Hi, have a look at this video. It might help you help yourself. Let me know if it does, or if it is another part of the elbow forearm.
Did you mean to post a link? I'd be willing to bet anything that the poster is using arm pressures on each individual note. My most recent blog post on keybedding explains the basic reasons why problems occur when playing this way.
Arm pressure done correctly (the Russian School of Piano Technique) is how i play and i have be fine for years. It's tension that is the problem, not arm weight.
The first thing I would consider is tension. Is your right arm more tense than it should be? Secondly, I would check if your elbow is sitting at a weird angle. Freeze every once in a while while playing and see if you are doing something weird with your posture.
Hey, that's a good idea, then he could strengthen the problem until it becomes permanent!