A method and system of simultaneously monitoring body position and respiration of a subject are provided. The end-expiratory value of an axial dimension of a distance Xi between a first location and a second location is monitored for the subject orientation, and is then assigned a body position for the subject orientation during a calibration maneuver in which the subject is asked to assume various body positions. The transient voltage spikes in Xi voltage are measured to determine when the subject orientation changes. Following the subject orientation change, the stable end-expiratory voltage is determined to define a new body position. The new body position is outputted to a data output interface communicating with varied output devices.