Tendons are not a part of the vascular system, so blood doesn't flow through them, which means that the all-repairing white blood cells can't get in there to do their jobs. Tendons only heal when they are not used for an extensive period of time. I injured my peronius brevis tendon in my foot almost a year ago now: This month, due to wearing an immobilizing boot for close to a month, special ankle braces for two months or so, and reducing my walking and exercising, I now only have moments of pain, instead of constant pain. It sucks. And it will continue to suck as long as you continue to use the arm. However, acupuncture (and light massage) will work wonders on it. Especially RSI. Go to acupuncture 3x a week for two weeks, and you will feel significantly better, if you have also basically immobilized the arm to let it heal.