The diaphragm, which separates the thoracic and abdominal cavities, is the most important muscle of respiration. It contributes up to 70% of tidal volume while the rest of the contribution comes from intercostal and accessory muscles. It has a central tendinous portion and a circumferential contractile muscular portion. Diaphragmatic disorders can be classified based on anatomical and neurological etiology, or if the involvement is unilateral or bilateral. The chest wall consists of a bony thoracic cage and various muscles of respiration. Primary disorders of the chest wall may be due to impairment of the neuromuscular apparatus or the bony thoracic cage.