Basic principle of exercise....you have to do the moving, not a machine move you to benefit. Muscles only get stronger when they are used. Same with bones...they need weight bearing exercise. You can do simple exercises on stairs, marching in place, something called hindu squats. Best idea is to ask for a doctor's order for PT and have a professional work with you and give you a simple home program that addresses your specific needs.
A comprehensive program would involve some mild cardio, light resistance or weights, range of motion and stretching.