Are you suffering from back or knee pain? This is a common condition, and there is much reason why do Knee pain occurs. Here are some causes of pain behind the knee, when to seek help, and how to care for your knee at home.ack knee persons have different causes. Some of the leading causes of knee pain include strains and pulls of the muscles of the knee. This can cause pain in various areas of the knee, such as the back of your knee.