How Knowing Who, Where and When Can Change Health Care Delivery every 0.4 sec. However, it is possible to estimate tag location more than ten times per sec, thereby making it possible to track movements more precisely. Accordingly, we are currently compar- ing this technology against other conventional methods and equipment used to assess gait and balance. If comparable results occur, the equip- ment used to monitor everyday movements of residents in congregate living settings could also serve to perform the standard gait and balance assessments. It is possible to monitor the movements of large numbers of people simultaneously using ultra-wideband RFID technology. This creates op- portunities to study the locations and time course of interactions among residents in congregate living situations. If staff in the congregate living settings also wear transponders further opportuni- ties are created for studying the location and time course of interactions between staff and residents, CONCLUSION In this chapter we have presented arguments and research to show how movement information can provide valuable insights into disorders and can broaden our understanding of their pathogenesis. We have focused not so much upon the gross amount of movement as we have the structure of the movement itself. By differentiating random from well ordered movement components we find significant relationships between spatial variability and disease that complements relation- ships observed between temporal variability and disease by other researchers such as Hausdorff and Verghese. The study of movement variability using sensor networks may provide fertile ground for the study of Diabetes Mellitus and other dis- orders which have movement changes as part of their symptomatology. Finally the study of movement variability