<prompt> Tennis elbow is characterized byTenderness over the medial epicondyleTendinits of common extensor originTendinitis of common flexor originPainful flexion and extension  <response>: Tennis elbow is extraaicular affection characterized by pain and acute tenderness at the origin of the extensor muscles of the forearm from the lateral epicondyleIt is believed to be caused by strain of the forearm extensor muscles, paicularly the extensor carpi radialisbrevis, at the point of their origin from lateral epicondyleRefer: Mohindras Fundamentals of Ohopedics, 2nd edition, pg no. 175, 497 