Chest wall DisordersThese disorders limit chest wall restriction and limit air intake. Review compliance and restriction Ankylosing spondylitis Ankylosing spondylitis is a systemic inflammatory disease that affects the joints of the axial skeleton. Pulmonary involvement can be both direct and indirect: Direct involvement is via the development of interstitial lung disease. Indirect involvement occurs when joints of the thoracic cage, such as the costovertebral joints, become fused; thus, movement is limited, and chest wall compliance is reduced. Kyphoscoliosis Kyphoscoliosis is characterized by abnormal curvatures in both the coronal and sagittal planes; the resulting rib displacement can restrict chest wall movement. Kyphoscoliosis is a combination of two skeletal abnormalities: – Kyphosis is characterized by a posterior curvature. – Scoliosis is characterized by a lateral curvature. When restriction of the pulmonary system is severe, hypoxemia can result. Hypoxemia is the root of two common pulmonary complications of kyphoscoliosis: pulmonary hypertension and cor pulmonale. Neuromuscular diseases Neuromuscular diseases that affect the thorax can also cause pulmonary restriction: • Guillain-Barre Syndrome • Myasthenia gravis • Poliomyelitis • Muscular dystrophies