These sound like my symptoms - tendinitis/tendinosis in knees, elbows, hands, hips, and sometimes shoulders, and one of my ankles even got into the act at one point. Plus I dislocated both kneecaps within a three-month period, and also have some muscle cramps but I don't know if that's related. It all started about two years ago, and I'm 31 now.
I've also been to lots of doctors and had lots of tests but they keep coming back negative. Has anyone gotten a diagnosis for anything like this at all? It just seems like the connective tissue is weakened and/or not healing well, but no one seems to have any ideas why this might be the case. Meems, your ideas sound like possibilities for sure - but are there other conditions that could cause this as well?
Also, has anyone found any meds, exercises or other therapies that have helped treat this kind of pain? I am trying to keep in shape but my physical therapist keeps telling me to stop doing whatever it is I'm doing (biking, strengthening, swimming, etc.) as soon as I start getting substantial pain. I'm getting ultrasound therapy for my elbows right now and kinesiotaping the heck out of them but I don't think that's helping.
Also, meems, I might lay off the naproxen if I were you. I had about a 6-month period of really bad pain flareups, and in retrospect I think the severity might have been due to doping myself up with high doses of naproxen. When I found out that naproxen interferes with collagen deposition (and hence healing) I went off it, and though the pain continued the episodes after that were not as severe. Anyhow, it's just an idea.