Shifting into Left AF/IR and building strength in the left hip is the beginning of every PRI based lower body program. However, the concept of AF/IR can be confusing in the beginning. For those unfamiliar with the term, AF/IR stands for acetabular-femoral internal rotation. This describes the movement of your pelvis as it moves on top of your femur (leg bone). The acetabulum is your “hip socket”. As you walk, run, squat, lunge, or simply shift your weight to your left foot, the acetabulum has to move properly on top of the femur. It has to internally rotate. If the acetabulum does not move properly on the femur, you will not move correctly. In this respect, It’s not a matter of if you will hurt, it is a matter of when you will hurt. On the right side of your body, the acetabulum is moving into internal rotation on the femur all day long. Right AF/IR is easy to achieve (it’s actually being overdone). On the left side, it’s happening in a limited fashion or hardly at all. This is due to the way we are asymmetrically put together as humans. When you are new to PRI, sometimes you assume you have gotten your client to achieve AF/IR because you repositioned their left hemi-pelvis. This is not really the case. Simply repositioning a left pelvis is just the first step of achieving true Left AF/IR. Repositioning gives you the possibility, the potential, to achieve full Left AF/IR. It gives your acetabulum the position it requires to be able to move on the femur into internal rotation. So beyond repositioning a pelvis in the sagittal plane, attaining Left AF/IR involves restoring frontal and transverse plane movement of the pelvis and femur. As you work to get Left AF/IR you will often come across individuals who have very weak left hips. Securing that hip becomes a top priority. Fortunately, some of the same exercises that we use to restore frontal and transverse movements of the pelvis and femur are the same exercises you will use to begin to secure the left hip. The origins of a weak left hip are shown in the picture below.
In the first picture above, the pelvis is oriented to the right. The femur also orients to the right because it sits in the acetabulum. In this case, although the femur looks internally rotated, the femur is actually neutral in respect to the position of the pelvis. The femur is aligned with the direction of the pelvis. It only looks internally rotated because we are looking at a pelvis and leg that are facing to the right. In the second picture, the pelvis is oriented to the right, but the femur is externally rotated. It looks straight to us, but in relation to the pelvis, it is externally rotated. This is why simply looking at someone’s legs doesn’t tell us what their legs are doing. We generally can’t see that someone’s pelvis is oriented to the right, and that their leg is externally rotated. Everything looks straight to us. But strip off people’s skin and muscles, and this is what you would likely find. Only PRI testing tells us the true position of a pelvis and legs. What this means is that most people are walking around with at least a slightly externally rotated leg, and sometimes it’s so externally rotated that it creates left pelvic-femoral instability. This type of instability can manifest in different places all over the body.
Pathological Left Hip Weakness
Individuals whose testing indicates that they have lost the ligamental integrity of their anterior left hip, displaying ligamental laxity, have weak left hips. You know someone has lost ligamental support through PRI testing relationships. For example, take two theoretical tests. Normal human biomechanics may dictate that if theoretical test 1 is positive, theoretical test 2 should be negative. If you find that theoretical test 2 is also positive, this means something has gone wrong with the subjects body. Something had to occur outside of normal expected human biomechanics for Test 2 to be positive at the same time Test 1 is positive. One such relationship is that between the adduction drop test and the hip extension test. If someone’s adduction drop test is positive, meaning their leg can’t adduct due to an anteriorly rotated pelvis, they should not be able to extend completely. That is not a normal kinematic relationship. If someone has a positive adduction drop test, yet can extend their hip completely, they are considered in PRI to be “pathological”. In other words, if you find a positive adduction drop test, you should not find a negative extension drop test (you want a positive extension drop test). This is because if you can’t adduct your leg fully, you should not be able to extend your leg fully. If you can, your leg has done something funky to get that hip extension range of motion. Eventually we want both tests to be negative, but not until you can adduct your leg. When you can adduct fully, you should be able to extend fully. If you can’t adduct fully, you don’t want to be able to extend fully. If you can extend fully on a leg that can’t adduct fully, you’ve likely stretched out your hip ligaments to do it. So pathological describes an aspect of a pattern that goes beyond what is normal. In other words, a patho individual is someone whose body is doing something it shouldn’t be able to do when it is in the position that it is in. These pathological hips are the hips that you really have to work at securing. When you lose the ligamental integrity of the anterior hip, you find that the left leg is no longer sitting snugly inside the acetabulum. Due to the fact that the left hemi-pelvis, and thus the acetabulum, are oriented to the right, the left leg will often externally rotate back to the left in order to stay straight. Left hemi-pelvis is oriented right, left leg orients to the left as a compensation. This external rotation, coupled with the demands of an individuals normal life, the activities they participate in, the sports they play, stretching, all of these factors can contribute to someone loosening their ligaments. And once ligaments are loosened, there is no way to get them strong again without surgery. This is why it is often necessary to work a bit harder to secure the left hip, generally by really strengthening the anterior fibers of the left glute medius, the IC adductor, and the medial hamstrings. All three muscles will work together to position and hold the femur inside the acetabulum so that true Left AF/IR can occur and held during dynamic tasks. The video below explains a bit more about how a weak left hip occurs and the type of issues it can lead to. In this case I talk about left SI joint pain. But in reality, the consequences of left hip weakness can manifest themselves in various locations of your body.
Securing the Left Hip through True AF/IR
The first step in establishing Left AF/IR is re-positioning the pelvis in the sagittal plane. Generally, we use the left hamstring to pull the left pelvis posteriorly (backwards) from it’s previously anteriorly (forwardly) rotated position. If successful, the left adduction drop test will go negative. But you sometimes may find that although the left leg is now adducting more than it did before, it may not go down all the way to the surface upon which your client is lying, you may feel some restriction, or it may not be a smooth drop (for lack of a better way of explaining it) There are two main reasons this could be happening: First, you could have a tight posterior hip capsule. A tight posterior hip capsule will prevent the left femur from sitting snug is the acetabulum since it won’t allow posterior movement of the femur. Second, the left femur may have externally rotated itself out of a good acetabular/femoral position. It can also be a combination of both since they often occur together. Regardless, the next step is crucial to understanding what true Left AF/IR will feel and look like and what you need to see before a PRI program will work really well. You need to roll the head of the femur into the acetabulum. Just because you have repositioned a left hemi-pelvis, it doesn’t mean you have gotten true Left AF/IR. It was at Northeastern University in Boston during the Myokinematic Restoration seminar where James Anderson uttered this slogan that has stayed in mind ever since, and one I’d recommend everyone just starting out to learn well
"You Must Approximate Before You Can Rotate"
You must pull the femur back into the socket, approximate the femur and acetabulum, before you can start rotating the femur in the transverse plane. You have to bring them closer together. Many of the PRI exercises are designed to internally rotate the femur in a state of Left AF/IR. But before you can rotate the femur in Left AF/IR, you must be able to truly achieve Left AF/IR. If your adduction drop test is not smooth, or the femur is not adducting fully, my next thought is to approximate the femur into the acetabulum. Then restest. You may find that the femur now drops more smoothly and further than it did before.
Right Sidelying Left Adductor Pullback
The right sidelying adductor pullback is designed to “roll” the head of the femur into the acetabulum so that it fits snug and allow for good Acetabular-Femoral and Femoral-Acetabular movement. We do this by recruiting the ischiocondylar (IC) adductor. At the same time, if the left posterior hip capsule is tight, the “pullback” part of the exercise can stretch it so that it will now accept the head of the femur. There are times where this pullback is not enough and use of special posterior hip capsule stretching will be necessary.
Although I didn’t do it in the video since I didn’t have one on hand, you can place a small ball, a few inches in diameter, in between your feet. This is actually the way it is shown in the manual. It is not always necessary however. If done correctly, you’ll feel the exercise high up in the groin area of the left side. Be aware, it is not a comfortable feeling. Some people will experience some soreness the next day.
Hi. I am a sports therapist and have been very interested in reading you blog posts. I have a question though. It seems you focus on a left anterior rotated ilium. What happens if it is the right ilium that is rotated forward? Do you just do the exercises etc on the right side as prescribed for the left? Or do you have a different methodology?
PRI believes that due to the structure of the human body (organ placement, difference between left and right diaphragms, and neurological activity etc..) that, except under rare circumstances, the left ilium will always be rotated forward compared to the right. It’s not that the right side will never be rotated forward, but it will only be rotated forward if the left side is rotated forward also (again, except in rare circumstances).
I understand that there is another school of thought that identifies the right side as the side that is rotated forward, but I can’t recall the name nor can I recall why they believe that.
This left ilium rotated forward, which is the left AIC pattern, is demonstrated by the adduction drop test.
If the test is positive, meaning the leg will not adduct, it reflects a pelvis that is anteriorly rotated. I have tested hundreds of people at this point, and I’m yet to find someone who could adduct the left leg but not the right (which would indicate a right ilium rotated forward).
This is one of those things that people may be skeptical about initially, because it’s a pretty radical paradigm shift. But if you trust that the test is actually testing what PRI says it is testing, then you’ll see this pattern (left ilium rotated forward compared to the right) time after time.
Hope that helps,
You don’t mention how long lasting any improvement might be. Let’s suppose, for example, the adduction drop test is initially positive, but after the appropriate exercises, it then tests negative. When an hour later, or the next day, the adduction drop test is positive again, presumably the same exercises should be repeated until there is a negative result.
If that is correct – and it seems logical – how long might it be before more permanent change occurs – perhaps along the lines of each subsequent test being slightly less positive than before?
Generally, the adduction drop test goes negative relatively easily and in most cases will not go positive again, provided that the client does the home program at least a few times a week.
Some people will stay negative without doing the home program, but most will need to do it.
From my experience, the type of people who won’t stay negative at the pelvis (provided they are making an attempt at the home program) are people who have significant neck patterns that are influenced by teeth and vision issues, or people who may need orthotics for their shoes.
In regards to permanent change, it depends on the person. I’ve worked with people who initially I thought would be very challenging because they had lived with pain for many years, and they only needed one session. On the other hand, I’ve worked with people who seemed like simple cases turn out to be very complicated.
It’s important to remember that these extension patterns can be heavily influenced by the individual’s particular life circumstances and their life’s history. PRI is about much more than just bones and muscles, which is what you learn about as you progress into the more advanced seminar work.
Thanks for the explanation.
I first got interested in the PRI approach after reading a seven part article by Lisa Bartels. I tried following her recommendations but after some initial success the effect petered out. I think this may have been because I didn’t understand what you’re emphasising here: “You Must Approximate Before You Can Rotate”. In fact, the approximation exercise was the first one I abandoned as I had no notion of its importance and I wasn’t sure what I was doing with it. It was only when I read your article and also one called ‘Avoiding initial pitfalls’ by Jenifer Poulin and James Anderson that I realised I had rushed too far, too fast, and omitted a critical step.
Hopefully I will act in a more restrained fashion this time around. I live in Southern England and the nearest practitioner is 400 miles away.
I understand the feeling of isolation. It’s hard to figure it all out when you are on your own. Luckily I had the seminars I could take and ask questions. The “approximate before you rotate” concept was a huge leap forward in understanding why adduction drop tests could sometimes seem somewhat positive, but somewhat negative. Another factor is restriction in the thoracic area. Sometimes if people are tight in their right lateral chest wall, or mid-posterior back, you won’t get a smooth adduction drop, or you may have a hard time feeling the adductor pull-back correctly. There are so many variables!
I have been reading a lot about aic. I have a sacrum and spine that rotate right creating a functional short left leg so left ilium flares out and right goes towards left so that my weight is always on the left with a strong but externaly rotated left leg. The outer portion of the leg is very tight with weight in outer heal and right leg is weak and loose and mainly uses the inside part of foot gastroc inner hamstring and adductor magnus crying out. If I stand straight the legs want to turn left with right pelvis in front and right upper body leans back. But I usually bring it back to front and thus fall towards the left. Usually sitting in the left hip. Is this still a left aic? I have hypermobility. I feel like my body has unilateralized itself on the left side.
Do left aic still applies? For exemple my left femioral biceps is very strong and short.
Any posts on what to do with the right leg?
Thanks for clarifying.
I have this problem too. I have a left hip is posteriorly rotated so stand on my left leg mostly. My scrum sticks out on the left (faces left side bendt right). Itook me a long time to figure out this PRI stuff. I have a left on right Sacral torsion with a short left leg, I got confused on if I an in the left AIC pattern because of the posterior left hip and anterior right hip is opposite PRI. When I use my hamstring on the left side it reinforces the posterior illium and jams the Sacrum But the left leg is externally rotated still. My right adductor, handing and pelvic floor are super tight and the femur is internally rotated which matches the PRI model. So I follow the PRI instructions but be careful not to use too much hamstring on the left which pulls the illium even more posterior. Try to use mostly the adductor on the left. You sound like you are left aic but with a left posterior illium like me hence the short leg and why you stand on the left leg. PRI should help. This willI hope that helps.
I’m hypermobile. When I stand on both legs and relax everything my right heel pronates and my whole body turns to the right then the legs rotate me back to center so that my right leg pelvis and foot rotate left weight goes towards bid toe pronation in front of the heel like ready to continue and toe off towards the left with the axis of rotation on the left leg.
Left foot tries to supinate and end up with weight on right heel with no good contact at the big toe. So left foot turns a bit out after awhile but sometimes ends up with a stuck higher arch with less ability to pronate while walking.
My upper body does not turn right independently it is dragged back by the lower body so that my breathing is very easy on the right contrary to the pri model. The left ribs are very tight.
My sacrum sidebends left and turn right with l5 l4. Even if my right hip is high but pelvis to the left when back to center.
It’s like everything pivots on the left leg.
My pelvic floor is tight on the left. Left adductors are tighter on the left everything up and down is tighter on the left.
Regarding the Right Sidelying Left Adductor Pullback exercise: I am/was a PEC. I started pri with my pri trained PT in May 2019. I did this exercise early-on and thought I had it down. Yesterday, my PT wanted to introduce a more advanced exercise and we discovered I was not able to recruit my left anterior glute med in adduction, so she has returned me to practicing this exercise. Now, though I can really feel my left adductors working,(tight pinch in the left groin), I have no proprioception of my left glute med. In your post you mention that ‘there are times where this pullback is not enough’. That makes me think maybe you went through similar trouble yourself. Do you have any cues or suggestions for me to try for FEELING the anterior left glute med working while ADDUCTING my left femur? I am probably not attending to ALL of the details and am compensating. While my brain is working on this I thought I would ask you.