Teres Minor

origin: axillary border of scapula

insertion: greater tubercle of humerus

action: stabilizes shoulder joint (lateral rotator)

Teres Major

origin: glenovertebral angle of scapula

insertion: intertubercular sulcus of humerus

action: retractor of humerus

Supraspinatus

origin: supraspinous fossa of scapula

insertion: greater tubercle of humerus

action: stabilizes shoulder joint (lateral rotator)

Triceps

long head

origin: axillary border of scapula

insertion: olecranon process of ulna

action: extend forearm at elbow, retract arm at shoulder

Pectoralis Major

origin: pars capularis - capsule of claviculosternal joint

pars sternalis - midline of sternum

insertion: border of intertubercular sulcus of humerus

action: depresses arm when elevated, adducts humerus

Pectoralis Minor

origin: body of sternum

instertion: capsule of shoulder joint

action: mostly depressor of forelimb, also inward rotator of humerus

Pectoralis Abdominalis

origin: sheath of rectus abdominis muscle

insertion: on humerus distal to capsule

action: aids pectoralis minor

Panniculus Carnosus

origin: fascia covering thigh, gluteal region, lumbar region

insertion: humerus, via deep pectoral aponeurosis

action: moves skin. May help pectorals in depressing arms

Serratus Anterior

origin: cervical portion - cervical vertebrae transverse process

thoracic portion -ribs

insertion: vertebral border of scapula

action: stabilizes vertebral border of scapula

Subscapularis

origin: ventral surface of scapula

insertion: lesser tubercle of humerus

action: medial rotator of humerus, fixes humerus

Biceps Brachii

origin: short head - coracoid process

long head - supraglenoid tubercule of scapula

insertion: bicipital tuberosity of radius

action: flexes forearm at elbow, supinates forearm at elbow

Coracobrachialis

origin: common coracoid tendon

insertion: medialis- humerus

profundus - surgical neck of humerus

action: medialis - protraction of arm at shoulder

profundus - medial rotator of humerus

Dorsoepitrochlearis

origin: latissimus dorsi muscle

insertion: olecranon process of ulna; medial epicondyle of humerus

action: aid latissimus dorsi and long head of tricpes in retracting forelimb

Triceps Brachii

origin: lateral - posterolateral portion of humeral shaft

medial - posterior face of humerus

insertion: both on olecranon process of ulna

action: extend forearm at elbow

Subclavius

origin: first costal (rib) cartilage

insertion: clavicle

action: fixes acromioclavicular joint

Brachialis

origin: humeral shaft, especially laterally and distally on brachialis flange

insertion: coranoid process of ulna

action: flexes forearm at elbow

Trapezius

origin: occipital bone

insertion: spine of scapula

action: adducts scapula

Deltoideus

origin: clavicle, acromion, caudal border of scapular spine, glenovertebral angle

insertion: deltoid crest of humerus

action: protracts, abducts, restracts arm

Latissimus Dorsi

origin: midline of body. Thoracic and lumbodorsal vertebrae

insertion: axilla, intertubercular sulcus of humerus

action: chief retractor of arm

Rhomboideus

origin: along midline, from occipital bone to first 6 or 7 thoracic vertebrae

insertion: vertebral border of scapula, from region of scapular spine to glenovertebral angle

action: adducts scapula

Levator Scapulae

(Atlantoscapularis)

origin: transverse process of atlas

insertion: lateral scapular spine plus acromion; vertebral border of scapula

action: lifts or elevates scapula; tilts upward vertebral border of scapula

Infraspinatus

origin-infraspinous fossa of scapula

insertion - greater tubercle of scapula

action - stabilizes shoulder joint