thorasic muscles

Trapezius

Origin: Dorso-medial neck

& spinous processes of

thoracic vertebrae

• Insertion: Scapular spine

• Function: Elevates and

moves the shoulder forward

& backward

Latissimus Dorsi

• Origin: Dorsal thoraco-

lumbar region

• Insertion: Medial

aspect of humerus b.

• Function: Flexes the

shoulder

Brachiocephalicus

• Origin: Clavicle

• Insertion: Skull & Cranial

distal humerus b.

• Function: Flexes the neck

laterally & extends the

shoulder

Superficial Pectoral

• Origin: Sternum

• Insertion: Cranial humerus b.

• Function: Extends the

shoulder & Adducts the limb

Deep Pectoral

• Origin: Sternum

• Insertion: Greater &

Lesser tubercles of the

humerus b.

• Function: Flexes the

shoulder & Adducts the

limb

Supraspinatus

• Origin: Supraspinous fossa

• Insertion: Greater & lesser

tubercles of the humerus b.

• Function: Stabilizes & Extends

the shoulder

Infraspinatus

• Origin: Infraspinous fossa

• Insertion: Greater tubercle of the

humerus b.

• Function: Stabilizes & flexes the

shoulder

Deltoid

• Origin: Scapular spine &

Acromion process

• Insertion: Deltoid tuberosity

of the humerus b.

• Function: Flexes the shoulder

Subscapularis

• Origin: Subscapular fossa

• Insertion: Lesser tubercle

of the humerus b.

• Function: Extends the

shoulder & Adducts the

limb

Triceps brachii

• Origin: Caudal edge of scapula

b. & proximal humerus b.

• Insertion: Olecranon of the

ulna b.

• Function: Extends the elbow &

Flexes the shoulder

Biceps Brachii

• Origin: Supraglenoid tubercle

of the scapula b.

• Insertion: Proximal radius b.

• Function: Extends the

shoulder & Flexes the elbow

Extensor carpi radialis

• Origin: Lateral epicondyle of

humerus b.

• Insertion: Dorsal metacarpal b(s).

• Function: Flexes the elbow &

Extends the carpus.

Common digital extensor

Pink

• Origin: Lateral epicondyle of the

humerus b.

• Insertion: Dorsal surface of the

distal phalanx b(s).

• Function: Extends the carpus &

digits (ALL DIGITS)

Lateral Digital extensor

Blue

• Origin: Lateral epicondyle of the

humerus b.

• Insertion: Middle phalanx b(s).

• Function: Extends the carpus & digits

(ONLY 3, 4, 5 in dogs)

Flexor carpi radialis

Pink

• Origin: Medial epicondyle of the

humerus b.

• Insertion: Palmar surface of

proximal metacarpal b(s).

• Function: Flexes the carpus

Flexor carpi ulnaris

Blue

• Origin: Olecranon of the ulna b. &

Medial epicondyle of the humerus b.

• Insertion: Accessory carpal b.

• Function: Flexes the carpus

Superficial digital flexor

Pink

• Origin: Medial epicondyle of the

humerus b.

• Insertion: Palmar surface of the

middle phalanx b(s).

• Function: Flexes the carpus & digits

Deep digital flexor

Blue

• Origin: Humerus, Radius & Ulna b.

• Insertion: Palmar surface of the

distal phalanx b(s).

• Function: Flexes the carpus & digits

Pink - Trapezius

Blue - deep pectoral

Purple - deltoid

Yellow - biceps

Pink - subscapularis

Blue - supraspinatus

Purple - biceps brachii

Yellow - triceps brachii

Green - flexor carpi ulnaris

Red - deep digital flexor

Orange - flexor carpi radialis

Navy - superficial digital flexor