Purpose: To determine the effectiveness of a single 10-min postural repositioning session on the maximum phonation duration (MPD) of the vowel/a/in individuals with acquired dysarthria.
Materials and methods: A pre-post interventional design was implemented; five patients with dysarthria (PWDs) underwent a single 2-hour experimental session. MPD capacities were assessed before and immediately after a 10-min postural repositioning intervention by a physical and occupational therapist. Five age- and sex-matched individuals without dysarthria were recruited as controls. The main outcome measure was the MPD of the vowel/a/at conversational and louder voice levels, with a speech-and-language therapist standing 1 and 6 m away, respectively. Secondary outcome measures were thoracic expansion, manometry, electromyographic recordings of axial muscles and perceived effort.
Results: In PWDs, postural repositioning improved the MPD during the/a/-1-m (80.3% increase) and/a/-6-m tasks (18% increase), increased thoracic expansion and manometric measurements, and reduced the perceived effort necessary to perform the tasks. A triphasic electromyographic pattern was observed during both/a/-1-m and/a/-6-m tasks in controls, but was absent in participants with severe dysarthria, even after postural repositioning. Nonetheless, postural repositioning enabled an earlier onset of EMG activity prior to voice production.
Conclusions: These data suggest the efficacy of postural repositioning in improving phonatory capacities essential for voice production in PWDs.
Keywords: Acquired dysarthria; corrected seated posture; electromyographic patterns; maximum phonation duration; transdisciplinary approach.