Bill Hartman 25:50–28:16
What we want to do is look at the measures Jason took and start by reconstructing the pelvis because the pelvis representation is a little easier to see than in the thorax, but we'll try to give you an example of what this actually looks like. So let me grab the pelvis for a sec. Again, this is a guy with left shoulder pain that's been diagnosed as an impingement, but we've got some pelvis measures which are great because our iterations give us confirmations of positions. Like I said, it's a little easier to see in the pelvis. When in doubt, we're going to start with the basic foundation. So Jason says that this guy is a narrow ISA. So right away, we know we're going to see a representation that's going to start to externally rotate these. We're going to start to counter-nutrate this sacrum. He throws us some information on the left side. We've got left hip ER at 60 degrees and IR at 20 degrees on this side. So remember when we're talking about narrow ISAs that we're always going to be biased back towards an ER position. So we're going to have more ER than IR. If we have full excursion to hip under those circumstances, we're going to have about 100 degrees of total excursion. So right away when we start seeing 60 degrees of ER, 20 degrees of IR, we know we're in a deficit. And so we probably have some measure of loss of that extra rotation that we would naturally gain from just being a narrow ISA. So we're going to start thinking that, oh, we've got an anterior orientation going on here. Now if we flip over to the other side, we go to the right hip and we get 45 degrees of ER, 45 degrees of IR. So now what that's going to tell us again, we've got an anterior orientation, but we've got a lot more going on the right side. So right now we got to start thinking like, okay, I'm on this oblique axis because I've got a greater loss of ER here. If I've got 40 degrees of internal rotation under these circumstances, I got a pretty decent tilt here because the only way that I'm going to pick up 45 degrees of IR under the circumstances to get the acetabulum facing down. So I've got a situation that looks like this. And actually, if we want to get really technical, watch this close, it's going to look kind of like that. That's more like what we're going to see with this type of a right oblique axis, where you're going to see sort of like an elevation of this ilium. The reason I bring this up is because what it's going to look like in the thorax is going to be very similar. So it's going to look kind of like that.
pelvis reconstructionhip rotation assessmentoblique axis tiltnarrow ISAsacral counter-nutation