I am so tired of hearing that term especially when it comes to Barkley and Jones. The term suggests that there is something wrong physically or structurally with a persons body. Having chronic issues with a shoulder, a hamstring, etc that are prone to recurring issues is what it means. It doesn't mean just plain bad luck. Barkley stepping on an opponents foot and spraining his ankle. Jones getting hit in the helmet with another helmet isn't "injury prone".
There is a difference between "injury prone" and some bad luck.