FBI: A Mechanical Abutment

We're going to be focusing a bit more on FBI so if you could give a quick synopsis just for any of the listeners that whether they're not familiar with the term or maybe they've heard about it but not entirely sure what it is. The concept has been around for a long time and it really got notoriety about in 2003 when I was a young man who was since passed on this very eloquent paper. So kind of expanding on that, how is our understanding of F.A.I. or impingement evolved from kind of the beginning to more so now like our understanding because as you mentioned, maybe people are more short than originally thought.