I work in a rehab and sports medicine is one of our specialties. I also have had tennis elbow. There are many reasons why this can happen, both anatomical and mechanical. First step, see a sports med doc or orthopedic doc to determine what is causing the problem.
Usually however, the cause is overusing your forearm muscles which pull on the tendon attached to your Lateral Epicondyle, and the rubbing causes a tear to happen to the tendon or the muscle near the part where it attaches to the bone. This can be anatomical (Bone spurs or unusual bony prominences) but usually not.
So, to reduce the rubbing, you must reduce the amount of forearm muscle involvement.
1. Relax your grip - A lot of racket sport players find out that they are over-gripping their rackets. So, try reducing the intensity of your grip during game play. We should be relaxed more often anyways in TT and you may find this benefits your game anyway.
2. Reduce the weight of your equipment - Another thing you can do is to reduce the weight of your bat, or the head heaviness of your bat. Bring the center of gravity towards the handle. (See Der_Ecthe’s beast mod, but don’t go quite that heavy). You can also use weight tape Tennis and Golfers use.
3. Increasing the size of the handle for guys with big hands reduce the amount of grip pressure needed during game play. Usually smaller handles require more grip strength to be applied.
4. Adding grip tape, will add grip to the handle and reduce the need for you to over-grip (or feel like you need to over-grip). Also increases the size.
In addition to the above, if you ALREADY have symptoms:
RICE: Rest, Ice, Compress, Elevate.
NSAIDS such as Naproxen or Ibuprophen reduce pain and swelling.
Braces which fit over the forearm have been shown to help; there are special Tennis Elbow braces.
Physical therapy: This could be the best “CURE” of them all. Most people who play sports prone to overuse of one movement or another often have overdeveloped muscles in one part of their joint, but lack tone in opposing or accessory muscles which pulls things out of alignment. Re-aligning things might mean you need to develop other muscles which counter-balance the ERCP (The Muscle-tendon complex involved here). PTs and OTs can do this.
Start with visiting the right kind of doctor before starting any of the above to make sure this is indeed your issue, you never know, there are a million and one things which could be causing the pain, and it might not actually be “Tennis Elbow.”