On structural adaptation limitations (of the hip)

(Last Updated On: May 20, 2017)

One of the most repeated questions I’ve received the last couple of years deals with wanting to change human structure. This has been primarily related to hip retroversion, due to a post of mine on the topic.

Despite my efforts, the point of hip retroversion being a structural “issue” hasn’t hit home for many. In that it’s like height, you can’t really change it.

Now, I’ve been very careful to not say, “You can’t change bone.” Or “You can’t change your structure.” I’ve seen others say this, and that statement is wrong. Bone, as well as practically everything in the human body, has an incredible ability to adapt. It can take FOREVER, but it can do it.

One example I’ve used before is if the fibula is removed from one leg, the tibia will adapt to be the size of the tibia and fibula on the other leg. Not only can bone change, it can change dramatically, and specifically.

-> I discuss the above photos in more detail in this post. The above changes took 3.5 years to happen! Part of this may be because the changes were in kids undergoing cancer treatment. But kids also lay down new bone much faster than adults. Say the kids didn’t have cancer, how much faster would this really happen? Even if it only took a year, that’s a long time.

Not all things can be changed though. I’m repeatedly asked what stretches or exercises someone can do to improve their hip retroversion. This usually means improve internal hip rotation range of motion, and or hip flexion range of motion.

Let’s recap hip retroversion. One way a hip becomes retroverted is from the acetabulum. I already showed some photos of this above.

The other way a hip can be retroverted is due to the femur. It’ll move back, -retro:

Retroverted on left; normal on right:

The consequence of either, whether acetabular or femoral, is a loss of internal rotation of the femur. Red line is less on left (retroverted) than right (normal):

There is also a subsequent gain in lateral rotation. We’ll come back to that.

So, people want to improve their internal rotation. Here is why, for the life of me, I don’t think this can be done. Each time you attempt to push the limits of that internal rotation, what’s going to happen?

In the below GIF, I got rid of the body of the femur so you can more easily see the femoral neck. (The body of the femur is below the neck in this top view):

After a certain point of internal rotation, the femur bangs into the acetabulum. This isn’t only true for retroversion. It’s true for the hip in general, with other structures. Such as a large femoral neck, a CAM deformity.

Particular structure dictates particular movement. Whatever the change in structure may be, a change in movement is likely to occur. Sometimes, this means a loss of motion in one direction, and a gain in motion in another direction. Sometimes, it only means a loss of motion. A larger femoral neck doesn’t gain motion. It only loses it.

What happens when you try to force the hips into a motion they don’t have? What happens when you take a large femoral neck, or a hip with structurally limited internal rotation range of motion, and you attempt to force that range of motion anyways? What happens when you bang on bone?

The bone doesn’t get smaller; it gets bigger. This is why I don’t think you can change these things. And actually, trying to change them likely makes the matter worse. That femur and acetabulum, which are already hitting one another, are going to hit one another sooner if you keep banging on them. They’re each going to adapt to the stimulus of being beat up on by growing more bone, subsequently giving even less room between them. Plus, there’s typically a labrum between the two you’re pinching. All in all, you progressively piss the hip off.

The best way to lessen how much bone is there is to actually leave the area alone. The best way to get rid of bone is to not use it. But there is only so much you can not use your femoral neck, or whatever hip bone. Meaning there is only so much you can change here. You may be able to lessen the size of the femoral neck some by not loading it as much for a while, but if you’re someone with a retroverted hip and later in life you want to engage in an activity needing a hell of a lot of internal rotation, like a hockey goalie (think bringing knees together for a save), you’re unfortunately shit out of luck.

You may try to reorient your hip structure by practicing internal rotation, but other than perhaps some muscular and capsular flexibility, your hips are going to only get worse at internally rotating. The bones are going to get bigger. You can try to work through this, but you’re asking for a hell of a lot of hip pain, that will only get worse, and probably a torn labrum.

Same goes for other hip structures. If you have an usually large femoral neck, activities requiring a lot of hip flexion aren’t going to happen, at least not without a fight. A fight you will probably lose. (A retroverted hip typically has issues with regular hip flexion as well. You often need to accommodate the flexion by externally rotating the hip.)

We all have something of this nature. Only the lucky few end up going through life in activities which cause them to never notice these sorts of things. For the rest of us, you have to accept nature, adapt, and get on with life.

Lebron James is one of the world’s greatest athletes, but only in the context which he’s been judged so far. I promise you he would be a terrible hockey goalie, gymnast, olympic weightlifter, swimmer, and probably require hip surgery soon after trying to be good at some of those.

There is often a bright side though. That hip that’s not so good at internally rotating may be very good at externally rotating. Hockey goalie maybe not; pitcher maybe:

Particularly at the humerus. As a pitcher, a good deal of external rotation can help one throw harder. It provides that whip action:

Ask a pitcher to do much beyond throwing and they suck, but boy can they throw an object.

Unfortunately, many of us learn this the hard way. “You never quit” or something like that pops up in our minds. Some form of stubbornness persists for a while. We can’t all squat ass to grass, throw a ball with no problems, have full range of motion in our hips and shoulders, run 26.2 miles, do a split, go through yoga class without feeling like something will snap.

Don’t let your persistence last too long. The longer you do, the more that femur and acetabulum grow, the worse that hip gets. We can all be active and fit, but in our own way.

–

Postscript- Some questions you may be asking

If you’re wondering if these structures are adaptations or genetic, the answer is both. How much each gets for each structure is tough to say. We’ve had a hard time figuring out height (a good deal genetic, ~80% I believe; a good deal other factors), and these things are more nuanced.

That said, I’ve always leaned towards this stuff being more adaptation than genetic. There is some research discussing this, which I’ll go over in another post. This matters because when you get good at one thing, when you adapt towards one thing, you often can’t avoid getting bad at another thing. If you get good at laterally rotating your hips, you often get bad at internally rotating your hips. I used Lebron James not only due to his athletic ability, but because basketball players are known to lose internal rotation more than non-athletic groups.

If you’re wondering whether this stuff can be changed surgically, like shaving down a femoral neck, people are trying to do this. I wrote about that here. Short version: I doubt it’s a good idea to be attempting this. e.g. Whose to say the bone doesn’t grow right back to where it was? (This isn’t a nose job. A nose isn’t loaded like a femoral neck is.) Do you want to get rid of something that may have been a positive adaptation at one point? What happens if you then find an activity where you want that adaptation back? And we haven’t even gotten to how serious hip surgery is.

–