shoulder

muscles

100

Serratus Anterior

O: 

I: 

A:

N:

O: Lateral surface of the upper eight ribs

I: Vertebral border of the scapula, anterior surface

N: Long thoracic

A: Scapula protraction and upward rotation

200

Upper Trapezius

O: 

I: 

N:

A:

O: Occipital bone, nuchal ligament

I: Outer third of clavicle, acromion process

N: Spinal accessory

A: Scapular elevation and upward rotation

300

Middle Trapezius

O: Spinous processes of C7 - T3 

I: Scapular spine

N: Spinal accessory nerve

A: Scapular retraction

400

Lower Trapezius

O: Spinous process (T3-T12) of middle and lower thoracic vertebrae 

I: Base of the scapular spine

N: Spinal accessory

A: Scapular depression

500

Levator Scapula 

O: Transverse processes of the first four cervical vertebrae

I: Vertebral border of scapula 

N: Dorsal Scapular nerve

A: Scapular elevation and downward rotation 

muscle

100

Rhomboid 

O: Spinous processes of C7 - T5 

I: Vertebral border of scapula between the spine and inferior angle 

N: Dorsal scapular nerve

A: Scapular retraction and downward rotation 

200

Serratus Anterior

O: Lateral surface of the upper eight ribs

I: Vertebral border of the scapula, anterior surface

N: Long thoracic nerve

A: Scapular protraction and upward rotation

300

Pectoralis Minor

O: Anterior surface, 3rd-5th ribs

I: Coracoid process of the scapula 

N: Medial pectoral nerve

A: Scapular depression, protraction, downward rotation 

400

Supraspinatus 

O: Supraspinatus fossa of the scapula 

I: Greater tubercle of the humerus

N: Suprascapular nerver 

A: Stabilizes the head of the humerus, initiates GH abduction 

500

Infraspinatus

O: Infraspinatus fossa of scapula 

I: Greater tubercle of humerus

N: Suprascapular nerve 

A: Shoulder external rotation, stabilizes head of humerus in glenoid cavity, horizontal abduction of humerus

muscle

100

Teres Minor 

O: Axillary border of scapula

I: Greater tubercle of humerus

N: Axillary nerve (C5)

A: Shoulder external rotation, stabilizes 

head of humerus in glenoid cavity, 

horizontal abduction of humerus

200

Subscapularis

O: Subscapular fossa of the scapula

I: Lesser tubercle of the humerus

N: Upper and lower subscapular nerves (C5,C6)

A: Shoulder internal rotation, stabilizes 

head of humerus in glenoid cavity

300

Anterior Deltoid 

O:Lateral third of the clavicle

I: Deltoid tuberosity

N: Axillary nerve (C5,C6)

A:Shoulder flexion, internal rotation, and 

horizontal adduction

400

Middle Deltoid 

O: Acromion process

I: Deltoid tuberosity

N:Axillary nerve (C5,C6)

A:Shoulder abduction

500

Posterior Deltoid 

O: Spine of Scapula

I: Deltoid tuberosity

N: Axillary nerve (C5,C6)

A:Shoulder extension, lateral rotation, 

horizontal abduction

muscle

100

Triceps Brachii

O:Longhead:  infraglenoid tubercle

Lateral head:  humerus proximal to radial groove

Medial Head:  humerus distal to radial groove

I:  Olecranon of ulna

N:Radial nerve (C7, C8)

A:elbow extension and assists 

shoulder extension

200

Bicep Brachii

•

O: LONG HEAD:  supraglenoid tubercle

SHORT HEAD:  coracoid process

I: Radial tuberosity

N: Musculocutaneous nerve (C5,C6)

A: Elbow flexion and forearm supination, 

assist shoulder flexion (long head)

300

Teres Major

O:Axillary border of scapula near the 

inferior angle

I: Medial lip of intertubercular sulcus

N:Lower subscapular nerve (C5, C6)

A:Shoulder extension, adduction, medial 

rotation

400

Latissimus Dorsi

O: Spinous processes of T7 through L5 

(via thoracolumbar fascia), posterior 

surface of sacrum, iliac crest, and lower 

three ribs

I: Medial lip of bicipital groove of 

humerus

N: Thoracodorsal nerve (C6-C8)

A:Shoulder extension, adduction, medial 

rotation

500

Pectoralis Major

O: Medial 1/3 of clavicle, sternum, costal cartilages and external, surface of upper 6 ribs

I:Lateral border of bicipital groove

N:Lateral and medial pectoral nerve

A: Flexion of GH joint to 60/90 degrees (clavicular), extension from flexed position (sternal), medial rotation, shoulder adduction, horizontal adduction.