Pectoralis Major

The pectoralis major is one of the muscles in the pectoral region of the thorax. The other muscles in this region include the pectoralis minor and the subclavius. The pectoralis minor lies underneath the pectoralis major, and is a much smaller muscle – hence the name. The subclavius, as the name suggests, is located under (“sub”) the clavicle (“clavius”), attaching at one end to the bottom of the clavicle. And at the other to the first rib. The pectoralis major muscle has a few actions at the shoulder joint:

• flexion
• adduction
• medial rotation

There are two main parts to the pectoralis major: the clavicular part and the sternocostal part. Gym enthusiasts spend a lot of time training their pectoral muscles using a variety of horizontal pressing movements, and movements which involve horizontal adduction of the arms. The key exercises being variations of the bench press and “flyes”. Check out our 3D atlas where you can visualise and interact with these muscles for yourself. What exercises do you like to use to train your pectoral muscles?