A system, apparatus, and method for motion monitoring. In an embodiment, a plurality of self-powered active Radio Frequency Identification (RFID) transmitters are each configured to intermittently transmit radio frequency pulse at a rate proportional to motion, containing identification information. The pulse produced by each of the RFID transmitters are received and analyzed at a receiver. The analysis results in the identification of pattern of activity, which is used to produce meaningful data regarding the motion of a user. The RFID transmitters may be provided on a wearable tag.