An example posture monitor embodiment includes a first angle sensor coupled to an upper plate and a second angle sensor coupled to a lower plate rotatably connected to the upper plate. The posture monitor may be coupled to a persons chest and to the persons abdomen below the waist to measure an angle related to the persons posture. The posture monitor may activate an alarm indicator when the measured angle changes by more than a preferred threshold value, indicating a change in the persons posture.
