An electrogoniometer is a device that once properly placed on a joint is able to measure the angle. In the laboratory there are two bi-axial goniometers compatible to the auxiliary channels of the Porti™ device. Footswitches are sensors which, properly placed under the sole, detect the principal gait phases (swing and stance phase for each leg). The signal coming from the footswitches is acquired with the PortiTM system.