Origin: External occipital protuberance' ligamentum nuchae (on cervical vertebrae), and medial portion of the superior nuchal line

Insertion: Posterior- superior aspect of the lateral one third of the clavicle

 Action:

• Elevation of the scapula 
• Upward rotation of the scapula (with serratus anterior and lower trapezius) 

Nerve: Spinal accessory nerve (cranial nerve XI)

Origin: anterior surface of the lateral aspect of the clavicle  

Insertion: Deltoid tuberosity of the humerus 

 Action:  

• Flexion of the shoulder 
• Horizontal adduction of the shoulder 
• internal rotation of the shoulder 
• abduction of the shoulder

Nerve: Axillary nerve

Origin:  Superior lateral surface of the acromion   

Insertion: Deltoid tuberosity of the humerus 

 Action:   

• Abduction of the shoulder
• Flexion of the shoulder

Nerve: Axillary nerve

Origin: spine of the scapula 

Insertion: Deltoid tuberosity of the humerus 

 Action: 

• Extenison of the shoulder 
• Horizontal abduction of the shoulder 
• external rotation of the shoulder 
• abduction of the shoulder

Nerve: Axillary nerve

Origin: Suprapinatus fossa

Insertion: Greater tubercle of the humerus

 Action: 

• Shoulder Abduction 
• Stabilization of the GH joint 

 Nerve: Suprascapular nerve

Origin: Infraspinatus fossa

Insertion: Greater tubercle of the humerus

 Action: 

• External rotation of the Shoulder  
• Stabilization of the GH joint 

 Nerve: Suprascapular nerve

Origin: Posterior surface of the lateral border of the scapula; near the inferior angle

Insertion: Greater tubercle of the humerus (lower facet)

 Action: 

• Shoulder Adduction
• Stabilization of the GH joint 
• External rotation of the shoulder 

 Nerve: Axillary nerve 

Origin: Inferior angle of the scapula

Insertion: Crest of the Lesser tubercle of the humerus 

 Action: 

• Shoulder Adduction
• Shoulder Extension 
• Internal rotation of the shoulder 

 Nerve: Lower Subscapular nerve

Origin: Subscapular Fossa

Insertion: Lesser tubercle of the humerus 

 Action: 

• Internal rotation of the shoulder 
• Stabilization of the GH joint

 Nerve: Lower and Upper Subscapular nerves

Origin: Thoracolumbar fascia, spinous processes of the lower thoracic and all lumbar vertebrae, the posterior crest of the ilium, the lower four ribs, and the inferior angle of the scapula 

Insertion: Floor of the intertubercular groove of the humerus

 Action: 

• Shoulder Adduction
• Shoulder Extension 
• Internal rotation of the shoulder
• Scapular Depression 

 Nerve: Thoracodorsal Nerve (middle subscapular)

Origin: Clavicular head: anterior margin of the medial portion of the clavicle 

          Sternal head: Lateral margin of the manubrium and body of the sternum and cartilages of the first six to seven ribs

Insertion: Crest of the Greater tubercle of the humerus 

 Action: Clavicular Head: 

• Flexion of the shoulder 
• Horizontal adduction of the shoulder
• Internal rotation of the shoulderSternal Head:
• Internal rotation of the shoulder 
• Shoulder Depression
• Shoulder Adduction 

 Nerve: Clavicular Head: Lateral pectoral nerve

            Sternal Head: Lateral and medial pectoral nerves

Origin: Ligamentum nuchae and spinous processes of C7-T5

Insertion: Medial border of the scapula from the root of the scapular spine to the inferior angle of the scapula

 Action: 

• Retraction of the scapula
• Elevation of the scapula
• Downward rotation of the scapula

 Nerve: Dorsal scapular nerve

Origin: Spinous processes of the middle and lower thoracic vertebrae (T6-T12)

Insertion: Upper lip of the spine of the scapula near the medial border

 Action: 

• Retraction of the scapula
• Upward rotation of the scapula
• Scapular Depression 

 Nerve: Spinal Accessory nerve (cranial nerve XI)

Origin: External surface of the lateral region of the first nine ribs

Insertion: Entire medial border of the scapula with a concentration of fibers near the inferior angle

 Action: 

• Protraction of the scapula
• Upward rotation of the scapula
• Holds the scapula firmly against the posterior thorax

 Nerve: Long Thoracic nerve

Origin: Ligamentum nuchae and spinous processes of C7-T5

Insertion: Retraction of the scapula

 Action: 

• Retraction of the scapula

 Nerve: Spinal Accessory Nerve (cranial nerve XI)