The foot and ankle can affect knee pain. If the foot is overly flat or pronated, this contributes to internal rotation of the lower leg and knee. In my experience, 85 percent of the people with knee pain benefit more from strengthening hip muscles rather than using foot orthoses (shoe inserts) to affect the knee.
A history of ankle sprains can also affect knee pain. This happens as a result of protecting the ankle or if the ankle lacks range of motion. The knee then often makes up for this lack of motion, causing pain.