It's very common when people start doing a new exercise regimen. Muscles can become significantly stronger on a timescale of months, while an equivalent increase in the strength of tendons happens on a timescale of a few years. Once somebody has a few years of training under their belt, muscle mass gains are way slower and the capacity of the ligaments will have caught up and these issues go away. However, with bodybuilders and strength athletes these problems can easily come back once anabolic steroids are involved and give big muscular gains without the same level of adaptations in connective tissues.
I don't doubt it. You make casual friends sometimes at certain gyms, especially if any sort of sports are involved like tennis or even group classes.
I am a super introvert and know at least half a dozen folks with such issues, more if you include my close friend group.
Any place that has a lot of physically active people stressing their limits a bit is going to have a lot of injured folks over a decent period of time. And of course it gets talked about quite a lot, since it limits performance and ability.
My trainer knows I have a chronic shoulder issue, and an adductor issue at the moment I'm working through that we need to avoid stressing too much. The few other folks who tend to work out around my schedule know of this, and I know of theirs.
