior border (ulnar head).
I: shafts of middle phalanges of medial 4 digits
A: flexion of middle phalanges at proximal interphalangeal joints and flexion of the proximal phalanges at the MCP jts of the middle 4 digits
N: median nerve
Pronator quadratus
O: anterior surface of the ulna (distal quarter)
I: anterior surface of the radius (distal quarter)
A: pronation, binding of the radius and ulna
N: anterior interosseous nerve
Flexor pollicis longus
O: anterior surface of the radius and interosseous membrane
I: base of the distal phalanx of the thumb
A: flexion of the phalanges of the thumb
N: anterior interosseous nerve
Flexor digitorum profundus
O: proximal parts of the anterior and lateral surfaces of the ulna and interosseous membrane
I: bases of the phalanges of the 4th and 5th digits (medial part), bases of the phalanges of the 2nd and 3rd digits (lateral part)
A: flexion of the distal phalanges at the interphalangeal joints of the 4th and 5th digits (medial part) and of the 2nd and 3rd digits (lateral part)
N: ulnar nerve (medial part), anterior interosseous nerve (lateral part).
Supinator
O: lateral epicondyle of the humerus, crest of the ulna, supinator fossa, radial collateral and anular ligaments
I: surface of the proximal third of the radial shaft
A: forearm supination
N: deep branch of the radial nerve
Extensor digitorum
O: lateral epicondyle of the humerus
I: posterior surfaces of the middle and distal phalanges (2nd-5th)
A: extension of the index, middle, ring and little fingers
N: posterior interosseus nerve (branch of the radial nerve)
Extensor carpi ulnaris
O: lateral epicondyle of the humerus, posterior border of the ulna
I: medial side of the base of the metacarpal V
A: extension and adduction of the wrist
N: posterior interosseus nerve (branch of the radial nerve)
Extensor carpi radialis longus
O: lateral supra epicondylar bridge of humerus
I: base of the 2nd metacarpal
A: extension and abduction of the hand at the wrist joint
N: radial nerve
Extensor carpi radialis brevis
O: lateral epicondyle of humerus
I: base of the 3rd metacarpal
A: extension and abduction of the hand at the wrist jt
N: deep branch of radial nerve
Extensor indicis proprius
O: posterior side of the distal third of the ulnar shaft, interosseous membrane
I: external expansion of the 2nd digit
A: extension of the 2nd digit
N: posterior interosseous nerve
Extensor digiti minimi
O: lateral epicondyle of the humerus
I: dorsal aponeurosis of the little finger
A: extension of the little finger
N: posterior interosseus nerve (branch of the raidal nerve)
Brachioradialis
O: proximal two-thirds of the supra-epicondylar ridge of the humerus
I: lateral surface of the distal end of the radius
A: forearm flexion, especially during mid-pronation
N: radial nerve
Thenar eminence 3 muscles:
flexor pollicis brevis
abductor pollicis brevis
opponens pollicis
Hypothenar eminence 3 muscles:
flexor digiti minimi brevis
abductor digiti minimi brevis
opponens digiti minimi
Interossei: made up of ___ dorsal (_____) and ___ palmar inerossei (_____).
- 4 - unipennate
- 3 - bipennate
Lumbricals
O: tendons of the flexor digitorum profundus
I: lateral expansions of the 2nd to 5th digits
A: flexion of the metacarpophalangeal jts and extension of the interphalangeal joints of the 2nd-4th digits
N: median nerve (1st and 2nd lumbricals), deep branch of ulnar nerve (3rd and 4th lumbricals)
Rhomboid minor
O: nuchal ligament, spinous processes of C7 and T1 vertebrae
I: medial end of the scapular spine
A: retraction and fixation of the scapula on the thoracic wall
N: dorsal scapular nerve
Flexor pollicis brevis
O: flexor retinaculum and tubercles of trapezium and scaphoid bones
I: base of the proximal phalanx of the thumb
A: thumb flexion (bending)
N: recurrent branch of the median nerve (superficial head) and deep branch of ulnar head (deep head)
abductor pollicis brevis
O: flexor retinaculum and tubercles of trapezium and scaphoid bones
I: base of the proximal phalanx of the thumb
A: recurrent branch of the median nerve
N: thumb abduction (moving away from the hand)
opponens pollicis
O: flexor retinaculum and tubercle of trapezium and scaphoid bones
I: first metacarpal bone
A: thumb flexion, abduction, and medial rotation resulting in a combined movement called opposition
N: recurrent branch of the median nerve
flexor digiti minimi brevis
O: hook of hamate and flexor retinaculum
I: base of the proximal phalanx of the 5th digit
A: flexion of the proximal phalanx of the 5th digit
N: deep branch of ulnar nerve
abductor digiti minimi brevis
O: pisiform
I: base of proximal phalanx of 5th digit
A: abduction of the 5th digit and flexion assistance of the proximal phalanx
N: deep branch of ulnar nerve
opponens digiti minimi
O: hook of hamate and flexor retinaculum
I: medial border of 5th metacarpal
A: opposition of the 5th digit
N: deep branch of ulnar nerve
Dorsal interossei
O: sides of 2 adjacent metacorpals
I: bases of the proximal phalanges via the extensor expansions of the 2nd to 4th digits
A: abduction of the 2nd to 4th digits, assisting the lumbricals in extension
N: deep branch of ulnar nerve
Palmar interossei
O: palmar surfaces of the 2nd, 4th, 5th metacarpals
I: bases of the proximal phalanges via the extensor expansions of the 2nd, 4th, and 5th digits
A: adduction of the 2nd, 4th, and 5th digits, assisting the lumbricals in extension
N: deep branch of ulnar nerve
