<qa>  What is the OAK device based on?The OAK device is a technologic system, based on virtual reality. It allows to quickly perform a fall risk assessment integrating clinical indexes of the Brief-BESTest The Balance Evaluation System Test, and kinematic and posturgraphic indexes. The participants interact with the OAK device through simple exercises, then the device provides an assessment of their functional mobility, equilibrium and postural reactions. 