Supraspinatus

Origin: Supraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Extends shoulder

Infrapsinatus

Origin: Infraspinous fossa of scapula

Insertion: Greater tubercle of humerus

Action: Flexes shoulder/abducts limb

Serratus Ventralis

Origin: Cervical vertebrae and ribs

Insertion: Dorsomedial scapula

Action: Supports trunk

Subscapularis

Origin: Subscapular fossa of scapula

Insertion: Lesser tubercle of humerus

Action: Adducts limb/rotates forearm

Triceps brachii

Origin: Caudal border of scapula/proximal border of humerus

Insertion: Olecranon of ulna

Action: Extends elbow/flexes shoulder

Brachialis

Origin: Caudolateral aspect of proximal humerus

Insertion: Ulna and radial tuberosities

Action: Flexes elbow

Biceps brachii

Origin: Supraaglenoid tubercle of scapula

Insertion: Ulna and radial tuberosities

Action: Flexes elbow/extends shoulder

Muscles responsible for extending forearm

Supraspinatus

Triceps brachii

Extensor carpi radialias

Lateral digital extensor

Abductofr policis longus