every year it seems we have someone go down with that injury
I wouldn't be surprised at all if most every team does. It should be a fairly common injury given the nature of things. Just think about trying to stop/tackle a 220+ pound individual running past you and you're trying to reach out to slow/stop them. It's all well and good if you can kinda get in front of them, but if they're even just six inches off your hip and running by and you have to reach out, that is a MASSIVE strain on the shoulder, bicep, and pecs. I think if you look back at our history of this injury is is primarily Linemen (O & D) and Linebackers, and that makes total sense.