Tennis elbow is the name for a certain pain on the outside of the elbow. The pain occurs at the bony lump on the outside of the elbow, just above the joint. People who have never played tennis may develop this condition.
Sudden or repeated stress can cause tiny tears in certain muscles and ligaments at the point where they attach to the outside part of the elbow. These are the muscles that straighten the wrist and fingers when they are bent. These muscles also rotate the forearm so that the palm faces up. Tennis elbow causes pain when these muscles are used, or when the outside area of the elbow is bumped.
Tennis elbow can be caused by a sudden tension on the muscle or ligament where it attaches to the outside of the elbow. Often this happens during a backhand stroke in racket sports, especially if the stroke technique is poor. Another cause is overuse of the muscles in a repetitive way. Examples of this are prolonged use of a screwdriver or typing.