I have golfers elbow (I don’t play golf).
Most of the time golfers elbow is onset through repeated lazy ways of opening doors and picking things up, letting the elbow joint take the weight of things rather than letting the muscles (especially the back muscles when pulling things) do the work.
I know for golfers elbow, strengthening the forearm muscles and biceps has made my symptoms of pain on the inside of my elbow joint almost disappear. Also making sure back posture is good and pulling with the back muscles rather than the lazy way I used to just pull with the arm, has made it better.
At a guess, I presume tennis elbow, being on the other side of the elbow joint, may be onset through lazy ways of pushing things?
Maybe strengthening of the forearm muscles and the triceps will alleviate the tennis elbow pain, as well as proper posture when pushing things and using the chest muscles properly?