Pectoralis Major
Origin: -anterior border of medial have of clavicle (& head)
- anterior surface of sternum
-superior six costal cartilages
insertion: humerus
innervation: C5-T1
actions: -flex humerus
- adduct humerus
- medially rotate humerus
- draw scapula anterior and inferior
Pectoralis Minor
Origin: 3rd - 5th ribs
insertion: coracoid process of scapula
innervation: medial pectoral nerve (C8, T1)
action: -stabilize scapula by drawing inferiorly and anteriorly against thoracic wall
-protract/abduct scapula
-raise ribs in inspiration
Serratus Anterior
origin: outer surface ribs 1-8
insertion: costal aspect of medial margin of scapula
innervation: long thoracic nerve (from roots of brachial plexus C5-C7)
actions: -protract/abduct and stabilize scapula
-assist in upward rotation of scapula
Deltoid
origin: -anterior lateral third clavicle
-spine of scapula
insertion: deltoid tuberosity of humerus
innervation: axillary n.
action: -clavicular part: flexion and medially rotate arm
-acromial part: abducts arm beyond initial 15 degrees done by supraspinatus m.
-spinus part: extends and laterally rotates arm
Trapezius
origin: occipital protuberance and C7-T12 spinous processes
insertion: clavicle, acromion process, and scapula
innervation: accessory n.(CN XI), C3-C4
action: - retraction/adduction of scapula
-rotate scapula
-elevate scapula
-lower fibers- depress scapula
Rhomboid Major
origin: spinous processes of T2-T5
insertion: medial border of scapula
innervation: dorsal scapular n (C4-C5)
action: -retract/adduct scapula
-rotate scapula to depress glenoid cavity
-fix scapula to thoracic wall
Rhomboid Minor
origin: spinous processes of C7-T1
insertion: medial border of scapula
innervation: dorsal scapular n (C4-C5)
actions: -retract/adduct and rotate scapula
-fix scapula to thoracic wall
Teres Major
origin: posterior aspect of inferior angle of scapula
insertion: humerus
innervation: lower subscapular n. (C5-C6)
actions: -adduct humerus
-internal/medial rotation of humerus
-extend humerus from flexed position
-protract/abduct scapula
-depress shoulder
Teres Minor
origin: lateral border of scapula
insertion: greater tubercle of humerus
innervation: axillary nerve CN XI
actions: -laterally rotate arm
-stabilize humerus
Latissimus Dorsi
origin: T7-L5 spinous processes and iliac crest
insertion: humerus
innervation: thoracodorsal n (C6-C8)
action: -extend, adduct, and medially rotate humerus
-move body toward arms during climbing
Levator Scapulae
origin: C1-C4 transverse processes
insertion: scapula
innervation: C3-C5
action: elevate scapula
Rotator Cuff Muscles
supraspinatus
infraspinatus
teres minor
subscapularis
(Tendons of S.I.T.S)
Supraspinatus
origin: scapula
insertion: superior aspect of greater tubercle of humerus
innervation: suprascapular n. (C4-C6)
action: initiates abduction of arm (first 15 degrees)
Infraspinatus
origin: scapula
insertion: greater tubercle of humerus
innervation: suprascapular n (C4-C6)
action: -lateral rotation of arm
-stabilize humerus
Subscapularis
origin: subscapular fossa of scapula
insertion: lesser tubercle of humerus
innervation: upper and lower subscapular n (C5-C7)
action: -medially rotates arm
-adduct arm
-help hold humeral head in glenoid cavity
shoulder abduction muscles
supraspinatus (inital 15 degrees)
lateral part of deltoid (30-120 degrees)
shoulder adduction muscles
pec major
lat dorsi
coracobrachialis
teres major
anterior and posterior parts of deltoid
shoulder flexion muscles
anterior part of deltoid
coracobrachialis
long head of biceps brachii
shoulder extension muscles
posterior part of deltoid
lat dorsi
teres major
long head of triceps
shoulder medial rotation muscles
lat dorsi
subrascapularis
teres major
pec major
anterior part of deltoid
shoulder lateral rotation muscles
infraspinatus
teres minor
posterior part of deltoid
Shoulder elevation/depression
at SC joint with vertical gliding of scapula
Shoulder prime elevators
cervical portion of trapezius
levator scapula
rhomboid major and minor
shoulder depressors
pec minor
subclavius
thoracic portion of trapezius
shoulder protraction/retraction
at SC joint with horizontal gliding of scapula
shoulder protraction/abduction
pec minor
serratus anterior
shoulder retraction/adduction
rhomboid major and minor
trapezius
shoulder rotation
at AC joint and Sc joint
shoulder superior rotators
trapezius
serratus anterior
shoulder inferior rotators
pec mino
rhomboid major and minor
order of muscles involved în raising arms above head
supraspinatus
deltoid
serratus anterior
3 flexors of arm muscles
biceps brachii
brachialis
coracobrachialis
1 extensor of arm muscles
triceps brachii
Forearm flexors are _____ groups, forearm extensors are ______
anterior; posterior
Forearm flexion/extension
through trochlea
forearm flexors
biceps brachii (acts on radius)
brachialis (acts on ulna)
brachioradialis
forearm extensors
triceps
anconeus
forearm pronation/supination
through capitulum of humerus
forearm pronators
pronator teres (long and short head)
pronator quadratus
forearm supinators
supinator m.
biceps brachii n.
biceps brachii
long head tendon sits in bicipital groove
origin: -short head: coracoid process of scapula
-long head: supraglenoid tubercle of scapula
insertion: radial tuberosity
innervation: musculocutaneous n. (C5-C6)
action: -flex arm
-flex forearm
-supinate forearm
bracialis
origin: distal ½ of anterior surface of humerus
insertion: coronoid process of ulna and tuberosity of ulna
innervation: musculocutaneous n (C5-C6)
action: flex forearm at elbow
coracobrachialis
origin: coracoid process of scapula
insertion:medial aspect of humeral shaft (humerus)
innervation: musculocutaneous n (C5-C7)
action: flex and adduct arm
triceps brachii
origin: -long head: scapula
-lateral head: posterior humerus
-medial head: posterior humerus
insertion: posterior olecranon process of ulna
innervation: radial nerve (C6-C8)
action: -extend forearm at elbow
-long head: extend and adduct arm
anconeus
origin: posterior lateral epicondyle of humerus
insertion: lateral surface of olecranon and superior part of posterior surface of ulna
innervation: radial nerve (C7-T1)
action: -assists triceps in extending forearm
-stabilizes elbow joint
-abducts ulna during pronation
flexion/extension at wrist
through radoiocarpal and ulnocarpal joints
wrist prime flexors
flexor carpi radialis
flexor carpi ulnaris
palmaris longus
flexor digitorum superficialis
flexor digitorum profundus
wrist prime extensors
extensor carpi radialis longus
extensor carpi radialis brevis
extensor digitorum
palmaris longus
origin: medial epicondyle of humerus
insertion: flexor retinaculum and palmar aponeurosis
innervation: median nerve
action: flex wrist (hand at wrist joint)
flexor carpi ulnaris
origin: humeral head (from medial epicondyle of humerus), ulnar head (from medial aspect of olecranon process and posterior border of ulna)
insertion: pisiform bone, hook of hamate, base of 5th metacarpal
innervation: ulnar nerve
action: flex and adduct hand at wrist joint
Pronator teres
origin: humeral head (from medial epicondyle), ulnar head (from medial border of coronoid process of ulna)
insertion: lateral aspect of shaft of radius
innervation: median nerve
action: pronation and flexion of forearm
Flexor carpi radialis
origin: from medial epicondyle of humerus
insertion: bases of 2nd and 3rd metacarpals
innervation: median nerve
action: flex and abduct hand at wrist joint
flexor digitorum superficialis
origin: humeroulnar head from medial epicondyle of humerus and medial border of coronoid process of ulna, radial head from oblique line on anterior surface of shaft of radius
insertion: base of middle phalanx of 2-5 fingers
innervation: median nerve
action: flex middle phalanx of fingers and assist in flexing proximal phalanx at MCP joint
Flexor digitorum profundus
origin: anteromedial surface of shaft of ulna
insertion: distal phalanges of medial four fingers
innervation: medial half- ulnar nerve; lateral half- median nerve
action: flexes distal phalanx of fingers; assists in flexion of wrist
Flexus pollicis longus
origin: anterior surface of shaft of radius
insertion: distal phalanx of thumb
innervation: median nerve
action: flex distal phalanx of thumb
pronator quadratus
origin: anterior surface of ulna
insertion: anterior surface of radius
innervation: median nerve
action: pronate forearm
muscles that extend medial 4 digits
extensor digitorum
extensor indicis
extensor digiti minimi
muscles that extend or abduct thumb
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus
brachioradialis
origin: proximal lateral supra-epicondylar ridge
insertion: styloid process (distal end) of radius
innervation: radial nerve
action: flex forearm
extensor carpi radialis longus
origin: lateral supra-epicondylar ridge of humerus
insertion: base of 2nd metacarpal
innervation: radial nerve
action: extend and abduct wrist
extensor carpi radialis brevis
origin: lateral epicondyle of humerus
insertion: base of 3rd metacarpal
innervation: radial nerve
action: extend and abduct wrist
extensor carpi ulnaris
origin: lateral epicondyle of humerus and posterior border of ulna
insertion: base of 5th metacarpal
innervation: radial nerve
action: extend and adduct wrist
Extensor digitorum
origin: lateral epicondyle of humerus
insertion: extensor expansion medial 4 fingers
innervation: radial nerve
action:extend medial 4 fingers at MCP joints and IP joints
extensor digiti minimi
origin: lateral epicondyle of humerus
insertion: extensor expansion of 5th finger
innervation: radial nerve
action: extend 5th finger
extensor pollicis brevis
origin: distal 1/3 of radius
insertion: base of proximal phalanx of thumb
innervation: radial nerve
action: extend thumb at MCP joint, extend carpometacarpal joint
extensor pollicis longus
origin: middle 1/3 ulna and interosseous membrane
insertion: base of distal phalanx of thumb
innervation: radial nerve
action: extend thumb at IP joint, extend MCP and carpometacarpal joint
abductor pollicis longus
origin: posterior surface of ulna and middle aspect of radius
insertion: base of 1st metacarpal
innervation: radial nerve
action: abducts thumb and extends it at carpometacarpal joint
supinator
origin: lateral epicondyle of humerus and crest of ulna
insertion: upper 1/3 of radius
innervation: radial nerve
action: -supinate forearm
-rotate radius to turn palm anteriorly or superiorly (if elbow is flexed)
extensor indicis
origin: posterior surface of ulna
insertion: extensor expansion of index finger
innervation: radial nerve
action: -extend index finger
-help extend hand at wrist
Short intrinsic hand muscles
lumbrical
dorsal interossei
palmar interossei
Lumbricals I & II unipennate actions
action: flex the MCP joint and extend IP joints of 2 and 3
lumbricals III& IV bipennate actions
action: flex MCP joint and extend IP joints of 4 and 5
Dorsal Interossei (bipennate)
origin: adjacent sides of metacarpal
insertion: base of proximal phalanges; extensor expansions of 2-4 fingers
action: abduct 2-4 fingers from axial line, act with lumbricals in flexing MCP joints and extending IP joints
Palmar interossei (unipennate)
origin: palmar side of 2nd, 4th, and 5th metacarpals
insertion: base of proximal phalanges, extensor expansions of 2nd, 4th, and 5th fingers
innervation: ulnar nerve
action: adduct 2nd, 4th, and 5th fingers toward axial line, assist lumbricals in flexing MCP joint and extending IP joints