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.
When the raised arms are fixed (as in mountain climbing), it assists the latissimus dorsi and teres major muscles in pulling the trunk up. The pectoralis minor lies, for the most part, beneath the pectoralis major, arising from the middle ribs and inserting into (attaching to) the scapula (shoulder blade). It aids in drawing the shoulder forward and downward (in opposition to the trapezius muscle).