Shoulder
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.
Knee
The medial collateral ligament (MCL) on the inner side of the knee is most often torn when there is a force that strikes the outside of the knee. The MCL attempts to resist widening of the joint and tears if the force is too great.