In many countries, PAP machines are only available by prescription. A sleep study at an accredited sleep lab is usually necessary before treatment can start. This is because the pressure settings on the PAP machine must be tailored to a patient's treatment needs.
The pectoralis major muscle also performs internal rotation -- turning your arm in toward your body. This action, also called medial rotation, is important for reaching behind your back to tuck in your shirt and combing your hair on the opposite side of your head.
However, your feedback is important to us. 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. A developed pectoralis major is most evident in males, as the breasts of a female typically hide the pectoral muscles. A second pectoral muscle, the pectoralis minor, lies beneath the pectoralis major.