Range of motion - ROM - seems to invade every discussion about exercise.

I’ve noticed this since entering the “fitness industry” years ago, and our discussions about ROM continue to be as low-resolution as ever.

As of late, I’ve also noticed that the most common questions I get whenever I post a video of an exercise - regardless of what the exercise is for - are all about ROM. They usually look something like these:

1. “Why aren’t you using full ROM?”

2. “Why aren’t you locking out fully?”

3. “Why aren’t you going all the way down"?”

And so on.

Today, I will attempt to lay out a framework for the broad topic of ROM. Let’s start with definitions.

What is ROM?

Range of motion refers to the distance through which something travels in the context of any movement.

Most people speak of only one kind of ROM, but there are multiple types of ROM that need consideration in the context of exercise:

1. Implement ROM is the category that the vast majority of people refer to when they discuss ROM. Implement ROM refers to how much an external object - like a barbell, DBs, cables, etc. - travels during an exercise.

2. Joint ROM - refers to the range through which a specific joint or joints travel during or outside the context of an exercise.

   • Many physical therapists use this kind of ROM testing outside the context of exercise, which we will discuss later.

3. Muscle ROM - refers to the range through which a muscle lengthens and shortens during an exercise.

4. “Passive” ROM - is a subcategory of joint and muscle ROM that refers to the range through which a joint or joints can be moved by an external force (typically a person, but it could also be an implement) when an individual is not attempting to move.

5. “Active” ROM - is a subcategory of joint and muscle ROM, which refers to the range through which a joint or joints can be moved via active contraction (by the individual alone).

All of these different categories are intimately related. However, when attempting to understand the complexities of ROM in the context of exercise, it is important to make these distinctions for reasons that will soon become clear.

Implement ROM

Implement ROM is the most discussed and yet the least relevant category to consider.

It’s not that implement ROM is irrelevant, but the range through which you choose to move an external object is arbitrary, or at least a secondary consideration.

One of the clearest examples of arbitrary implement standards comes from powerlifting and, specifically, the bench press.

Athletes and lifters are taught early on (usually in high school or even before) that touching the barbell to your chest is paramount.

But telling an individual to touch the bar to their chest pays no mind to what an individual’s joints, ligaments, tendons, and muscles have to say about the amount of force and motion that person experiences.

Depending on an individual’s joint structure, amounts of muscle or fat, connective tissue status, muscular strength, and skill, touching the bar to one’s chest may or may not be appropriate for training the pecs, front delts, and triceps.

Some individuals may be comfortable touching the bar to their chest, while others might never be able to do it without some complication or weird feeling in their shoulders, elbows, and wrists.

This is not something you can generally predict but should be investigated on an individual level.

Are you not convinced about the arbitrary nature of something like touching a barbell to your chest?

Think about the barbell deadlift.

Who decided what the diameter of a 45-pound plate should be (17.72 inches)?

Whoever did (thank you, whoever you are) decided the amount of ROM that everyone who deadlifts should use without considering the individual factors discussed above.

Imagine that the diameter of a 45-pound plate was twice its current length. Everyone would be deadlifting with the bar (most likely) starting above their knees—which we’d call “partial ROM” if we ever saw someone deadlifting that way now.

Implement ROM should depend on all the factors listed above, plus considering an individual’s goal with any exercise.

Remember…implement ROM is arbitrary. That doesn’t make it irrelevant (and in many cases, this can be a helpful strategy to put boundaries on ROM), but it does mean that it should be considered after the other kinds of ROM we’ll discuss.

Joint and Muscle ROM

While it’s impossible to separate joint ROM from muscle ROM - especially in an exercise context - I believe it’s important to distinguish between the two clearly.

Joint ROM is specific to the contact surfaces between bones, while muscle ROM is specific to the length of a given muscle.

For example, the elbow can straighten to an average of 0º (where the upper arm and forearm are roughly parallel). When we assess ROM at the elbow, we are describing how the contact surfaces of the upper arm and forearm relate to one another.

If the elbow is at the 0º (straight) position, we can say that all three triceps are relatively short.

But if the arm is raised above the head while the elbow is still at 0º (straight elbow), the long head of the triceps—the one that attaches to the shoulder blade—will lengthen to increase its ROM into the stretched position while the other two triceps will remain the same length.

So - joint and muscle ROM are directly related but should be examined individually when analyzing exercise.

Another example is lowering the bar to my chest during a barbell bench press, which will lengthen most of my pecs to a large degree.

However, where the individual directs their arm path - a wider press versus a narrow press - will influence which pecs lengthen the most and, thus, which pecs are trained through the largest ROM.

For example, if someone performs a wider grip bench press, they will lengthen the upper pecs more than the lower pecs per degree of upper arm motion backward.

If someone performs a narrower grip bench press, they are likely to lengthen the middle and lower pecs more than the upper pecs per degree of upper arm motion backward.

The shoulder joint may reach an end-range “extended” position in both cases, but the muscular influences between these positions are quite different.

Joint ROM Considerations

The structural components of the joint in question define an individual’s ROM at any given joint.

For example, the glenohumeral (GH) joint of the shoulder can, on average, move through 160-180º of flexion (raising the arm forward and upward). But the elbow can only typically move through 120-150º of flexion (bending), depending on the structure of one’s elbow and the size of their arms and forearms.

Is this a bug or a feature? Should the shoulder move the same as the elbow?

Or is this simply a structural feature of these joints? (hint: it’s a feature).

In addition, not all joints move the same way, and some have structural limits that prevent them from moving in specific directions.

For example, the GH joint can effectively move in any direction (with eventual limitation), but the elbow can only move in one direction.

Again - is this a bug?

No. This is simply the nature of these joints and how they are meant to move -and we should look at the individual variance in joint ROM the same way.

Active VS Passive ROM

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If you continue reading, you’ll learn:

• How to squat for quads versus glutes and how they’re different.

• What is exercise ROM, and why does it matter so much?

• Why ROM assessments are arbitrary and often unhelpful.

• How active and passive ROM are generalized and why this is silly.

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