For this exercise, you will again need the can of soup or a 1 liter of soda. Place a soup can or 1 liter of soda in your hand with palm facing downwards toward the floor. Support your forearm at the edge of a table or on your knee so that only your hand can move. Let the wrist down slowly go past parallel to almost 90 degrees with your forearm and then slowly come back up to parallel with the floor.
Tennis Elbow Exercises 2 – Forearm Pronation/Supination
For this exercise, I recommend you use a hammer, wrench, something that you can get a nice grip on. Once you have something in your hand with forearm supported by the arm of a chair, your knee or coffee table. Rotate hand to palm down position, return to start position (hammer perpendicular to floor), rotate to palm up position, repeat.
To increase or decrease the resistance, try moving your hand farther away or closer towards the head of the hammer. In other words, if you are grasping the hammer at the very end of the handle and the head of the hammer is the furthest away from your hand, then this will be the most challenging and greatest resistance for you
Tennis Elbow Exercises 3 – Finger Extension
Interweave a thick rubber band around all five fingers. Keeping your elbow as straight as possible [but if you feel pain when you completely straighten your arm only straighten as far as you can without pain], try to straighten and spread your fingers outwards as if you were going to catch a softball. Hold for three seconds, then let your fingers relax naturally; do not close your hand completely. For added resistance, use a second rubber band. Repeat for 25 repetitions for 3 sets.
Source White Market