Expiratory Muscle Training and Trunk Flexion in Parkinson's Disease

After the 4-week wait-to-start period during which they will not receive any intervention, will participants undergo a 4-week respiratory training program using the EMST150™ device (Expiratory Muscle Strength Trainer). EMST therapy sessions will be completed at home on 5 days (of the patients choosing) per week, performing five sets of five forceful exhalations through the EMST150™. The resistance of the device will be set to 75% of the patient's individual maximum expiratory pressure (MEP). The daily training will take approximately 15 minutes. Following the training period, patients will be observed for an additional 4 weeks to assess the sustainability of the potential training effects.