Innominate Rotations

00:00 So, let’s take a closer look at innominate rotations. The entire innominate bone will rotate either anteriorly or posteriorly in comparison to the sacrum. So, one of the things that I like to do is to use my hands as models for the innominates. So, what I usually do is to kind of create my finger like this. I use my thumbs to represent the PSIS, my pointer finger to represent the ASIS and my pinkies to represent the pubic tubercles and so you'll kind of have your own pelvic model in your hand when you're trying to answer exam questions. And so when you have a posteriorly rotated innominate, the innominate is rotated or kind of like being pulled by the posterior leg muscles, probably the hamstrings, and this kind of pulls the innominate posteriorly. Usually, there is a stretching of the anterior leg muscles and then when there is anteriorly rotated innominate, the innominate is usually being pulled by the anterior leg muscles, usually the quadriceps, and so the attachments of the quadriceps, the ASIS, the AIIS and as it pulls forward it causes anterior rotation. This will cause a stretch in the posterior leg, sometimes patients will complain of posterior leg pain. So, here is an example where we have a left anteriorly rotated innominate, you have a positive standing flexion test on the left side, your ASIS is going to be more inferior on the left side, your PSIS is going to be more superior on the left side and your pubic tubercle might be a little bit more inferior or equal and the medial malleolus is actually be more inferior. So, to think about what happens at the innominate that affects leg length. So if I anteriorly rotate the innominate, if you think about the acetabulum, the acetabulum will become more inferior if I anteriorly rotate. So, with the anterior innominate rotation if the acetabulum is rotating and becoming more inferior, that is going to make the medial malleolus and the leg length in general appear more inferior on that side. So again, anteriorly rotated innominates, patients may complain about hamstring tightness because you are rotating the innominate on that side pulling on the posterior leg muscles. Sometimes you might have sciatica, a shooting pain down due to piriformis issues. You might have some iliolumbar ligament tenderness. Again, if I'm rotating anteriorly that is going to pull on some of those ligaments in the posterior aspect, you're going to have a freedom of anterior rotation when you're doing motion testing and there's a restriction to posterior rotation with motion testing. This is an example of the opposite. So we have a left posteriorly rotated innominate. Here, you're going to have the standing flexion test again positive on the left, you're going to have your ASIS now. Since it's posteriorly rotated, the ASIS is going to be superior on that side and the PSIS is now going to be inferior. Your pubic tubercle will be a little superior equal and the medial malleoli will be driven superiorly because the acetabulum is driven up. So, posteriorly rotated innominates, your patients may complain about groin pain secondary to the rectus femoris pull, you might also have knee pain secondary to sartorius dysfunctions, you may have some inguinal tenderness when you're palpating and then you're going to have a freedom of posterior rotation when your motion testing and restriction to anterior rotation. So, let’s practice some of this information in the item here. So, here we have listed the findings of our physical exam, you have a standing flexion test that is positive on the right, the ASIS is superior on the right, the PSIS is superior on the left, the pubic tubercles are even and the medial malleolus is superior on the right side. What is our somatic dysfunction? So, let’s use our hand models to try to work through this problem. Given that you have a standing flexion test that is positive on the right, your dysfunction is going to be on the right side and once you have the side of dysfunction you want to name all the other findings according to the right side. Item writer will sometimes throw in findings on the left side to try to confuse you. So here, the ASIS is superior on the right, the PSIS is superior on the left which means that the PSIS is inferior on the right. The pubic tubercles are even and the medial malleolus is a little bit more superior on the right. So, this falls in line with a right posterior innominate rotation and because the innominate is posteriorly rotated that is going to bring the acetabulum a little bit more superior confirming the findings of the medial malleolus.