Ultrasound evaluation of diaphragm mobility according to body positions in healthy subjects

Background : Ultrasound (US) has been proved a simple, well tolerated and reproducible method of assessing diaphragmatic movement. The influence of body postures on diaphragmatic mobility in healthy subjects by US evaluation is not fully established. Aims: To describe the right diaphragmatic mobility by US and to compare the effects of different postures (sitting and supine) on diaphragm motion. Methods: In12 healthy volunteers we performed an US of the right diaphragmatic to evaluate mobility during quiet breathing (QB) and deep breathing (DB) both in supine and sitting position. We also evaluated the superficial electromyography (EMG) of external oblique abdominal muscle and sternocleidomastoid (Sc). Results: There were 6 male, age 31 ±7 yrs and BMI 23 ±2kg.m-2. The mobility of the right diaphragmatic in supine was higher than in sitting position during QB (1.83±0.7 cm vs 1.37±0.54cm p=0.006) and DB (7.48±0.81 vs 5.17±1.48cm p<0.001) respectively (figure1). All individuals increased mobility in supine position, and it was approximately 36% at QB and 54% in DB higher than in sitting. Abdominal recruitment was not significantly different but the Sc was more active in supine (p= 0.07). Conclusions: In healthy subjects, diaphragmatic mobility is significantly influenced by body position and is higher in supine position. The active mechanisms still need further studies. ![Figure][1] [1]: pending:yes