A method and device (10) are provided for monitoring regular movement of a human body (34), such as an infant's body. The method includes attaching the device (10) to the body (34) with a protuberance (24) of the body in abutment with the body, so that the protuberance is deflected as the body moves regularly. The deflection of the protuberance (24) is monitored and an alarm (18,19,20,52) is activated if the pattern of deflection of the protuberance changes to a predetermined extent, e.g. if it is disrupted.