The Problem With “Normal”

Mobility is one of the most searched topics in fitness right now.

Most people who start working on it are dealing with something. They feel tight. They move in ways that don’t feel right. Some are in pain and looking for a way out of it.

So they start looking for answers. And at some point, they find a number or a metric of success.

A degree of hip flexion they should have. A squat depth they should be able to hit. A shoulder range that’s considered healthy. A position in yoga or 90/90 that “everyone should be able to do.”

Is that an actual standard worth chasing, or is it just what we’ve decided normal looks like?

That question is worth sitting with before you spend another six months stretching toward a target that may or may not apply to you.

Clients ask me a lot about joint range of motion norms, and it’s a fair question. We try to standardize everything in training, and norms give people a target, especially someone who has no idea what they should even be working toward. That’s also what makes this conversation complicated. The number exists for a reason. It just doesn’t tell the whole story.

Range of motion norms come from measuring joint range across large groups of people and finding the middle of the distribution. Think of them like average height. Most adults fall somewhere in a predictable range, but plenty of people sit well above or below it, and none of that makes them abnormal.

You can see some of the more common range of motion norms here. Keep in mind that norms change based on demographics (e.g., sex, age), but this gives you an idea of what we’re talking about here.

Clinical norms give us a rough sense of where most people land. They are useful for that, but they were never designed to tell any individual what they should be able to do. They don’t account for training history, injury history, age, or body type.

And they definitely don’t account for the fact that two people with identical training histories can have dramatically different joint ranges—not because one works harder than the other, but because their bones are shaped differently.

That last part is where most mobility content goes quiet.

When a joint isn’t moving as far as you’d like, there are two very different reasons why. Understanding which one you’re dealing with changes everything.

The first is a built-in limit. This is the range your skeleton allows. Bone shape, socket depth, and the architecture of the joint itself. These factors set the ceiling on what’s physically available. In adults, they don’t change with training. No amount of stretching or soft-tissue work alters bone structure.

The second is an untrained limit. This is range you’ve lost, or never developed, through disuse, compensation, or injury. These limits are trainable. This is where mobility work earns its place. A hip that hasn’t been loaded through its full range of motion in years will feel restricted, but that restriction lies in the tissue and in tolerance. It responds to progressive training.

The problem is that most mobility content treats all limits as if they’re the second kind. Train harder, stretch longer, be more consistent. That advice is sound when the limit is trained. It is useless and potentially harmful when the limit is built in.

Some cases don’t fit neatly into either category.

Some people are working around changes they don’t know exist. A labral tear, significant cartilage loss, or bony changes from a past injury that was never imaged. These can look and feel like a trained limit at first. They respond partially, then plateau, or they produce symptoms that don’t quite fit the pattern of a normal tissue restriction.

This is where the right clinical relationship matters. Not just someone who looks at imaging and reaches for their surgical tools, but someone who understands anatomy, imaging, and training well enough to know what’s actually addressable. A labral tear, for example, is something you can work around and improve through sound training practices. A bone spur is not. That distinction changes the entire plan, and you can’t make it without someone who knows the difference.

The femur sits at an angle within the hip socket. That angle, called femoral version, varies enormously across healthy adults, and the spread between individuals is significant enough that two people can have completely different mechanical starting points while both being considered normal.

Some hips are built to rotate inward easily. Others rotate outward easily. A person whose hip is built toward internal rotation will often show a lot of it and very little external rotation. That’s not a mobility deficit. That’s architecture. And a meaningful number of people have bony hip shapes that physically restrict certain ranges entirely, many of them with no symptoms at all. Pushing those people toward positions their structure won’t allow doesn’t build range. It builds irritation.

None of this means norms are useless. Some ranges are worth pursuing for nearly everyone because structural variation rarely blocks them.

The knee is the clearest example. Full extension and roughly 150 degrees of flexion are achievable for most people without a structural reason for limitation. If someone is missing those ranges, it’s almost always an acquired limitation: disuse, swelling, tissue restriction. That’s worth addressing.

The principle here is not that norms are wrong. It’s that they apply more reliably to some joints and some movements than others. The further you get into ball-and-socket territory—especially the hip and shoulder—the more individual variation matters and the more carefully norms need to be applied.

Here is the failure mode worth naming.

The trainee doing hip internal rotation drills three times a week who isn’t making progress and is starting to feel a pinching sensation at end range may not be undertrained. They may have already reached their built-in limit. Pushing harder against a hard stop doesn’t build capacity. It builds irritation.

There is a meaningful difference between a restriction that feels like tension and gradually yields, and a restriction that produces a sharp, compressed feeling right at end range. The first is a conversation with tissue; it has give and responds over time. The second doesn’t yield because it isn’t soft tissue.

One you train through. The other, you work around.

Working around it doesn’t mean giving up on range. It means finding the positions where the joint can be loaded without creating that response and building capacity there. The goal is still more usable range. The path just looks different.

So, back to the original question. Is the range of motion standard you read about true, or is it just what we’ve decided is normal?

Honestly, both.

Some of it reflects genuine functional thresholds; ranges that matter for how you walk, squat, reach, and load. Those are worth pursuing.

Some of it is population-average dressed up as a prescription. A number that describes most people, applied to everyone, regardless of what their structure actually allows.

The more useful question isn’t whether you match a published number. Ask instead,

What range of motion do I need to complete a specific task?

A hip with 30 degrees of internal rotation, because that’s what the anatomy allows, but that only uses 10 of those degrees in training, has real room to grow. A hip with 30 degrees that consistently uses 25 of them is close to its ceiling. Those are two different training problems. Neither of them is answered by comparing to a norm.

Use norms as orientation, not judgment. They can tell you roughly where you stand, flag ranges that are clearly below functional thresholds, and point you toward things worth investigating. That’s legitimate.

But they can’t tell you what your structure allows. And they can’t tell you whether a limitation is untrained or built-in.

That requires paying attention to how a restriction actually behaves; whether it yields with consistent work or stays fixed no matter what you do. Whether it feels like tension or like a wall.

Most people don’t ask that question. They just try harder.

The goal of mobility training isn’t to match a textbook. It’s to build as much usable capacity as your structure allows, and to understand what you’re actually working with before you decide how hard to push. That’s not a reason to stop. It’s a reason to ask better questions before you do.