Left SI Joint and Lower Back Pain Explained

For a long time, I had major problems with my SI joints.

In may cases, SI joint pain is a result of a neuromuscular pattern that Postural Restoration® calls the left AIC pattern.

While pain on the right side of the pelvis is often due the joint being pulled apart, pain in the left SI joint is often related to either compression or weakness in the left hip. Or both.

More specifically, the left leg (femur) doesn’t sit snug inside the hip socket (acetabulum).

This occurs in response to a forwardly rotated left pelvis. When a left hemi-pelvis is rotated forward, the left leg will often compensate into external rotation. It does this in order to stay straight. This is a smart thing to do so that it makes it easier for you to walk and run and do everything you need to do.

  • a picture of a pelvis and femur oriented to the right.
    Pelvis and femur oriented to the right.

But all compensations come with consequences. In this case, certain muscles, particularly the left IC adductor and left hamstrings will weaken because they are now positioned in an elongated state.

As the muscles weaken, the pelvis becomes unstable, and the left SI joint is often a place that hurts as a result.

The following video explains more in depth.




  1. Helen says

    Dear Neal, I emailed you before I saw the picture you are showing, above the rotated left S1 joint, in my MRI’s my body looks like that except it’s my left side that is raised up. I thought by responding to the picture look a like, you could address my problem as to what I was trying to convey. E mail me if you wish. looking forward to hearing from you.

    thank you very much

  2. Devonne Horton says

    I think this video finally describes my left hip and left si pain. I think I have a slightly externally rotated left hip (AFER) with left foot typically slightly everted and left foot forward of right foot. and slightly anterior pelvic tilt and left lateral tilt and possibly rotated pelvis to the right if this makes sense. So if I understand the solution is to strengthen the left ham string to pull the pelvis back and internally rotate the A on the F Any particular exercises to do this ? Than you.

  3. Sam Inalkas says

    Neal, amazingly insightful website and videos. God bless you. My symptoms are similar to what you had initially (left si low back pain, poor right ankle dorsiflexion, right right calves etc). I have been doing PRI exercises diligently but am getting very sore in my low back. Wonder if this could mean that all the flexion is irritating my back? I know LAIC suggests avoiding extension so was a bit confused. Is this soreness normal? Best wishes, Sam

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