Shoulder impingement, which people sometimes call swimmer's shoulder, is a condition that causes pain in the shoulder due to a tendon or bursa rubbing against the shoulder blade.
Medical News Today
Knee joints are under a lot of physical stress each day. It is very common to experience pain in one or both knees due to normal wear and tear, physical activity, or injury. Often, if a person has a knee injury or strain, the pain can feel as though it is burning.