Muscles of the Shoulder, Elbow, Wrist and Hand Flashcards
Deltoid
All fibers: abduct shoulder
Anterior fibers: flex, IR and horizontally adduct the shoulder
Posterior fibers: extend, ER, and horizontally abduct the shoulder
O: lateral 1/3 of clavicle, acromion and spine of scapula
I: deltoid tuberosity
Axillary Nerve
C5, 6
Trapezius
Upper fibers:
- Bilaterally extend head and neck
- Unilaterally: laterally flex to the SAME side, rotate to the OPPOSITE side, elevate and upwardly rotate the scapula
Middle Fibers: adduct and stabilize the scapula
Lower Fibers: depress and upwardly rotate the scapula
O: external occipital protuberance, medial portion of superior nuchal line of the occiput, ligaments niche and SP of C7-T12
I: lateral 1/3 of clavicle, acromion and spine of scapula
Spinal portion of CN XI (accessory) and ventral ramus C2-4
Latissimus Dorsi
Extends, IR and adducts the shoulder
O: inferior angle of scapula, SP of T6-12, ribs 8-12, thoracolumbar aponeurosis and posterior iliac crest
I: Intertuberuclar groove of the humerus
Thoracodorsal Nerve
C6-8
Teres Major
Extends, adducts and IR the shoulder
O: inferior angle and lower 1/3 of lateral border of scapula
I: crest of the lesser tubercle of the humerus
Lower sub scapular nerve
C5-7
Supraspinatus
Abducts the shoulder
Stabilizes the humeral head in the glenoid cavity
O: supraspinatus fossa of the scapula
I: Greater tubercle
Suprascapular Nerve
C5-6
Infraspinatus
ER and abducts the shoulder
Stabilizes the humeral head
O: Infraspinatus fossa
I: greater tubercle
Suprascapular Nerve
C5-6
Teres Minor
ER and adduct the shoulder
Stabilizes the humeral head
O: upper 2/3 of lateral border of scapula
I: greater tubercle
Axillary Nerve
C5-6
Subscapularis
IR shoulder
O: subscapular fossa
I: lesser tubercle
Upper and lower sub scapular nerve
C5-6
Rhomboids
Adduct, elevate and downwardly rotate the scapula
Major O:SP T2-5
Major I: medial border of the scapula between scapula spine and inferior angle
Minor O: SP of C7-T1
Minor I: upper portion of the medial border of the scapula, across from spine of scapula
Dorsal scapular nerve
C4-5
Levator scapula
Bilaterally: extends the neck
Unilaterally: laterally flexes neck and rotates to the same side; elevates and downwardly rotates scapula
O: TP of C1-4
I: medial border of scapula between superior angle and superior portion of spine of scapula
C3,4 and Dorsal scapular nerve
C3-4
Serratus Anterior
With the origin fixed:
Abducts, upwardly rotates and depresses the scapula
Holds medial border of scapula against rib cage
With the scapula fixed: may act to elevate the thorax during forced inhalation
O: external surfaces of ribs 1-9
I: anterior surface of medial border of scapula
Long thoracic nerve
C5-7
Pectoralis Major
All fibers: adduct and IR the shoulder; assist to elevate the thorax during forced inhalation (with the arm fixed)
Upper fibers (clavicular portion): flex and horizontally adduct the shoulder
Lower fibers (sternocostal portion): extend the shoulder
Clavicular portion O: medial half of clavicle, Sternocostal portion O: sternum and cartilage of ribs 1-6
I: crest of greater tubercle
Upper fibers: lateral pectoral nerve C5-7
Lower fibers: lateral and medial pectoral nerve C6-T1
Pectoralis Minor
Scapular depression, protraction and downward rotation
With the scapula fixed, assists to elevate the thorax during forced inhalation
O: ribs 3-5
I: Medial surface of coracoid process of the scapula
Medial pectoral nerve C8-T1
Biceps Brachii
Shoulder flexion
Elbow flexion
Supination
Long head O: supraglenoid tubercle of scapula (tendon passes through the inter tubercular groove of the humerus)
Short head O: coracoid process of scapula
I: Radial tuberosity and aponeurosis of the biceps
Musculocutaneous nerve (C5, 6)
Triceps
All: extend the elbow (humeroulnar joint)
Long head: extends and adducts the shoulder
Long head O: infraglenoid tubercle
Lateral head O: posterior surface of proximal half of the humerus
Medial head O: posterior surface of distal half of the humerus
I: olecranon process of the ulna
Radial nerve C6-T1
Coracobrachialis
“armpit muscle”; deep to the pec major and ant deltoid and lies anterior to the axillary artery and brachial plexus
secondary flexor and adductor of the shoulder
O: coracoid process of the scapula
I: medial surface of mid humeral shaft
Musculocutaneous nerve C6-7
Brachialis
strong elbow flexor
lies deep to biceps brachii
O: distal half of anterior surface of humerus
I: ulnar tuberosity and coronoid process
Musculocutaneous C5-7
Brachioradialis
Flexes the elbow
Assists to pronate and supinate the forearm when these movements are resisted
O: proximal 2/3 of the lateral supracondylar ridge of the humerus
I: styloid process of the radius
Radial nerve C5-6
Extensor carpi radialis longus and brevis
Extend and abduct the wrist
Assist to flex the elbow
Longus
O: distal 1/3 of lateral supracondylar ridge of humerus
I: base of 2nd metacarpal
Radial nerve C6-7
Brevis
O: common extensor tendon from the lateral epicondyle of humerus
I: base of 3rd metacarpal
Posterior interposes off radial nerve C7-8
Extensor carpi ulnaris
Extends and adducts the wrist
O: common extensor tendon from the lateral epicondyle of the humerus
I: base of 5th metacarpal
Posterior interosseus off the Radial nerve C7-8
Extensor digitorum
extends fingers 2-5 (MCP and IP joints)
Assists to extend the wrist
O: common extensor tendon from the lateral epicondyle of the humerus
I: bases of middle and distal phalanges of fingers 2-5
Posterior interosseus (radial) C7-8
Anconeus
weak elbow extensor
O: lateral epicondyle of humerus
I: olecranon process and posterior, proximal surface of ulna
Radial nerve C7-T1
Extensor Indicis
Extends and adducts the 2nd finger
May assist with wrist extension
O: posterior surface of distal shaft of ulna and interosseous membrane
I: tendon of the extensor digitorum at the level of the 2nd metacarpal
Posterior interossei (radial) C7-8
Flexor carpi radialis
Flexes and abducts the wrist
May help to flex the elbow
O: common flexor tendon from medial epicondyle
I: bases of 2nd and 3rd metacarpals
Median nerve C6-7
Palmaris Longus
Tense the palmar fascia
Flex the wrist
May assist to flex the elbow
O: Common flexor tendon from medial epicondyle
I: Flexor retinaculum and palmar aponeurosis
Median nerve C6-T1
Flexor carpi ulnaris
Flex and adduct the wrist
Assist to flex the elbow
Humeral head O: common flexor tendon from medial epicondyle
Ulnar head O: posterior surface of proximal 2/3 ulna
I: pisiform, hook of the hamate and base of 5th metacarpal
Ulnar nerve C7-C8
Flexor digitorum superficialis
Flexes fingers 2-5 (MCP and proximal IPs)
Flexes the wrist
O: common flexor tendon, ulnar collateral ligament, coronoid process of ulna, interosseous membrane and proximal shaft of radius
I: sides of middle phaanages of fingers 2-5
Median nerve C7-T1
Flexor digitorum profundis
Flexes fingers 2-5 (MCP and DIPs)
Assists to flex the wrist
O: anterior and medial surfaces of proximal 3/4 of ulna
I: bases of distal phalanges, palmar surface of fingers 2-5
Anterior interosseus (median) C8-T1
Pronator teres
Pronates the forearm
Assists to flex the elbow
O: common flexor tendon from medial epicondyle and coronoid process of the ulna
I: middle of lateral surface of the radius
Median nerve C6-7
Pronator Quadratus
Pronates the forearm
O: medial, anterior surface of distal ulna
I: lateral, anterior surface of distal radius
Anterior interosseous -Median nerve C7-T1
Supinator
Supinates the forearm
O: lateral epicondyle, radial collateral ligament, anular ligament and supinator crest of the ulna
I: anterior, lateral surface of proximal 1/3 of radial shaft
Radial nerve C5-6
Abductor pollicis longus
Abducts and extends the thumb
Radially deviates the wrist
O: posterior surface of radius and ulna and interosseous membrane
I: base of 1st metacarpal
Posterior interosseous (Radial) nerve C7-8
Extensor Pollicis Longus and brevis
Extends the thumb (CMC, MCP and IP)
Abducts the wrist
Longus
O: posterior surface of ulna and interosseous membrane
I: base of distal phalanx of thumb
Brevis:
O: posterior surface of radius and interosseous membrane
I: base of proximal phalanx of thumb
Posterior interosseous (radial) nerve C7-8
Flexor pollicis longus
Flex the thumb (CMC, MCP, IP)
Assists to flex the wrist
O: anterior surface of radius and interosseous membrane
I: base of distal phalanx of thumb
Anterior interosseous (median) nerve C8-T1
Abductor pollicis brevis
abducts the thumb (CMC and MCP)
Assists in opposition
O: flexor retinaculum, trapezium and scaphoid tubercles
I: base of proximal phalanx of thumb
Median nerve C8-T1
Flexor pollicis brevis
Flexes the thumb (CMC and MCP)
Assists in opposition
Superficial head O: flexor retinaculum
Deep head O: trapezium, trapezoid and capitate
I: base of proximal phalanx of thumb
Superficial head: median N (C8-T1)
Deep head: ulnar N C8-T1
Opponens pollicis
Opposition of the thumb at the CMC
O: flexor retinaculum and tubercle of the trapezium
I: entire length of 1st metacarpal bone, radial surface
Median nerve (C8-T1)
Adductor pollicis
Adducts the thumb (CMC and MCP)
Assists to flex the thumb (MCP)
O: capitate, 2nd and 3rd metacarpals
I: base of proximal phalanx of thumb
Ulnar nerve C8-T1
Abductor digiti minimi
abduct 5th digit (MCP
Assists in opposition of the 5th finger
O: pisiform and tendon of FCU
I: base of proximal phalanx of 5th finger, ulnar surface
Ulnar nerve C8-T1
Flexor digiti minimi brevis
Flexes the 5th finger (MCP)
Assists in opposition of the 5th finger
O: hook of the hamate and flexor retinaculum
I: base of proximal phalanx of 5th finger, palmar surface
Ulnar nerve C8-T1
Opponens digiti minimi
Opposition of 5th finger at the CMC
O: hook of hamate and flexor retinaculum
I: shaft of 5th metacarpal, ulnar surface
Ulnar nerve C8-T1
Lumbricals of the hand
Flexes fingers 2-5 at MCPs
Extension of proximal and distal IPs
O: surfaces of the FDP tendons
1st- from radial side of index finger (unipennate)
2nd- from radial side of middle finger (unipennate)
3rd- from contiguous sides of middle and ring fingers (bipennate)
4th- from contiguous sides of ring and little fingers (bipennate)
I: extensor aponeurosis on dorsal surface of phalanges (passes on the radial side of each digit and inserts into the distal wing of the extensor expansion)
2nd & 3rd fingers: median N C6-T1
4th & 5th fingers: ulnar N C8-T1
Palmar interossei (unipennate)
Adducts fingers 2, 4, 5 towards the 3rd finger
Assists to flex the thumb, 2nd, 4th and 5th fingers at the MCPs
Asssists to extend the thumb, 2nd, 4th and 5th fingers at the IPs
O: base of 1st, 2nd, 4th and 5th metacarpals
I: base of the proximal phalanx of the related finger and the extensor aponeurosis
Ulnar nerve C8-T1
Dorsal interossei (bipennate)
Abducts the 2nd, 3rd and 4th fingers at the MCPs
Assists to flex 2nd, 3rd and 4th fingers at the MCP
Assists to extend the 2nd, 3rd and 4th fingers at the IP
O: adjacent sides of all metacarpals
I: base of the proximal phalanx of the 2nd, 3rd and 4th fingers and the extensor aponeurosis
Ulnar nerve C8-T1
