Introduction:
To examine the stability of breathing pattern in healthy adults, in sitting and supine positions. An observational single group repeated measures design.

Methods:
Thirty-eight healthy adults (age 31.08 ± 6.56 years) with no reported history of respiratory disease. Resting breathing patterns were recorded over 15-minute periods in sitting and supine using respiratory inductive plethysmography (RIP). For each position comparisons were made: within individual recording sessions, between recording sessions on a single day and between recording sessions on different days. Eight breathing parameters were extracted from raw RIP data: inspiration and expiration time, breathing cycle time, respiratory rate, and the regional percentage contributions of ribcage and abdomen during inspiration and expiration.

Results:
For nearly all parameters across all comparisons in both positions there were: strong correlations, low to moderate within subject standard deviation values, and narrow 95% limits of agreement, with Bland and Altman analysis indicating good agreement. There were no statistically significant differences in cohort mean values.

Conclusions:
Recording breathing patterns in sitting may be a useful alternative to the supine position. Ribcage and abdominal contributions to respiratory movement have sufficient stability to have value as a potential outcome measure for evaluating physiotherapy interventions.