Rhomboid major
ORIGIN:
spinous processes of T2-T5.INSERTION:
medial border of the scapula.ACTION:
Rhomboid minor and Rhomboid major are working together as a whole to perform the movement.retract scapula (squaring shoulders), synergist with middle fibers of Trapezius.
rotate glenoid cavity downward (lowering arm against resistance).
stabilize scapula.