Axillary border of the scapula to greater tubercle of humerus.
The Teres Minor muscle origin is on the dorsal surface of the middle half of the lateral border of the scapula.
Inferior facet of greater tubercle of the humerus.
Its point of insertion is the lowest of the three facets of the greater tubercle of the humerus.
Extends arm at shoulder.
Adducts and rotates the head of the humerus externally and pulls the humerus toward the glenoid fossa. American Academy of Manual Medicine
Innervation – Nerve control
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein. Wiki
Posterior circumflex humeral artery and the circumflex scapular artery.
The posterior humeral circumflex artery (posterior circumflex artery, posterior circumflex humeral artery) arises from the axillary artery at the lower border of the subscapularis, and runs posteriorly with the axillary nerve through the quadrangular space.
It winds around the neck of the humerus and is distributed to the deltoid muscle and shoulder-joint, anastomosing with the anterior humeral circumflex and deep artery of the arm. Wiki
Subscapularis, Pectoralis major, Anterior Deltoid.
Pictures of muscles
Trigger Point Referrals