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How to Diagnose SI Joint vs Sciatica Pain By Yourself!

Have you been told that your SI joint is the reason for the sciatic pain down the back of your leg? Many people are told that their sciatica or low back pain is from the SI joint. Although this is a very commonly diagnosed condition, is it being misdiagnosed? Or over-diagnosed? In my opinion yes! So let's learn about the differences between these 2 conditions and how you can determine if you have an SI joint issue or classic sciatica!

First Off, What is SI Joint Dysfunction?

Dysfunction in the sacroiliac joint, also called the SI joint where your pelvis meets your sacrum at the base of your spine, can sometimes cause lower back and/or leg pain. Leg pain from sacroiliac joint dysfunction can be particularly difficult to differentiate from radiating leg pain caused by a lumbar disc herniation (sciatica) as they can feel quite similar. SI Joint Dysfunction is typically a result of too much or too little movement with involvement from the surrounding joints and muscles.

What is Sciatica?

Sciatica refers to pain that radiates along the path of the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. Sciatica is most commonly associated with a disc herniation that is going to push out on that nerve root, which is going to send signals of nerve pain down the leg. This is often felt as sciatic pain when bending forward, backward, or in various other directions involving the hips/spine.

How to Determine if you have SI Joint Pain?

1. Fortin's Sign

This is a sign when the individual dealing with low back issues is asked to identify their location of pain and they point directly to their SI joint. SI joint pain tends to be very localized and this identification may be 1 indication of SI joint involvement. However, the downfall of this is that we never want to rely on the location of the pain as the location of the problem, as many sciatica-related pains can refer through the SI joint region. This is why a proper mechanical assessment is so important for finding sciatica relief.

2. Pregnancy

If you are pregnant and have localized lower back pain in the SI joint region, this significantly increases the likelihood that your pain is in fact from the SI joint. Now, why are pregnant women much more susceptible to SI joint dysfunction? Because during pregnancy a hormone is released called "relaxin" which is responsible for relaxing all the ligaments and muscles around the pelvis. This reduces the support around these joints and the added weight from pregnancy simply compounds this additional stress and causes further irritation.

3. Orthopedic Testing via Laslett's Cluster

This form of testing requires a clinicians skill-set and is not something you can do totally on your own. However if you have been diagnosed with SI joint dysfunction and were NOT taken through these tests, I would highly recommend getting a 2nd opinion due to how many cases I personally see misdiagnosed with SI joint dysfunction. The picture and video below displays these testing procedures.

How to Determine if you have Sciatica?

1. Toe Touch Test

When you bend forward as if you are trying to touch your toes, if you feel some extra tightness or pain shoot down one of the legs it's most likely sciatica from a disc/nerve issue. Sciatic pain when bending forward is most likely from a disc or a nerve in the low back because when you're bending forward you're not overly compressing or stressing the SI Joint. Most of the time compressive or shearing tests will aggravate the si joint the most, not these simple ranges of motion. With that being said, sometimes in unique circumstances the sciatica will be triggered by leaning backwards instead of forwards as not every situation is the same. So what is most likely happening is that the disc is either irritating that nerve root more or that the nerve is stretching and that nerve is irritated and it doesn't want to stretch so it's creating the symptoms down the leg.

2. Nerve Tension Test

Finally, the last quick test you can try is to sit in a chair, round your low back, bring the chin to the chest, and now whichever leg that you have the symptoms going down straighten that leg out with the toes pointed to the ceiling as shown in the picture below. If you feel like it's putting a zinger down your leg or additional tightness then it is mostly likely sciatica. You can also try this next step.... while you hold this position, look up towards the ceiling....Did it go away or reduce? Might not be the SI joint! Or while holding that same position now point the foot away from you. Did it go away or lessen? That's probably not from SI joint dysfunction!

How do you Fix SI Joint Pain?

My primary approach to true SI joint pain is 1st to assess aggravating and palliative movements to determine movement restrictions. After this, generally speaking we will address the low back, core, hips, and breathing patterns. Remember SI joint pain is typically a result of surrounding areas not doing their job, this is why we need to look at all these other regions. Here are 3 of my favorite exercises to help these regions, but once again you may need to reach out for my help in determining which exercises are right for you instead of guessing your way through it!

  1. Deadbug, this exercise is phenomenal at properly activating the core and diaphragm as it was meant to be to improve the function of the low back and all surrounding areas.

Deadbug shown here from 1:40-2:20

2. Bird Dog, a classic movement to work the posterior chain/posterior oblique sling which perfectly runs across the SI joint by activating the glute and back.

Bird Dog

3. Knee Plank Clamshell, a great exercise that activates the hip/glute med to improve hip function and strength.

Knee Plank Clamshell

How do you Fix Sciatica Pain?

There is no easy way to describe this over text as each individual is different with nerve-related issues and should be handled. as such. You could take 10 people with sciatica, and all 10 would have a slightly different program based on their symptoms and what we determine their body likes. Once again I have hundreds of videos on my instagram but at the end of the day, these are just guesses for you. I am here to help you determine the right dose, frequency, and strategy of movements that will work for you. So if you are serious about resolving this you need to submit an application for my coaching!


So in summary, SI joint dysfunction is not as common as most think. It is very mis/over-diagnosed and many individuals with low back pain or sciatica need a different approach for this. We discussed a few signs that support SI joint dysfunction as the root of the issue, as well as some characteristics of classic sciatica that could help determine if that is the root of the issue. We discussed some of my favorite exercises to reinforce the core, hips, and low back that you could start with if you think you have SI joint dysfunction OR sciatica. To be totally honest, I have only diagnosed 2 TRUE SI joint dysfunction cases in my career. It is that rare/overdiagnosed, so if you have any symptoms traveling down the leg it's safe to assume it's from the sciatic nerve and probably not the SI joint. But at the end of the day, you need a proper assessment and proper plan to truly understand what you are doing!

What is the Next Step?

This can vary from person to person but in my experience with online clients around the world there is a similar pattern among many individuals with disc herniations or sciatica that is commonly missed. The majority of my clients in the RehabFix Online Low Back Program have had low back issues for years and have tried Chiro, PT, medication, injections, orthopedists - you name it! It seems like they all were missing some key components..... First I would recommend my FREE Low Back Webinar that discusses multiple factors that contribute to lower back pain!

Then if you still feel like you are

  • unsure

  • confused

  • wasting time

  • missing out on your life at 100%

  • wasting thousands $$$ on interventions that aren't producing results

  • working with someone you feel does NOT care about YOUR GOALS

  • worried about this leading to drugs or surgery

Then it's time to take action! No time to waste!

Ready to ATTACK Low Back Pain or Sciatica?

Are you sick of guessing your way through this low back pain?

Want to prevent drugs or surgery?


Thanks for reading! -Dr. Grant Elliott


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