Stress tendonitis on the lateral epicondyle.
Condition where pain is experienced and tenderness is elicited on the lateral aspect of the elbow as a result of inflammation at the site of common extensor tendon insertion
is caused by physical strain through any one of a number of activities. The medical name for tennis elbow is 'lateral epicondylitis' (the lateral epicondyle is the bony part that is on the outside of the elbow joint). It is caused when the tendons coming from the muscle of the forearm become inflamed at the point where they join causing pain and tenderness. Further info.