In spending much of my free time around the gym, I’ve seen lots and I try to pay attention. The things I’ve noticed is that injury correlates strongly to inflexibility. In other words, the people with the broadest range of motion become injured the least often.
It happened to me: I have very flexible shoulders and my upper body is never injured — and
I put them through a lot. My worst joint is my right ankle. Wonder which knee gives me problems? Yup, the right one. I see this same pattern continue with knee, wrist, ankle or elbow problems. All about flexibility. The least injured hard-charger I know is also the most flexible.
Like much of exercise science, we have little statistical facts to validate my hypothesis. But, watch your friends and see who is getting hurt. Flexibility is likely a huge problem for them. So, give them a hug, piece of gum and a groupon for some cheap yoga classes.