Exercises to strengthen the knees

5. Calf Raises

Stand facing the back of a sturdy chair, other support such as the back of a couch, or a wall bar at the gym. You can also do this on the stairs, holding on to the banister with your heels hanging off the edge of the step. Slowly raise the heels as high as you can, then lower. Do three sets of 10-15. When it becomes easy, lift one foot slightly off the floor, with all your weight on the other foot.