The fact that knees limited range of motion on one plane can make them unstable and at risk of injury. Knee injuries may be caused by the heavy load they have to bear and the torque they can produce when in use. The mixture of bone, ligament, muscle and cartilage around the knee joint also allows for a variety of problems to occur. To help isolate and reduce knee pain, you may need to use anything from a compression sleeve to a full hinged brace.