You can elect to use a 52-53-week tax year if you keep your books and records and report your income and expenses on that basis. If you make this election, your 52-53-week tax year must always end on the same day of the week.
Forced Inhalation. Involved in the mechanics of breathing; The muscles involved in this type of breathing are the diaphragm, the external intercostal muscles, and the accessory respiratory muscles (activated when respiration increases significantly).
Breathing is a task that involves some of the back muscles, which is why pain in the upper back when breathing is often a sign of a pulled or sore muscle. The upper back muscles may be injured, though lower back, abdominal, and diaphragm muscles are also often affected by every breath.