Re: Chronic Joint/Tendon Damage
I haven't bothered to look into joints and genetics before posting this, but I think it is instructive to note that in general medical science is moving toward identifying more and more genetic contributions to disease. I suspect joint degeneration and the likelihood of sustaining an acute joint injury from a particular motion (rather than just putting stress on the joint) are two areas where there might be a lot of genetics involved.
It is worth searching GoogleScholar or PubMed to look for studies on genetics and joint injury. If you find any genetic identifiers in the literature, you can get analyzed at a company like 23andMe, download their raw data file, and find out if you run a higher risk of injury. You'll have to figure out the details of that from someone else, though.