Expiratory Muscle Training in Parkinson's Disease With Forward Trunk Flexion

Effect of Expiratory Muscle Strength Training in Patients With Parkinson's Disease and Forward Trunk Flexion: A Pilot Study

Postural abnormalities (PA) negatively affecting the axial system are part of the symptoms of Parkinson's disease (PD). They occur in more than 20% of patients with PD especially in more advanced stages of the disease, contribute significantly to patient disability, affect respiratory functions, and reduce quality of life. Eighty-five percent of patients with forward trunk flexion (FTF) reported difficulties with swallowing (dysphagia), shortness of breath, and drooling. Previous studies in patients with PD also identified cough disorders (dystussia). Since cough and properly functioning swallowing are key mechanisms for airway protection, impairments in these functions lead to a higher risk of aspiration. The seriousness of this problem is clearly confirmed by the fact that aspiration pneumonia is the leading cause of death in patients with PD.

Among non-pharmacological interventions for airway protection, expiratory muscle strength training (EMST) has been shown to be beneficial in patients with PD. Recent randomized controlled studies demonstrated a significant effect of EMST on dysphagia, dystussia, drooling, and dysarthria in patients with PD.

However, the literature lacks data on the effect of EMST on dystussia in patients with PD and FTF, who, according to previous research, are also affected by restrictive ventilatory impairment, which negatively affects respiratory capacity and, in particular, cough strength.

The aim of this study is to evaluate the effect of EMST on cough, swallowing, respiratory muscle strength, and drooling in patients with PD and forward trunk flexion.

Inclusion Criteria:

• Diagnosis of Parkinson' s disease
• Age ≥ 18 years
• MoCA score (Montreal Cognitive Assessment) ≥ 19
• Score II-IV during the "ON" phase under regular antiparkinsonian medication according to the Modified Hoehn and Yahr Scale
• Pathological forward trunk flexion defined as thoracic (≥ 25°) or lumbar flexion (> 15°) during standing and walking, which completely disappears in the supine position (for the experimental group only)

Exclusion Criteria:

• Change in antiparkinsonian medication within the last 3 months prior to study enrollment
• Other neurological, orthopedic, cardiovascular, or respiratory comorbidities
• Inability to cooperate due to neuropsychological dysfunction
• Current smoking history
• Inadequate lip seal