<prompt> Tennis elbow, is characterized by -Tenderness over the medial epicondyleTendinits of common extensor originTendinitis of common flexor originPainful flexion and extension  <response>: Tennis elbow is extraarticular affection characterized by pain and acute tenderness at the origin of the extensor muscles of the forearm from the lateral epicondyle.It is believed to be caused by a strain of the forearm extensor muscles, particularly the extensor carpi radialis brevis, at the point of their origin from lateral epicondyle. 