The tendon usually involved in tennis elbow is called the Extensor Carpi Radialis Brevis (ECRB).
The ECRB muscle helps stabilize the wrist when the elbow is straight.
Ask the patient to straighten the arm at the elbow and then perform resisted long finger extension. This will stress the ECRB and reproduce the pain. One can also ask the patient to lift the top of a chair in the air with the elbow extended.
