Conversation so far:
which muscle inserts on the lesser tubercle of the humerus
The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the shoulder-joint capsule.
what is the function of the subscapularis muscle
The subscapularis rotates the head of the humerus medially and adducts it; when the arm is raised, it draws the humerus forward and downward.
where is the origin of the subscapularis muscle
The subscapularis originates from the subscapular fossa of the scapula.

Question: what are the actions
Self-contained rewrite: what are the actions of the subscapularis muscle