Trapezius - Origin
Medial 1/3 superior nuchal line of occipital; external occipital protuberence (inion); ligamentum nuchae; spinous process of C7-T12 and supraspinous ligament
Trapezius - Insertion
Lateral 1/3 of posterior border of clavicle; medial margin of acromion process; superior lip of scapular spine; base of scapular spine
Trapezius - Nerve Innervation
Accessory (CN XI) motor / C3-C4 sensory
Trapezius - Action
Scapular elevation (superior fibers); retraction/adduction (middle fibers); depression (inferior fibers); superior (upward) rotation of the scapula (superior & inferior fibers)
Latissimus Dorsi - Origin
Spinous processes of lower 6 thoracic vertebrae (T7-T12); supraspinous ligament; spinous processes of lumbar & sacral vertabrae through thoracolumbar fascia; external lip of iliac crest (lower 3-4 ribs by fleshy attachments)
Latissimus Dorsi - Insertion
Floor of the intertubercular groove
Latissimus Dorsi - Nerve Innervation
thoracodorsal (C6-C7)
Latissimus Dorsi - Action
Arm extension, hyperextension, adduction and medial rotation. Most powerful action is drawing the arm down from above the head
Levator Scapulae - Origin
Transverse processes of vertebrae C1-C4
Levator Scapulae - Insertion
Posterior surface of medial border of scapula from superior angle to base of spine
Levator Scapulae - Nerve Innervation
Dorsal Scapular (C5); Cervical (C3-C4)
Levator Scapulae - Action
Elevates scapula; tilts glenoid cavity downward by rotating the scapula
Rhomboid Minor - Origin
Spinous processes of C7 & T1
Rhomboid Minor - Insertion
Medial border of scapula from base of spine to inferior angle
Rhomboid Minor - Nerve Innervation
Dorsal scapular (C5)
Rhomboid Minor - Action
Scapular elevation; retraction (adduction); downward rotation, fix scapula to thoracic wall
Rhomboid Major - Origin
Spinous processes of T2-T5; supraspinous ligament
Rhomboid Major - Insertion
Medial border of scapula from base of spine to inferior angle
Rhomboid Major - Nerve Innervation
Dorsal Scapular (C5)
Rhomboid Major - Action
Scapular elevation; retraction (adduction); downward rotation, fix scapula to thoracic wall
Deltoid - origin
lateral third of clavicle
anterior border
lateral border of acromion process
inferior lip of spine to smooth triangular space
deltoid - insertion
deltoid tuberosity of humerus
deltoid - nerve innervation
axillary (C5)
deltoid - action
can act as whole or
anterior: flexor and medial rotator
middle: chief abductor of humerus
posterior: extensor and lateral rotator of humerus
subscapularis - origin
subscapular fossa (medial 2/3)
subscapularis - insertion
lesser tuberosity of humerus
subscapularis - nerve innervation
upper and lower subscapular (C5-C6)
subscapularis - action
medial rotation and adduction of arm
holds head of humerus in glenoid cavity
supraspinatus - origin
medial 2/3 of supraspinous fossa
supraspinatus - insertion
superior facet of greater tuberosity of humerus
supraspinatus - nerve innervation
suprascapular (C5)
supraspinatus - action
arm abduction
holds heads of humerus in glenoid cavity
infraspinatus - origin
medial 2/3 of infraspinous fossa
infraspinatus - insertion
middle facet of greater tuberosity of humerus
infraspinatus - nerve innervation
suprascapular (C5)
infraspinatus - action
external (lateral) rotation of humerus
holds head of humerus in glenoid cavity
teres major - origin
dorsal surface of scapula near inferior angle
teres major - insertion
medial lip of inter tubercular sulcus of humerus (crest of lesser tubercle)
teres major - nerve innervation
lower subscapular (C5,C6)
teres major - action
adduction and internal (medial) rotation of humerus
important stabilizer of proximal end of humerus during adduction
teres minor - origin
upper 2/3 lateral border of scapula
teres minor - insertion
inferior facet of greater tuberosity of humerus
teres minor - nerve innervation
axillary (C5)
teres minor - action
external rotation of humerus
adduction/extension of humerus
holds humerus in glenoid cavity
pectoralis major - origin
anterior surface
medial half of clavicle
costal cartilage of upper 6 ribs
aponeurosis of external oblique muscle
pectoralis major - insertion
lateral lip of intertubercular groove (crest of greater tuberosity of humerus)
pectoralis major - nerve innervation
lateral pectoralis (C6)
medial pectoralis (C7,C8)
pectoralis major - action
adduction and medial rotation of arm
horizontal adduction
flexion (clavicular head)
extension (sternal head)
pulls trunk up with arms stabilized
pectoralis minor - origin
anterior surface and upper margin of ribs 3-5
pectoralis minor - insertion
medial border of coracoid process of scapula
pectoralis minor - nerve innervation
medial pectoral (C8)
pectoralis minor - action
scapular abduction
depresses tip of shoulder joint (downward and forward)
subclavius - origin
costal cartilage of rib 1
subclavius - insertion
inferior surface of clavicle (subclavian groove)
subclavius - nerve innervation
nerve to the subclavius (C5)
subclavius - action
depresses clavicle (lateral end)
assists in scapular depression and abduction
serratus anterior - origin
outer surfaces and superior border of ribs 1-8
midway between angles and costal cartilages (lower 3 digitations interdigitate with origin of external oblique muscles)
serratus anterior - inserition
anterior surface of entire medial border of scapula
serratus anterior - nerve innervation
long thoracic (C6-C7)
serratus anterior - action
protraction and rotation of scapula
fixes scapula for other muscles (anchor)
biceps brachii - origin
long head: supraglenoid tubercle of scapula
short head: tip of coracoid process
biceps brachii - insertion
radial tuberosity and bicipital aponeurosis
biceps brachii - nerve innervation
musculocutaneous (C6)
biceps brachii - action
flexion of arm, internal rotation and adduction, forearm flexion and supination
coracobrachialis - origin
tip of coracoid process
coracobrachialis - insertion
middle half of medial surface of humerus
coracobrachialis - nerve innervation
musculocutaneous (C6)
coracobrachialis - action
flexion of arm, internal rotation and adduction
brachialis - origin
distal half of anterior, medial and lateral surface of humerus, medial and lateral inter muscular septum
brachialis - insertion
ulnar tuberosity
brachialis - nerve innervation
musculocutaneous (C6)
brachialis - action
forearm flexion
triceps brachii - origin
long head - infraglenoid tubercle of scapula
lateral head: proximal 1/3 of posterior humerus
medial head: distal 2/3 of posterior humerus and medial IM septum
triceps brachii - insertion
upper surface of posterior part of olecranon process of ulna
triceps brachii - nerve innervation
radial nerve (C7-C8)
triceps brachii - action
extension and hyperextension of arm
elbow extension
(arm adduction by long head)
anconeus - origin
posterior surface of lateral epicondyle of humerus
anconeus - insertion
lateral side of olecranon process and upper posterior surface of ulna
aconeus - nerve innervation
radial (C7-C8)
aconeus - action
forearm extension
pronator teres - origin
humeral head: medial supracondylar ridge of humerus and medial epicondyle of humerus via common flexor tendon ulnar head: medial margin of coronoid process of ulna
pronator teres - insertion
middle of lateral side of shaft of radius
pronator teres - nerve innervation
median (C7)
pronator teres - action
forearm pronation and flexion of elbow
flexor carpi radialis - origin
medial epicondyle of humerus by common flexor tendon (CFT)
flexor carpi radialis - insertion
base of 2nd and 3rd metacarpal
flexor carpi radialis - nerve innervation
median (C7)
flexor carpi radialis - action
forearm pronation, elbow flexion wrist flexion and abduction (radial deviation)
palmaris longus - origin
medial epicondyle of humerus by common flexor tendon (CFT)
palmaris longus - insertion
palmar aponeurosis
palmaris longus - nerve innervation
median (C7-8)
palmaris longus - action
forearm pronation, wrist flexion tenses palmar fascia
flexor carpi ulnaris - origin
humeral head: medial epicondyle of humerus via common flexor tendon (CFT) ulnar head: medial border of olecranon process and posterior border of ulna (upper 2/3) by common aponeurosis
flexor carpi ulnaris - insertion
pisiform bone and hook of hamate (by pisohamate ligt) and base of 5th metacarpal (by pisometacarpal ligt)
flexor carpi ulnaris - nerve innervation
ulnar (C8)
flexor carpi ulnaris - action
forearm flexion and wrist flexion adduction (ulnar deviation)
flexor digitorum superficialis - origin
humeral head: medial epicondyle by common flexor tendon (CFT) ulnar head: medial surface of coronoid process of ulna radial head: upper half of anterior border of radius
flexor digitorum superficialis - insertion
palmar aspect, sides of shafts, middle phalanges of fingers 2 to 5 by split tendon
flexor digitorum superficialis - nerve innervation
median (C8)
flexor digitorum superficialis - action
forearm flexion, wrist flexion finger flexion at MPs and proximal IPs