Teres major is only functional when the Rhomboids fix the scapula. This muscle mainly helps Latissimus dorsi.
Origin : Lower 1/3 of the lateral border of the scapula.
Insertion : Intertubercular goove (between the greater and lesser tubercles) of the humerus.
Actions : Shoulder adduction.
Innervation : Lower subscapular nerve.
Daily uses : Tucking the back of your shirt into your trousers.
Example strengthening exercises : Shoulder internal rotation.
Example stretches : External rotation stretch.