Feasibility and Preliminary Effects of Oropharyngeal Alignment Exercise on Swallowing Function in Neurological Disorders with Restricted Mouth Opening: A Pilot Study

Purpose This single-arm pilot study evaluated the feasibility and tolerability of an oropharyngeal alignment exercise (OAE) protocol and explored preliminary changes in swallowing and mouth-opening capacity in individuals with neurological disorders presenting with dysphagia and restricted mouth opening. Methods Of 12 individuals screened, nine participants (seven with stroke, one with Parkinson's disease, one with cerebellar granule cell neuropathy) completed three phases of eight sessions each: baseline, intervention, and follow-up. OAE, targeting head and neck alignment and postural correction, was delivered twice weekly for four weeks alongside routine rehabilitation. Feasibility was assessed by recruitment, retention, adherence, and safety. Outcomes included maximum mouth opening (MMO), the Mann Assessment of Swallowing Ability (MASA), the Gugging Swallowing Screen (GUSS), and the Penetration–Aspiration Scale (PAS) from videofluoroscopy. Changes were examined using participant-specific baseline ±2SD bands and group-level non-parametric tests. Results Recruitment was 75.0%, retention and supervised-session attendance were 100%, caregiver-reported home-exercise adherence was complete during intervention, and no adverse events occurred. Most participants showed intervention- and follow-up-phase values exceeding their baseline ±2SD bands. MMO increased by 6–13 mm, exceeding the reported minimal detectable change in most participants. MMO, MASA, and GUSS showed statistically significant phase-related changes ( p < 0.05; Kendall's W = 0.70–0.97), as did PAS, with the largest effect for semisolid boluses. Conclusions OAE was feasible and well tolerated alongside routine rehabilitation. Preliminary phase-related changes were observed, warranting further evaluation in larger controlled trials with diagnostically homogeneous samples to determine the clinical relevance of OAE in neurological dysphagia.