Thoracic cirtometry in children with Duchenne muscular dystrophy--expansion of the method.

BACKGROUND: Thoracic cirtometry is a simple and accessible technique to evaluate chest mobility during forced breathing. However, it does not allow for the assessment of compensatory movements commonly used by people with chronic diseases, such Duchenne muscular dystrophy (DMD). DMD is a condition characterized by progressive and irreversible degeneration of the musculoskeletal system.

OBJECTIVES: To expand the method of thoracic cirtometry to allow for the assessment of compensatory movements; to analyze the reliability of the tool; and to describe thoracic mobility of children with DMD during deep breathing.

METHOD: Sixty boys, 30 with DMD (10.1±0.5 years) and 30 healthy controls (9.5±0.6 years) participated in the study. The expanded thoracic cirtometry was organized in two phases: 1. the body could move freely, allowing the assessment of compensatory movements (free thoracic cirtometry) and 2. the body without compensatory movements, allowing for the direct study of the movements of the chest (guided thoracic cirtometry). This method includes videotaping and systematic observation of body movements using descriptive and numeric data. We investigated reliability of these measures in both groups.

RESULTS: Measures of axial and the xiphoid thoracic cirtometry (both free and guided) showed excellent reliability. All measures were significantly different between groups. In DMD boys, free thoracic cirtometry presented a greater value of chest expansion when compared with the guided measures, which probably occurred due to compensatory movements. The most commons were movements of the head, shoulder and torso.

CONCLUSIONS: The expanded thoracic cirtometry method showed excellent reliability and achieved the objectives of determining measures of chest mobility and compensatory movements during deep breath. We suggested its use in the respiratory evaluation of children with DMD.