The pectoralis major, teres major, lastissimus dorsi, and the carica adduct and medially, or internally, rotate the humerus.
The biggest and most visable is Pectoralis major; that is the "pecks" in slang terms.
which trunk muscle allows you to adduct your arms? which shoulder muscle allowed you to adduct your arm? which trunk muscle allows you to elevae your shoulders?
pectoralis
which shoulder muscle allows you to adduct your arm