3DUIs are becoming very popular among researchers, developers and users as they allow more immersive and interactive experiences by taking advantage of the human dexterity. The features offered by these interfaces outside the gaming environment, have allowed the development of applications in the medical area by enhancing the user experience and aiding the therapy process in controlled and monitored environments. Using mainstream videogame 3DUIs based on inertial and image sensors available in the market, this work presents the development of a virtual environment and its navigation through lower member captured gestures for assisting motion during therapy.