Speaker A
Skill number two is shifting into left AFIR. Now, AFIR means acetabulum. This is where the leg—here's my leg—fits into the pelvis on the left side. That is the left acetabulum. So that AF
Learn how to shift into left AFIR to improve hip stability and gait by Neal Hallinan in this detailed PRI tutorial.
Ask about this video. Answers come from its transcript only — with the timestamp, so you can check them.
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Key Takeaways
- Left AFIR is crucial for proper hip function and weight transfer during gait.
- Many people have biomechanical patterns that prevent effective left AFIR, causing hip weakness and compensations.
- Unloading the right side and activating specific muscles like the hamstring, adductors, and glute medius are key to shifting into left AFIR.
- Restoring left AFIR improves pelvic and rib cage alignment and overall movement efficiency.
- PRI exercises target these biomechanical corrections to help people achieve better hip stability and gait.
What the video covers
- Left AFIR stands for left acetabulum femur internal rotation, a key movement where the pelvis and femur internally rotate simultaneously on the left side.
- Proper left AFIR is essential for effective weight shifting onto the left leg during walking and athletic movements.
- Many people have a pelvis oriented to the right and a left femur externally rotated, causing compensations and weakness in the left hip.
- Chronic external rotation can stretch and weaken ligaments and the front hip capsule, leading to instability and poor hip function.
- Skill one involves unloading the right side and driving the pelvis left to prepare for left AFIR.
- Heel strike initiates hamstring activation that pulls the pelvis back into left AFIR, with adductors and gluteus medius stabilizing the femur internally.
- Proper left AFIR aligns the pelvis, rib cage, and upper body in a coordinated pattern essential for efficient gait and athletic performance.
- Humans tend to favor the right side neurologically and biomechanically, making left AFIR challenging but critical to develop.
- Without left AFIR, weight may be placed on the left leg but the body remains in a right stance pattern, limiting true left leg loading.
- PRI exercises focus on restoring left pelvis position and internal rotation of the left femur to achieve and maintain left AFIR.
Chapters
- 00:00Introduction to Left AFIR
- 00:40Internal Rotation Mechanics of Left AFIR
- 01:16Compensations in Pelvis and Femur Positioning
- 01:45Ligament and Hip Capsule Weakness from External Rotation
- 02:20Testing Hip Weakness and Effects of Chronic Patterns
- 02:46Unloading Right Side to Enable Left AFIR
- 03:47Heel Strike and Muscle Activation for Left AFIR
- 04:18Muscle Coordination and Pelvic-Rib Cage Alignment
- 05:18Neurological Preference for Right Side and Challenges
- 05:43Case Example and Importance of True Left Leg Loading
Full Transcript — Download SRT & Markdown
Speaker A
This is femur. So acetabulum on femur. Okay, left AFIR. IR is internal rotation. So what this means is the acetabulum, this left side of the pelvis, needs to internally rotate. So this is the—this is the inner side of the femur that has to
Speaker A
rotate towards the inside of the femur. So it's internally rotating on the femur. At the same time, the left leg, the left femur, my eyeglass case, internally rotates on the acetabulum. These should happen pretty much simultaneously when we put our weight on the left foot. That
Speaker A
does not happen when you're in a pattern. When you are on the left AI see pattern, your pelvis is oriented to the right and your femur is externally rotated to the left. Get excellent rotates in order to
Speaker A
stay straight. If we didn't have to walk, we wouldn't have to compensate, but because we're in a pattern where the pelvis is oriented to the right and the femur, instead of staying oriented to the right, turns out in order to stay
Speaker A
straight so we can walk forward. Otherwise, we would be blocking diagonally. Now, when this left leg externally rotates and it stays there for too long, and maybe this is going on for years and years and years, and maybe
Speaker A
you need even more external for whatever you're trying to do, and the pelvis is still stuck to the right, what's going to happen is the ligaments that attach from the front of the pelvis, from the acetabular area to
Speaker A
the femur that check external rotation, that prevents too much external rotation from occurring, they can get stretched out. And when they get stretched out, they get weakened, and the whole hip joint in the front, the whole left side is weak, and you can feel it. In
Speaker A
a lot of people, their leg, you know, you're testing them, you'll—I'm on their side, you bring them back for the adduction drop test, and it's just—there's no—there's no tension in that hip there. The rest of their bodies tense
Speaker A
and they're in pain, but this hip is so weak, the leg is just flopping, and you really have to stabilize that joint to then bring the leg down. So left AFIR has not occurred for these people for a long, long, long, long time.
Speaker A
And in fact, because of that, the front of their hip capsule is usually stretched out. I would say most people have, especially if they're remotely athletic, most people have stretched out hip capsules in the front on the left side
Speaker A
because of this issue. So skill number two is having the ability to effectively shift into your left hip or into left AFIR. So skill number one, make sure you watch that video, was get off your right side, drive your pelvis towards the
Speaker A
left. You're gonna need a right arch and a right glute to do that. If you can't unload your right side, you can't get to the left. If you can effectively unload the right side, at that point your pelvis
Speaker A
should orient to the left. Now you're switching into left AFIR. Heel strike, this pelvis should start to orient—who actually, before the heel strike, this pelvis will already start to orient towards the left. Heel strike, it
Speaker A
should happen even more. Heel strike gets the hamstring kicked in. The hamstring attaches to the pelvis, starts to pull. At this point, the pelvis is still forward on the left, it's orienting to the left, and then the hamstring kicks and it
Speaker A
starts to pull that pelvis back in, and that is what provides left AFIR. It is that hamstring pulling the pelvis back on the left as you make heel strike. And then the left adductor and medius have to kick in to internally
Speaker A
rotate the left—the left femur into rotation on the pelvis itself. Once your arch comes down, heel strike arch, that's where most PRI exercises are getting you to, and you'll have a flat foot, you'll have a brain
Speaker A
that's sensing that, that is sensing the ground through a medial arch on a pelvis that is neutral or in left AFIR. Again, adductor, glute medius, anterior lupitas are stabilizing the pelvis. You'll have your left COA, so this
Speaker A
rib cage, so here it goes to the left, you're in left AFIR, the rib cage orients to the left side, bends to the left in the frontal plane, and then up top starts to counter rotate back to the
Speaker A
right, and your left arm starts to come through. And that is left stance, and that is what PRI is really trying to get you to, to be able to stabilize. And we are challenged because humans prefer the
Speaker A
right. We got more muscle over there, we have that bigger right diaphragm neurologically, we just like to use the right side better. We're always reaching with our right arm. There's a lot of reasons that 90% of the world is
Speaker A
right-handed. We are righties, whether you're lefty or righty, you're righty. Okay? So the ability to shift into left AFIR requires, and then stabilize—and I'm not even going to say stabilize, that's probably a different skill—just getting left AFIR. People
Speaker A
get stuck there on the right leg. They're coming through, their heel hits the ground, and I'm working with a golfer right now, and he knows he cannot shift into his left hip. He could describe it, but he had no clue what was going on. He
Speaker A
would get here, and when the pelvis was supposed to move back on the left after he's exiting his right foot, his left foot makes contact with the ground, this left pelvis would never shift back. So his pelvis would never orient to the
Speaker A
left, so he could never actually get into left AFIR. So he's still stuck on his right side, even when his weight is pretty much on the left side. Biomechanically, his weight is not on the left side. He's not really on his left
Speaker A
foot until he can get AFIR. If you can't get that biomechanically, you're still kind of—you still got that left leg a little externally rotated and a pelvis that is still kind of oriented to the right. So
Speaker A
you're not truly on your left leg, even when your weight is on your left leg. You're still exhibiting right stance. And in fact, you'll see a lot of people putting weight on their left leg and their upper body is still over to the
Speaker A
right. So skill number two is shifting into left AFIR, or better yet, I'll say exiting right stance at that transition zone, getting into left AFIR. And that is skill number two, and that's what most of the most basic PRI
Speaker A
exercises are trying to get you to do by restoring proper position of that left pelvis by bringing it back, reorienting the pelvis to the left, and then internally, internally rotating the left leg on that pelvis. If you found this
Speaker A
video interesting or helpful, could you please like it, share it, subscribe to the channel, do anything you can to spread this information because PRI is really changing people's lives, and I hope to share it with even more people. Thanks.
Topics:left AFIRacetabulum femur internal rotationPRIpelvic rotationhip stabilitygait mechanicsleft hip internal rotationweight shifthamstring activationpelvic alignment
