Introduction
Breath management is a core element in classical singing technique, often described through the concepts of appoggio (support through coordinated breath control) and sostegno (maintenance of subglottic pressure). Despite their central role in vocal pedagogy, these concepts remain challenging to quantify objectively. Recent advances in ultrasonography allow non-invasive visualization of thoracoabdominal dynamics during phonation. The lower thoracic angle—formed by the costal margins at the anterior chest—has been proposed as a potential biomechanical marker of breath strategy in singers.

Objectives
This study aimed to: (1) explore the feasibility of using real-time ultrasonography to assess respiratory and postural adjustments in trained singers; (2) compare the lower thoracic angle during phonation tasks requiring appoggio versus sostegno; and (3) investigate whether angle differences correlate with singers’ self-reported breath management strategies.

Methodology
A cohort of classically trained singers underwent B-mode ultrasonographic assessment during standardized phonation tasks. Tasks were designed to elicit predominant appoggio and sostegno depending on the lower thoracic angle. The lower thoracic angle was measured before the task to predict the dynamic priority of each singer.

Results
Preliminary analysis demonstrated consistent feasibility of angle measurement across participants, with high inter-rater reliability. A higher angle was significantly related to a predominance into the appoggio and a lower angle was related to a higher need to use the sostegno in the former.

Conclusions
Having the visual feedback by ultrasonography of the different abdominal muscles and seing how they contract, it's useful for the singer to have an optimal control of the sostegno.