Serratus Anterior
Origin: series of muscle branches from first 8 ribs
Insertion: entire anterior surface of medial border of scapula
Action: rotates scapula so its inferior angle moves laterally and upwards
Trapezius
origin:
spinous processes of C7 and all thoracic vertebrae
occipital bone
ligamentum nuchae
insertion:
lateral third of clavicle
acromion of scapula
spine of scapula
action: stabilizes, elevates, retracts, and rotates scapula
Latissimus Dorsi
origin:
indirect attachment via lumbodorsal fascia into spines of last 6 thoracic vertebrae
last 3 or 4 ribs
iliac crest
insertion: spirals around teres major to insert in floor of tubercular sulcus of humerus
action: prime mover of arm extension, powerful arm adductor, medially rotates arm
supraspinatus
origin:
supraspinous fossa of scapula
Insertion:
superior part of greater tubercle of humerus
action:
initiates abduction of arm
infraspinatus
origin: infraspinous fossa of scapula
insertion: greater tubercle of humerus posterior to insertion of supraspinatus
action: rotates arm laterally
subscapularis
origin: subscapular fossa of scapula
insertion: lesser tubercle of humerus
action: rotates arm medially
teres minor
origin: lateral border of dorsal scapular surface
insertion: greater tubercle of humerus inferior to infraspinatous insertion
action: rotates arm laterally
teres major
origin: posterior surface of scapula at inferior angle
insertion:
-crest of lesser tubercle on anterior humerus
-insertion tendon fused with that of latissimus dorsi
action:
extends, medially rotates, and adducts arms
rhomboids
origin: spinous processes of C7 and T1
spinous processes of T2-T5
Insertion: medial border of scapula
Action: stabilize scapula
Levator scapulae
Deltoid
Origin:
lateral third of clavicle
acromion and spine of scapula
insertion: deltoid tuberosity of humerus
action: primer mover of arm abduction when all its fibers contract simultaneously
Biceps Brachii
Origin:
short head; coracoid process
long head; supraglenoid tubercle and lip of glenoid cavity
tendon of long head into intertubercular sulcus
Insertion: by tendon into radial tuberosity
action: flexes and supinates forearm
Brachialis
Origin: anterior surface of distal humerus
Insertion: coronoid process of ulna and capsule of elbow joint
action: a major forearm flexor
Triceps Brachii
Origin:
long head; infraglenoid tubercle of scapula
lateral head: posterior shaft of humerus
medial head: posterior shaft of humerus distal to radial groove
Insertion:
common tendon into olecranon of ulna
action: powerful forearm extensor
Pronator teres
Flexor Carpi Radialis
Flexor Carpi Ulnaris
Flexor digitorum superficialis
Flexor digitorum profundus
brachioradialis
extensor carpi radialis longus
extensor carpi radialis longus
extensor carpi radialis brevis
extensor digitorum
supinator
supinator