Do tennis elbow and a hyperextended elbow feel differently?

Yes: Tennis elbow will be painful on the lateral (or outside/away from the middle of the body) aspect of the elbow and when you resist wrist extension it accentuates the pain. An elbow hyperextension hurts all over the elbow and particularly in the back. Also, hyperextension injuries result from acute injuries where tennis elbow symptoms generally occur with repetitive trauma.

Yes: Normally tennis elbow is painful at or near the bony prominence at the outside (lateral) part of the elbow, known as the lateral epicondyle. Tennis elbow pain is often exacerbated by lifting items, especially in a palm-down position. A hyperextended elbow normally causes generalized or anterior elbow pain from a traumatic event and can be worsened by repeating the hyperextension moment.