Stroke is a leading cause of long-term impairment, causing a fatality if not act upon in time. Home-based post-stroke rehabilitation plays an important role in helping patients to regain normal mobility and functionality at their residence. However, existing home-based rehabilitation approaches fail to effectively motivate patients on frequent engagement with exercise to achieve the intended outcome. In this paper, we develop VRInsole, a synthetical solution combining a Smart Insole footwear sensor and virtual reality (VR), targeting lower extremity mobility training in an immersive environment for stroke rehabilitation. Specifically, the motion information collected from the Smart Insole serve as the input for the VR to perform corresponding exercise animations. To prove the feasibility of VRInsole, an experiment is conducted on the recognition of lower extremity motion direction, which achieves an average accuracy of 93.9%.