<qa>  What is the OAK device?Participants are recruited at IRCCS Galeazzi Orthopedic Hospital in Milan, among outpatients and healthy volunteers. A brief questionnaire is administered in order to collect data relevant to the CDC Algorithm for Fall Risk Assessment. Then, participants are assessed through the OAK device. The OAK assessment is evaluated in terms of performance, accuracy in comparison to the CDC Algorithm for Fall Risk Assessment and safety. 