Thoracic Limb myology

Superficial pectoral origin

cranial sternum

Superficial pectoral instertion

crest of greater tubercle, cranial border of humerus

Superficial pectoral action

Adduct the thoracic limb

Deep pectoral muscle origin

Sternum

Deep pectoral muscle insertion

Greater and lesser tubercles of humerus

Deep pectoral muscle action

adduct the thoracic limb and pull it caudally

Brachiocephalicus muscle origin

Clavicular intersection

Brachiocephalicus muscle insertion

distal cranial humerus, dorsal neck, mastoid process of temporal bone

brachiocephalicus muscle action

pull thoracic limb cranially when not bearing weight, depress head laterally when bearing weight

Omotransversarius muscle origin

Wing of the atlas

Omotransversarius muscle insertion

Distal Spine of the scapula

Omotransversarius muscle action

pull thoracic limb cranially when not bearing weight, depress and pull head laterally when bearing weight

Trapezius muscle origin (cervical)

Dorsal neck

Trapezius muscle origin (thoracic)

Dorsal thorax

Trapezius muscle insertion

Spine of the scapula

Trapezius muscle action

elevate the thoracic limb

Rhomboideus muscle origin

occipital bone, dorsal neck, dorsal thorax

Rhombiodeus muscle insertion

dorsal border of scapula and/or scapular cartilage

Rhomboideus muscle action

depress the scapula to the trunk and elevate the thoracic limb

Serratus ventralis muscle origin

Cervical vertebrae, ribs

Serratus ventralis muscle insertion

serrated face of scapula

Serratus ventralis muscle action

support and elevate the trunk

Latissimus dorsi muscle origin

thoracolumbar fascia

Latissimus dorsi muscle insertion

teres major tuberosity of humerus

Latissimus dorsi muscle action

draw thoracic limb caudally and flex humeral joint when not bearing weight; extend humeral joint when bearing weight

Sternocephalicus muscle caudal attachment

cranial sternum

Sternocephalicus muscle action

depress head/neck; draw head/neck laterally

Sternocephalicus muscle cranial attachment

mastoid process, occipital bone

Sternohyoideus muscle caudal attachment

cranial sternum

Sternohyoideus muscle cranial attachment

basihyoid bone

Sternohyoideus muscle action

pull tongue and larynx caudally

Sternothyroideus muscle caudal attachment

Cranial sternum

Sternothyroideus muscle cranial attachment

thyroid cartilage of the larynx

Sternothyroideus muscle action

pull tongue and larynx caudally

Deltoideus muscle origin

spine and acromion of scapula

deltoideus muscle insertion

deltoid tuberosity of humerus

deltoideus muscle action

flex humeral joint

Supraspinatus muscle origin

supraspinous fossa of scapula

supraspinatus muscle insertion

greater tubercle of the humerus

supraspinatus muscle action

extend the humeral joint

Infraspinatus muscle origin

infraspinous fossa of scapula

infraspinatus muscle insertion

greater tubercle of humerus

infraspinatus muscle action

flex the humeral joint

Teres minor muscle origin

caudal border of scapula

Teres minor muscle insertion

teres minor tuberosity of humerus

Teres minor muscle action

flex the humeral joint

Subscapularus muscle origin

subscapularis fossa

Subscapularis muscle insertion

Lesser tubercle of humerus

Subscapularis muscle action

adduct limb at humeral joint

Teres major muscle origin

caudal border of scapula

Teres major muscle insertion

teres major tuberosity of humerus

Teres major muscle action

flex the humeral joint

Biceps brachii muscle origin

supraglenoid tubercle of scapula

Biceps brachii muscle insertion

Proximal and medial aspects of radius and ulna

Biceps brachii muscle action

flex and extend cubital joint

Brachialis muscle action

flex cubital joint

Brachialis muscle origin

proximal part of lateral humerus

Brachialis muscle insertion

proximal and medial aspects of radius and ulna

Triceps brachii muscle origin (long head)

caudal border of scapula

Triceps brachii muscle origin (medical, accessory, and lateral heads)

Proximal humerus

Triceps brachii muscle insertion

tuber olecrani

Triceps brachii muscle action (all heads)

extend cubital joint

Triceps brachii muscle action (long head)

flex humeral joint

Tensor fascia antebrachii muscle origin

latissimus dorsi, fascia on caudal border of scapula

Tensor fascia antebrachii muscle insertion

tuber olecrani

Tensor fascia antebrachii muscle action

extend cubital joint

Anconeus muscle origin

caudal aspect of the distal humerus

Anconeus muscle action

extend the cubital joint

Anconeus muscle insertion

olecranon tuberosity

Extensor carpi radialis muscle origin

lateral epicondyle of humerus and its crest

Extensor carpi radialis muscle insertion

dorsoproximal end of metacarpal bones 2 & 3

Extensor carpi radialis muscle action

extend carpal joints

Common digital extensor muscle origin

lateral epicondyle of humerus

Common digital extensor muscle insertion

extensor processes of the distal phalanges

Common digital extensor muscle action

extend carpal and digital joints

Lateral digital extensor muscle origin

lateral epicondyle of humerus

Lateral digital extensor muscle insertion

distal phalanges of lateral digits

Lateral digital extensor muscle action

extend the carpal and digital joints

Ulnaris lateralis muscle origin

lateral epicondyle of humerus

Ulnaris lateralis muscle insertion

accessory carpal bone, lateral aspect of fifth metacarpal bone

Ulnaris lateralis muscle action

flex carpal joints; abduct the manus

Abductor pollicus [digiti 1] longus muscle origin

body of ulna

Abductor pollicus [digiti 1] longus muscle insertion

proximal metacarpal 1

Abductor pollicus [digiti 1] longus muscle action

extend the carpal joints; abduct first digit (cat)

Supinator muscle origin

lateral epicondyle of humerus

Supinator muscle instertion

body of radius

Supinator muscle action

supination of the manus

Brachioradialis muscle origin

lateral epicondyle of humerus

Brachioradialis muscle insertion

fascia near the carpus

Brachioradialis muscle action

flex the cubital joint and supinate the manus

Flexor carpi radialis muscle origin

medial epicondyle of humerus

Flexor carpi radialis muscle insertion

palmaroproximal aspect of metacarpal bones 2 & 3

Flexor carpi radialis muscle action

flex the carpal joint

Flexor carpi ularnis muscle origin

medial epicondyle of humerus, olecranon of ulna

Flexor cari ularnis muscle insertion

accessory carpal bone

Flexor cari ularnis muscle action

flex the carpal joints

Superficial digital flexor muscle origin

medial epicondyle of humerus

Superficial digital flexor muscle insertion

middle phalanges digits 2-5

Superficial digital flexor muscle action

flex carpal and digital joints, except distal interphalangeal joints

Deep digital flexor muscle insertion

distal phalanges, palmar aspects