positive sphinx test
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Positive Sphinx Test: What is it, and What Does it Mean

What is a positive sphinx test? This article will cover that and a little more. First though, its important to let you know a little bit about Comprepmed.

When it comes to studying, I think we can all agree that sometimes it just sucks.

In undergrad, I didn’t do so hot. I had average grades, got a downright average MCAT score, and somehow made it into Osteopathic Medical School.

In DO school, I was able to get a 4.0 and score >97th percentile on my board exams.

So, in short I owned med school!

Comprepmed is all about helping you learn how to own med school too. By reading these articles and going through my course, you will get higher scores on exams, and eventually get into the residency you want.

Lets get to this article about the Positive Sphinx test.


A positive sphinx test means that the sacrum has a dysfunction that is either extended or backward torsion.

Physiologically, this is all that it can mean if the test is positive.

This is one of those things that through 1000’s of practice questions you really start to understand.

The sphinx test in and of itself can be confusing, and even more frustrating is that nobody simplifies it to the point that you can get questions right on tests.

Truth be told, if you understand the sphinx test that will probably be atleast 5-10 questions you will be able to quickly get right on any given test that has OMM on it.

What is the sphinx test

The sphinx test is a special test for diagnosing the sacrum and sacral dysfunctions. It is a quick and easy way to rule out multiple different diagnosis’s.

Essentially to perform the sphinx test you do the following:

Have the patient lay prone

Plae your thumbs in the sacral sulci

Have the patient extend back and place their elbows on the table

Feel for changes in symmetry in the sacral sulci

Summary of findings:

There are only two options for the sphinx test.

Either the sacral sulci will stay asymmetrical/become more asymmetrical

Or, the sacral sulci will become less asymmetrical.

positive sphinx test

What does a positive sphinx test mean?

If the sulci become more asymmetrical/stay asymmetrical, then this is a positive test and means the sacrum is either extended or in a backward torsion.

If the sulci become more symmetrical then it is either a flexed sacrum or a forward torsion.

That is the meat and potatoes of this article.

This is also the key to getting points on your tests. Distill the OMM down to the simplist and most straightforward points, and keep it test relevant.

CPM OMM focuses on simplifying OMM and keeping it very test relevant.

Check it out below.

Key learning points

Positive Sphinx test:

Findings: Sacral sulci become more assymetrical, or stay asymmetrical

Meaning: Backward torsion or extended sacrum

Negative Sphinx Test:

Findings: Sulci become more symmetrical

Meaning: Flexion, or forward torsion

If you just remember the positive sphinx test, then you don’t have to try and remember both of them. This is how I approach OMM, if two things are opposite, just remember one and you will be able to figure out the other.

The sphinx test in a question

A 29 year old male presents to your clinic for lower back pain. The provider decides to do an osteopathic structural exam.

You find that his pain is greatest around the base of his sacrum. You decide to narrow it down by doing a sphinx test. On exam you find that when he goes into extension your thumbs become more asymmetrical.

Which of the following is a possible diagnosis?

  1. Right on left sacral torsion
  2. Right on right sacral torsion
  3. Left on left sacral torsion
  4. Right unilateral sacral flexion

Correct answer: A

How do you get to this with just one physical exam finding?

Simple, with a positive sphinx test (thumbs become more asymmetrical) you know it can only be a backwards torsion (right on left or left on right) or a sacral extension.

The only option there that fits that is option a.

Check out a basic sphinx test here


Summary of the Sphinx Test

The sphinx test is a pretty simple way to rule out sacral diagnosis’s quickly. Also, it is a great way for test writers to test your knowledge of a simple OMM diagnostic tool that not a lot of people will spend time studying.

If you know it, you will be able to quickly get answers right that not many other will, which translates to you scoring way higher then others on your exams.

I hope this was helpful.

Sean Kiesel, DO

FAQ’s related to a positive sphinx test

What does a positive spring test mean?

Positive spring test means just the opposite. A spring test is where you take the heel of your hand and apply pressure to the base of the sacrum.

If there is spring, or the sacrum moves forward, then it is a positive spring test and this means that the sacrum is either in flexion or a forward torsion.

What is PSIS test?

There are a lot of students that ask this. Truth is, there isn’t a PSIS test.

The PSIS is a component of the seated and the standing flexion tests.

The seated flexion test is testing for sacral dysfunction, while the standing flexion test is looking for innominate dysfunction.

What is a seated flexion test?

The seated flexion test is a way to test for sacral dysfunction. It is easy to get this confused with the standing flexion test.

The standing flexion test is testing for innominate dysfunction.

They are both useful and both serve their own purpose.

What is the Sphinx assessment?

The sphinx assessment is just another name for the sphinx test, don’t be fooled when someone says this, it means what you already know.

If you liked this article then be sure to check out these other similar OMM related articles:

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