When people want to start exercising more, one of the first muscles they want to work on is their chest. Most people have heard of large muscle pectoralis major but seem to forget about pectoralis minor. Both need to work together in order to function at their highest capacity.

The pectoralis major muscle is a large muscle in the upper chest, fanning across the chest from the shoulder to the breastbone. The two pectoralis major muscles, commonly referred to as the “pecs,” are the muscles that create the bulk of the chest. The pectorals are predominantly used to control the movement of the arm and also play a part in deep inhalation, pulling the ribcage to create room for the lungs to expand. Six separate sets of muscle fibers are identified within the pectoralis major muscle. This enables each portion of the pectoralis major muscle to be moved separately by the nervous system.

The pectoralis minor is a thin, flat muscle found immediately underneath the pectoralis major. This is the s...