If something causes pain, it is a sign that you are doing damage to that area. Stopping the activity and giving the area time to heal is essential and may be enough to resolve the problem.
With knee joints that already have some damage, the weight of walking and performing other daily activities puts pressure on the bones surrounding the joint. This pressure causes damage and changes to the bones called bone bruising and results in pain. If you remove the weight and pressure from the bones, they can begin to heal and the pain decreases.
In order to remove the pressure from the bones, it is necessary to use a crutch, cane, or wheelchair for a period of time to lessen your body weight on the joint. This is not done permanently, but for a few weeks or months depending on the severity of the problem. During this period of reduced weightbearing, the damage to the bones will stop and healing can begin. This in turn will reduce the pain.