A mobility assistance apparatus and a method for improving the mobility of a person using a walking aid, such as a cane, crutch, or walker, involve use of a device for ground engagement with ambulating using the walking aid. In a preferred example the device is a resilient lower extremity prosthesis that is capable of storing and releasing energy to generate propulsive force to aid mobility. The prosthesis has a foot, ankle and shank. The shank has a lower portion that is anterior facing convexly curved for generating forward propulsion with ambulating to aid mobility.