Test 4 Muscles

Front 1

Supraspinatus

Back 1

Origin: Supra-spinous fossa of scapula

Insertion: Greater tubercle of humerus

Joint action: initiates humeral abduction, stabilizes teh humerus during abduction

Pulls the head of the humerus into the glenoid fossa

Front 2

Infraspinatus

Back 2

Origin: Infra-spinous fossa of scapula

Insertion: Greater tubercle of humerus

Joint action: Later rotation , extension of the jumerus
Reinforces the capsule of the shoulder joint

Front 3

Teres Minor

Back 3

Origin: upper 2/3 of axillary border of scapula

Insertion: grater tubercle of humerus

Joint Action: Lateral rotation, extension of the humerus

Front 4

Subscapularis

Back 4

Origin: subscapular fossa of scapula

Insertion: Lesser tubercle of humerus

Joint action: Medial rotation of the humerus, adduction of the humerus

Front 5

Biceps Brachii

Back 5

Short head/long head
Origin: Short head - coricoid process of scapula
Long head: Supraglenoid tubercle of scapula

Insertion: Tuberosity of radius, Bicipital aponeurosis

Joint action: Elbow flexion, Shoulder flexion, supination of the forarm
Short head: flexion of the humerus

Front 6

Brachialis

Back 6

Origin: Lower half of the anterior shaft

Insertion: Tuberosity of ulna, coronoid process of ulna

Joint Action: Elbow Flexion
**Most valuable position among the elbow flexiors

Front 7

Brachioradialis

Back 7

Origin: Lateral supracondylar ridge of humerus

Insertion: Styloid process of radius

Joint action: Elbow flexion (In nutral postion thumbs upward)