Upper Extremity Myology Flashcards
Pectoralis major OIN
O: Medial half of clavicle, sternum, costal cartilage 1-6
I: Lateral intertubercular groove humerus
N: Medial/lateral pectoral nerve
Pectoralis major action
Adduct and medially rotate humerus, protract and depress scapula
Clavicular head flexes arm, sternal head extends flexed arm
Pectoralis minor OIN
O: Medial aspect ribs 3-5
I: Coracoid process
N: medial pectoral nerve
Pectoralis minor action
Stabilize scapula by protracting and depressing it against thoracic wall
Subclavius OIN
O: 1st rib and costal cartilage
I: Inferior aspect of clavicle
N: Nerve to the subclavius C5/6
Subclavius action
Positions and depresses clavicle
Serratus anterior OIN
O: Lateral surface ribs 1-8
I: Anterior surface medial border of scapula
N: Long thoracic nerve
Serratus anterior action
Protracts scapula, rotates glenoid cavity superiorly
What happens when there is paralysis of the serratus anterior
Winging of the scapula
Deltoid OIN
O: lateral 1/3 clavicle, scapular spine, acromion
I: Deltoid tuberosity of humerus
N: Axillary nerve
Deltoid action
Anterior portion: flex/medially rotate humerus
Middle part: Abduct humerus
Posterior part: Extend/laterally rotate humerus
Subscapularis OIN
O: Subscapular fossa
I: Lesser tubercle of humerus
N: Upper/lower subscapular nerve
Subscapularis action
Medially rotate and adduct humerus
Hold humeral head in glenoid cavity
Supraspinatus OIN
O: supraspinous fossa
I: Greater tubercle
N: Suprascapular nerve
Supraspinatus action
Abduct humerus, hold humeral head in place
Infraspinatus OIN
O: Infraspinous fossa
I: Greater tubercle humerus
N: Suprascapular nerve
Teres minor OIN
O: Middle portion of lateral border of scapula
I: Greater tubercle humerus
N: Axillary nerve
Teres minor action
Laterally rotate humerus, hold humeral head in place
Teres major OIN
O: Inferior angle scapula
I: Medial edge of intertubercular groove
N: Lower subscapular nerve
Teres major action
Adduct and medially rotate humerus
What are the rotator cuff muscles
Supraspinatous- most commonly injured
Infraspinatous
Teres minor
Subscapularis
Biceps brachii OIN
O: Long head- supraglenoid tubercle of scapula
Short head- coracoid process
I: Radial tuberosity and antebrachial fascia as bicipital aponeurosis
N: Musculocutaneous nerve
Biceps tendonitis/crepitus
Repetitive movement of the long head of the biceps through the intertubercular groove can cause inflammation and even a crackling sound
Popeye deformity
Separation of long head of biceps from supraglenoid tubercle, muscle balls up in the middle
Coracobrachialis OIN
O: coracoid process
I: Medial aspect of humeral body
N: musculocutaneous nerve
Coracobrachialis action
Flex and adduct humerus
Brachialis OIN
O: Distal half of anterior humerus
I: Ulnar tuberosity and coronoid process
N: Musculocutaneous nerve
Brachialis action
Flexes forearm
Triceps brachii OIN
O: Long head- infraglenoid tubercle Lateral head- posterior humeral body, superior to radial groove Medial head- inferior to radial groove I: Olecranon of ulna N: Radial nerve
Triceps brachii function
Extend forearm, long head resists dislocation of shoulder
Anconeus OIN
O: Lateral humeral epicondyle
I: Lateral aspect of olecranon
N: Radial nerve
Triangular space borders and contents
Teres major, teres minor, long head of triceps
Circumflex scapular artery and vein
Quadrangular space borders and contents
Teres minor/major, Long/lateral heads of triceps
Posterior humeral circumflex artery/vein, axillary nerve
Triangular interval borders and contents
Teres major, long/lateral heads of triceps
Deep brachial artery/vein, radial nerve
Pronator teres OIN
O: Humeral head- medial humeral epicondyle
Ulnar head- coronoid process of ulna
I: Lateral aspect of radius
N: median nerve
Pronator teres action
Pronate and flex forearm
Flexor carpi radialis OIN
O: medial epicondyle
I: Ventral aspect of base of 2nd metacarpal
N: Median nerve
Flexor carpi radialis action
Flex forearm, flex and abduct hand at wrist
Palmaris longus OIN
O: medial epicondyle
I: palmar aponeurosis, flexor retinaculum
N: median nerve
Palmaris longus action
Flex forearm, flex hand and tense palmar aponeurosis
Flexor carpi ulnaris OIN
O: Humeral head- medial epicondyle
Ulnar head- olecranon
I: pisiform, hook of hamate, base of 5th metacarpal
N: Ulnar nerve
Flexor digitorum superficialis OIN
O: medial epicondyle, coronoid, superior half of radius
I: Bifed insertion on intermediate phalanges of 2-5
N: Median nerve
Flexor digitorum superficialis action
Flex forearm, flex hand at wrist, flex proximal/intermediate phalanges of 2-5
Flexor digitorum profundus OIN
O: proximal ulna/interosseous membrane
I: Bases of distal phalanges of 2-5
N: Lateral part- anterior interosseous N from median N
Medial part- ulnar nerve
Flexor digitorum profundus action
Flex hand at wrist, flex all phalanges of 2-5
Flexor pollicus longus OIN
O: Anterior aspect of radius
I: base of distal phalanx of thumb
N: Lateral part- anterior interosseous N from median N
Medial part- ulnar nerve
Flexor pollicus longus action
Flex hand, flex and abduct 1st metacarpal, flex both phalanges of thumb
Pronator quadratus OIN
O: Anterior distal ulna
I: Anterior distal radius
N: anterior interosseous from median N
Pronator quadratus action
Pronate forearm
Brachioradialis OIN
O: lateral humeral supracondylar ridge
I: Lateral distal radius
N: radial nerve
Brachioradialis action
Flex forearm, most force when forearm is midpronated
Extensor carpi radialis longus OIN
O: lateral humeral supracondylar ridge
I: Dorsal aspect of base of 2nd metacarpal
N: radial nerve
Extensor carpi radialis longus action
Extend and abduct hand at wrist
Extensor carpi radialis brevis OIN
O: lateral humeral epicondyle
I: base of 3rd metacarpal
N: Deep radial nerve
Extensor digitorum OIN
O: lateral humeral epicondyle
I: extensor expansion of 2-5
N: posterior interosseous
Extensor digitorum action
Extend hand at wrist, extend all phalanges of 2-5
Extensor digiti minimi OIN
O: lateral humeral epicondyle
I: Extensor expansion of 5
N: posterior interosseous
Extensor digit minimi action
Extend all phalanges of digit 5
Extensor carpi ulnaris OIN
O: Lateral epicondyle
I: Base of 5th metacarpal
N: posterior interosseous
Extensor carpi ulnaris action
Extend/adduct hand at wrist
Elbow tendonitis and lateral epicondylitis
Elbow tendonitis/tennis elbow- repetitive use of superficial extensor muscles of forearm can cause this
Lateral epicondylitis- repeated flexion and extension of the wrist strains periosteum of lateral humeral epicondyle
Supinator OIN
O: Lateral epicondyle and some ligaments
I: Proximal aspect of radial body
N: Deep radial nerve
Supinator action
Supinates forearm
Extensor indicis OIN
O: Posterior aspect of distal ulna
I: Extensor expansion of digit 2
N: posterior interosseous nerve
Extensor indicis action
Extend hand at wrist, extend 2nd digit
Abductor pollicus longus OIN
O: posterior aspect of proximal ulna/radius
I: base of 1st metacarpal
N: posterior interosseous
Abductor pollicus longus action
Abduct hand at wrist, abduct thumb
Extensor pollicis longus OIN
O: posterior ulna
I: base of distal phalanx of thumb
N: posterior interosseous
Extensor pollicis longus action
Abduct hand at wrist, extend 1st metacarpal and all phalanges of thumb
Extensor pollicis brevis OIN
O: posterior radius
I: Base of proximal phalanx of thumb
N: posterior interosseous
Extensor pollicis brevis action
Abduct hand, extend 1st metacarpal and proximal phalanges of thumb
Anatomical snuff box borders and contents
Lateral/anterior: abductor pollicis longus and extensor pollicis brevis
Medial/posterior: extensor pollicis longus
Radial artery, superficial radial nerve
Abductor pollicis brevis OIN
O: Tubercles of scaphoid and trapezium, flexor retinaculum
I: Lateral aspect of base of proximal phalanx of thumb
N: recurrent median N
Opponens pollicis OIN
O: tubercles of scaphoid and trapezium, flexor retinaculum
I: lateral aspect of 1st metacarpal
N: recurrent median N
Opponens pollicis action, and what could cause the action to be lost
Oppose thumb
Even a superficial injury of the palm can damage the recurrent branch of the median nerve and cause loss of ability to opose thumb
Flexor pollicis brevis OIN
O: tubercles of scaphoid and trapezium, flexor retinaculum
I: lateral aspect of base of proximal phalanx of thumb
N: superficial head- recurrent median
Deep head- deep ulnar nerve
Adductor pollicis OIN
O: Capitate, base of 2nd/3rd metacarpal
I: medial aspect of proximal phalanx of thumb
N: deep ulnar nerve
Adductor pollicis action
Adduct thumb
Abductor digiti minimi OIN
O: pisiform
I: medial aspect of base of proximal phalanx 5
N: deep ulnar nerve
Abductor digit minimi action
Abducts 5th digit
Flexor digiti minimi brevis OIN
O: hook of hamate and flexor retinaculum
I: medial aspect of base of proximal phalanx 5
N: deep ulnar nerve
Flexor digiti minimi brevis action
Flex proximal phalanx of 5th digit
Opponens digiti minimi OIN
O: hook of hamate, flexor retinaculum
I: medial aspect of 5th metacarpal
N: deep ulnar nerve
1st and 2nd lumbrical OIN
O: lateral side of lateral two flexor digitorum profundus tendons as unipennate muscles
I: radial aspect of extensor expansion of 2nd/3rd digits
N: Median nerve
1st and 2nd lumbrical action
Flex proximal phalanges 2/3, extend intermediate/distal phalanges of 2/3 by tightening extensor expansion
3rd and 4th lumbrical OIN
O: between medial three flexor digitorum profundus tendons as bipennate muscles
I: radial aspect of extensor expansion of 4th/5th digits
N: deep ulnar nerve
3rd 4th lumbrical action
Flex proximal phalanges 4/5, extend intermediate and distal phalanges 4/5 by tightening extensor expansion
Dorsal interossei 1-4 (DAB) OIN
O: adjacent sides of two metacarpals as bipennate muscle
I: bases of proximal phalanges and extensor expansion of 2-4
N: deep ulnar nerve
Dorsal interossei action
Abduct digits 2-4, flex proximal phalanges, extend intermediate/distal phalanges
Palmar interossei (PAD) OIN
O: palmar aspect of 2nd, 4th, 5th metacarpals
I: bases of proximal phalanges and extensor expansion of 2nd, 4th and 5th digits
N: deep ulnar nerve
Palmar interossei action
Adduct the 2/4/5 digits, flex proximal phalanges and extend intermediate/distal phalanges of 2/4/5
Dorsal interossei action
Abduct digits 2-4, flex proximal phalanges, extend intermediate/distal phalanges
Palmar interossei (PAD) OIN
O: palmar aspect of 2nd, 4th, 5th metacarpals
I: bases of proximal phalanges and extensor expansion of 2nd, 4th and 5th digits
N: deep ulnar nerve
Palmar interossei action
Adduct the 2/4/5 digits, flex proximal phalanges and extend intermediate/distal phalanges of 2/4/5
