Shoulder Complex Actions

Anterior Deltoid Actions

Flexes the arm
Internally rotates the arm
Abducts the arm

GH joint

Middle Deltoid Actions

Abduction of the arm at the GH joint

Posterior Deltoid Actions

Extends the arm
Externally rotates the arm
Abducts the arm

GH joint

Coracobrachialis Actions

Flexes the arm

Adducts the arm

at the GH joint

Pectoralis Major Actions

Flexes the arm

Adducts the arm

Internally rotates the arm

At the GH Joint

Latissimus Dorsi Actions

Internal rotation of the arm

Adduction of the arm

Extension of the arm

“Handcuff muscle”

GH joint

Teres Major Actions

“Lat’s little helper”

Internally rotates the arm

Adducts the arm

Extends the arm

GH joint

Supraspinatus Actions

Abduction of the arm

External rotation of the arm

Stablizes/fixates the GH joint

Infraspinatus Actions

Externally rotates the arm at GH joint

Stabilizes the GH joint

Teres Minor Actions

Externally rotates the arm at the GH joint

Stablizes/fixates the GH joint

Subscapularis Actions

Internally rotates the arm

Stablizes/fixates the GH joint

Biceps Actions

Flexes the arm

Internally rotates the arm

Adducts the arm

GH joint

Triceps Actions

Extends the arm

Adducts the arm

Externally rotates the arm

GH joint

Upper Trapezius Actions

Adduction of the scapula (retraction)
Elevation of the scapula
Upward rotation of the scapula

ST joint

Middle Trapezius Actions

Adduction of the scapula (retraction)

ST joint

Lower Trapezius Actions

Adducts the scapula (retraction)
Depresses the scapula
Upwardly rotates the scapula

ST joint

Levator Scapulae Actions

Elevates the scapula at the ST joint

Rhomboid Minor Actions

Adducts the scapula (retraction)
Elevates the scapula

ST joint

Rhomboid Major Actions

Adducts the scapula (retraction)
Elevates the scapula

ST joint

Serratus Anterior Actions

Abducts the scapula (protraction)
Upwardly rotates the scapula

ST joint

Pectoralis Minor Actions

Abducts the scapula (protraction)
Depression of the scapula
Downward rotation of the scapula

ST joint