sacral torsion diagnosis

Sacral Torsion Diagnosis: What you Have to Know

When it comes to getting the right sacral torsion diagnosis, you need three important pieces of information.

These are

  • Which sulcus is deeper
  • Which inferior lateral angle is more posterior and inferior
  • Which side moves first on the seated flexion test.

The quick way that helped me get to a sacral torsion diagnosis very quickly and efficiently is to know how the diagnosis is read.

Sacral torsions are typically read as a left on right, right on left, or any combination of those.

Let’s look at the diagnosis of left on right for example.

This means that the sacrum is rotated left, on a right axis.

You determine rotation by knowing the deep sacral sulcus. If it is deep on the right then the sacrum is rotated left.

You know the axis by the seated flexion test.

If the axis is on the right, then the seated flexion test has to be positive on the left, since axis is opposite the side of the positive seated flexion test.

This gets confusing, but it is something I cover in detail in my course.

Why diagnosing sacral torsions is tough

The dimensionality of diagnosing sacral torsions is tough.

We typically don’t think of the sacrum as a moving bone, since it is so snug in the pelvis.

Sacral torsions are also taught in some very complicated ways, but in reality, if you learn a few rules then they become very easy.

Conceptualizing the movement of the sacrum can be tough, but the way I described it above is a super simple way that helped me absolutely destroy my COMLEX and COMAT exams.

Also, when you first get started with learning sacral torsions, it seems like there are so many diagnosis’s of the sacrum in general, and this can be super confusing.

There are sacral flexions, extensions, unilateral, and bilateral, and it feels like the choices go on and on.

Then sacral torsions can be defined as forward or backward torsions, further adding to the confusion.

The rest of this article will break down how to make sacral torsion diagnosing easy, which is the method I used to get >97th percentile on COMLEX.

Keys to a Sacral Torsion Diagnosis

To diagnose a sacral torsion, you need three pieces of information.

  • Which side is the positive seated flexion test on
  • Which sacral sulcus is deeper
  • Which Inferior lateral angle is more posterior and inferior

If you have those three things then you can make a diagnosis.

Now, how is a diagnosis read?

There are only four options for sacral torsions diagnosis.

These are:

  • Left on left
  • Left on Right
  • Right on Right
  • Right on Left

What does this even mean though?

The first direction is the rotation of the sacrum, and the second direction is the axis it is on.

So, remember “Rotation and Axis” or to make it even easier, remember “RA”.

In the next section we will go through the diagnostic process step by step.

Step by step approach to Diagnosing the Sacrum

Step 1: Perform the seated flexion test. Whichever side moves first or most tells you the axis. If the left side moves first or most, then it is the right axis. Then you already have half of the diagnosis.

Axis is always opposite of the side of the positive seated flexion test. I don’t know why, I never asked why, I just memorized that for testing purposes.

Step 2: Check the depth of each sacral sulcus. Find which side is deeper. Think of this just like diagnosis the spine for somatic dysfunctions.

If the right is deeper, think of it three dimensionally, and realize that if its deeper on the right then it is rotated left.

This also means it is more shallow on the left.

This is just like diagnosing a single vertebrae.

Step 3: Check the inferior lateral angles to see which one is more posterior or inferior. In order for it to be a torsion, the deep sacral sulcus has to be opposite of the more posterior/inferior, inferior lateral angle.

sacral torsion diagnosis
Black circles represent the sacral sulci, red circles are the Inferior Lateral Angles

How Sacral Dysfunctions present in a question

Lets walk through an example.

Patient has sacral pain. Osteopathic structural exam shows the following:

During the seated flexion test the right side moves first.

You note that the right sacral sulcus is deep compared to the left.

The left inferior lateral angle is felt to be more posterior and inferior.

Since the right side moves first on the seated flexion test, this means it is on a left axis.

So the second part of the diagnosis is “Left”

Then notice that the deep sulcus and the ILA that is more posterior/inferior are on opposite sides, meaning it is a torsion.

The right sacral sulcus is deeper, so it is rotated left.

This gives you the first part of the diagnosis, “left”

Putting it together this means this patient has a left on left sacral torsion.

The sacrum is rotated left (since the sulcus is deep on the right), and it is on a left axis (since the right side is positive on the seated flexion test).

As far as knowing if it is a backward or a forward torsion remember the following.

Left on left is a forward torsion

Right on left is a backward torsion

Backward torsions have opposite directions in their diagnosis.

Forward torsions have the same direction in their diagnosis.

Remember those two points and you will be golden when it comes to forward vs backward torsions.

Key points summarized

You need:

  • Which side is positive for seated flexion test
  • The deeper sacral sulcus
  • The more posterior/inferior, inferior lateral angle
  • Remember, the diagnosis is read as “rotation on axis”, so just remember “RA”.
  • Then backward torsions are opposite directions, forward torsions are the same directions.

What causes sacral torsion

Dysnfucntional mechanics, trauma, or injury are some of the common causes.

Typically, as with most somatic dysfunctions there is some issue with the muscles around the dysfunctional area that causes it to be dysfunctional.

If you step off of the curb wrong it can alter the tension in the ligaments and muscles around the sacrum and ultimately cause it to be shifted from its preferred position, leading to a torsion.

What is the most common sacral torsion

This is tough to know. From some research the most common torsion is a left on left sacral torsion.

Why this is, I don’t know, but it seems to be the more common sacral torsion diagnosis made.

What are the Sacral Torsion Symptoms

Any kind of sacral dysfunction will present with lower back pain, pain radiating down the legs, pain that is worse with pressure on the sacrum or when walking.

For the COMLEX, you are guided through the process and don’t have to guess that you need to look for a sacral diagnosis based on vague complaints.

Want to learn more?

Check out my OMM Review Course by clicking the button below


When it comes to getting the right sacral torsion diagnosis, it can be tough.

There are some simple rules to follow and if you can remember these then you will be well on your way to properly diagnosing a sacral torsion.

Don’t get bogged down in all the details, focus on the three steps I mentioned above.

If you want to learn more OMM in that way, then be sure to check out CPM OMM. It is a course I made to help you get questions right on exams. It won’t make you the next AT Still, but it will help you absolutely own your exams.

Thanks for reading

Sean Kiesel, DO, MBA

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