A Study of Respiratory Muscle Strength in Patients With Late-onset Pompe Disease (LOPD)

Inclusion Criteria: * Willing and able to provide written informed consent, after the nature of the study has been explained, and prior to any study-related procedures * Documented diagnosis with late-onset Pompe disease - At least 18 years of age at study entry * Willing and able to comply with all study procedures Exclusion Criteria: * Requires ventilatory support while awake and in the upright position * Concurrent disease, medical condition, or extenuating circumstance that, in the opinion of the investigator, might compromise patient well-being, study completion, or data collection * Allergy to tools or procedures used for respiratory muscle testing