Study Assessing High-Frequency Chest Wall Oscillation (HFCWO) in Preventing Pulmonary Exacerbations

Inclusion Criteria: * Subject is at least 18 months old. * Subject has a chest circumference of greater than 19 inches. * Subject has a diagnosis of muscle weakness and restrictive lung disease. * Ability to provide Informed consent from legal guardian. * Subject has had 2 or more exacerbations requiring either hospitalization or antibiotics (IV or oral) in the past 12 months * If inhaled Tobramycin has been prescribed prophylacticly, subjects must discontinue the medication at least 2 weeks prior to study enrollment Exclusion Criteria: * Subject has a diagnosed allergy with a respiratory trigger. * Participation in another clinical trial. * Unstable head or spinal injury. * Unresolved pneumothorax or pneumomediastinum present * Unresolved hemorrhage * Hypotension requiring vasopressors or positioning * Bronchopleural fistula * Gross hemoptysis within the past eight hours * Pulmonary embolism or history of pulmonary embolism within the past two months * Burns, open wounds and skin infections on the thorax * Osteomyelitis of the ribs * Osteoporosis with history of fractures.