The coracobrachialis is a deep muscle of the shoulder that often becomes tight and is especially susceptible to over-training injuries   This muscle is the smallest of the 3 muscles that attach to the coracoid process - the other two muscles that attach to the coracoid process are pec minor and the short head of the biceps.  Originating from the scapula and inserting into the humerus, the coracobrachialis allows us to adduct and flex our arms. It also works as a key stabiliser for the shoulder joint and plays a minor role in assisting internal rotation of the humerus.     In some cases the musculocutaneous nerve, which passes through the coracobrachialis, can become trapped - nerve entrapment.  In these...