After walking around for a few minutes, it is important to do some stretches. Lie on your back get into a comfortable position in which your upper back and neck are supported. Place a pillow under both knees, slowly lift one leg up, bending the knee slightly. Gently lower the leg. Repeat this exercise until you feel a slight burning sensation in your knee or the muscle above it, whichever comes first. Continue with the other leg in the same fashion. Be careful not to overdo this exercise since this could result in very sore thigh muscles and make walking painful. This knee exercise will result in stabilizing your knee by strengthening the muscle which will allow you to withstand longer periods of activity.