I have become somewhat thick-skinned after all the battles done in the name of RSI. My point was not so much that RSI can’t be in the lower extremities, but that once one has problems in upper extremities, the body has to compensate in places it would not normally compensate, and that eventually (not for everyone, but potential is there) leads to more problems in other parts of the body, which can be the lower limbs. I am sure the physiotherapists have a professional phrase for this, but I don’t know it. Fooled up body, it what I call it!
OK. Now about TMJ, Temperomandibular Joint Syndrome, thank you for your interest. I gather it is not all that well-known by the general public or GPs, it is more of a dental specialty! All your possible causes are in there – chewing, malocclusion (misalignment) of jaw/teeth, whiplashes, blow to head, etc. The website I use is http://www.tmj.org/site/ It’s worth looking at, with nice diagram on home page to show what’s happening. Chewing, talking, and so forth, if not a problem pre-TMJ, certainly are after you develop it. One of the first things I had to do was stop eating raw carrots, chocolate bars, etc., so I used to microwave my weekly Mars bar treat to just the right softness. There is something I won’t go without in the name of health.