I’ve had a lot of questions on how to tell which part of the scoli curve is concave versus convex. It’s time to have a lesson on deciphering scoli curves.

Every scoliosis curve has a concave and a convex part. They are opposing sides of the curve. Most scoli spines have multiple curves and therefore have multiple concave and convex parts of the spine.

I have a silly way to remember which side is the concave part of the curve by thinking of an actual cave made out of rock. If I’m inside a cave it’s round over my head. If I’m “in” the cave portion of a scoli curve it’s rounded over my head. Therefore, I’m “in” the concave portion of the curve.


If I remember which side is the “cave” (concave) part of a curve, the opposite side of the curve is the convex portion. To give you a visual way to remember the convex part of a curve think of the rounded mirrors used in stores to prevent shoplifting. It’s rounded out, or curved out so the store manager can see lots of people in the store from standing in one spot. The convex part of the scoli curves rounds out.


I’m going to use the picture sent to me by a young woman in Asia I used in the blog post here to describe this further.


The numbers 2 and 3 are the concave portions of the curves and numbers 1 and 4 are the convex portions of the curves. Can you see how 2 and 3 are “inside the cave” of the curve? Can you visualize how 1 and 4 are going out?

Most people’s muscles are beefier and more built up on the convex portions of their curve (1 and 4 in the picture above). While they are the longer muscles, they’re usually the workhorse muscles and have been attempting to hold the back upright for many years. The muscles inside the concave portion are shorter and usually more atrophied, which would be 2 and 3 in the picture above.

Let’s take the norm of muscle development for scoliosis and turn it on its head. I wrote about Usain Bolt here, who happens to be of my favorite people living with scoliosis. For the third Olympics in a row he’s won the 100-meter dash and continues to reign supreme as the fastest man in the world. Yes, he has scoliosis if you didn’t know. And no, he has never worn a brace or had surgery.


His back fascinates me, scoli anatomy nerd extraordinaire that I am, because he has trained the muscles in both of his concave portions to be BIGGER than the convex portions. That’s crazy from an anatomical standpoint!

I don’t want to get any emails from people saying that’s just how he was built. No way. No scoli backs are built like that. I’m sure that’s how his trainers have halted the progression of his curves and helped his back, pelvis, and legs to function at the elite level that they’ve function at over the last 3 Olympics. He has more muscle in the concave portions of his curves because he worked those areas of his back to help stabilize his scoli curves.

There you have a break down of the convex and concave portions of curves, the natural muscle development, and then what the fastest person in the world has done with his scoliosis to throw the normal concave/convex muscle development on its head.

There is one question that remains still:

How do I build up the muscles in my back to halt to progression of my curve?

I’m pleased to announce that Spiral Spine will be launching a new video series called Scoliosis Education.

• You’ll learn how to untwist scoliosis using movement.
• I’ll teach you how to analyze scoli so you can see what I see and do it on your own.
• You’ll also learn how to put an exercise session together for a child or teenager with scoliosis, that engages their mind and motivates them to workout and do corrective exercises.

I’ll be releasing multiple 30-45 minutes videos over the course of this year. Each video will be FREE for streaming for the first 24 hours after it’s released. To register for the first webinar click here.

Erin Myers


24 thoughts on “Concave vs. Convex Scoliosis Curves

  1. John Kwak 2 months ago

    So you have to build up the concave side? And stretch out the convex side? I always thought it was the other way.

    1. Erin Myers 2 months ago

      My guess is that your concave side is much weaker than your convex side. You must have a goal to get them to equal strength if not the concave stronger than the convex. The convex is long, yet overworked. Release the spasms on the convex side with a ball. Once those are calmed down and the concave is built up more, then you can work on shortening the convex. -Erin

  2. Joanna 2 months ago

    So if I get this right:
    Convex = stronger and longer muscles
    Concave = shorter weaker muscles

    1. Erin Myers 2 months ago


  3. Viviana 3 months ago

    I’ve known to have scoliosis since i was 12 yo. It was 20 degree curvature on my lumbar back then. Now im 26 yo, and the curvature increases to 35 degree on the lumbar and 10 degree on my upper back. Doctor said that i have to go swimming but i dont feel any body improvement from swimming. Reading Usain Bolt really give my motivation back to have normal body posture. Could you please tell me
    1. which side of the body should i trained more? The concave or convex side?
    2. What exercises will be suit for me?
    Thank you before
    Best regards

    1. Erin Myers 3 months ago

      Hi Viviana, Initially you need to work the concave part of your curve. It’s atrophied in comparison to your convex side, which is hyperactive. You can watch Untwisting Scoli: Maya (go to the shop page of this site for those links) or Analyzing Scoliosis (https://goo.gl/bXDKfY, that’s not on the shop page quite yet) for exercises. Also, my latest book, Analyzing Scoliosis, will be out hopefully in January and you’ll want to get that as there are many exercises in there you can do. Keep an eye out for that. Great job on being proactive with your spine. Blessings, Erin

  4. emmanuel ben-edigbe 6 months ago

    Erin Myers,
    thank you and best wishes.

  5. Nat 6 months ago

    I need some help! I had an x-ray a while ago and I don’t have the image itself anymore but I do have the written details… “Mild lumbar scoliosis concave to the right” (with “curvature of lower thoracic spine to the left”). Does “concave to the right” mean I have dextroscoliosis (curve to the right) or levoscoliosis (curve to the left)? So confused!

    1. Erin Myers 6 months ago

      Hi Nat,

      It means your scoli spine is going to the left in your lumbar spine, so the right side is the concave side and your left side is your convex side. I’d suggest you do dot sticker pictures, a diagram sketch, and learn how to use a scoliometer since you don’t have your X-ray anymore. You can learn to do those on any of my videos or on the free starting point series at the top of the home page.

      Erin Myers

  6. Arturo 11 months ago

    But concave or convex are only names to refer to the outside and inner sides of the curve, waht is important here is to say that every scoliotic people MUST to know that the inner side MUST to be relaxed and the outside strenghtened. The oppossite would be something like a suicide.

    1. Erin Myers 11 months ago

      Most people’s convex erectors (et. al.) are in constant spasm because they are the workhorses and are on too much. Palpate the muscles on the concave part of someone’s spine and it’ll be nothing. No muscles are firing. To find balance, stretch then strengthen the concave muscles in a LENGTHENED state. Only then will the convex muscles be able to not be in constant spasms. If you strengthen the convex muscles immediately they will be in constant spasms. Don’t believe me? Try it. Eventually both sides will be strong enough to support you and THEN you can shorten the convex muscles to help to continue the process of stacking up the spine.

  7. Arturo 11 months ago

    I don’t know what happens with the editor. A concave angle is > 180º (is greater than 180º)

    1. Arturo 11 months ago

      so the outside of the curve is the curve is the concave side,

    2. Erin Myers 11 months ago

      It doesn’t matter what degree a curve is at. The inside is always the concave part and the outside is always the convex part.

  8. Arturo 11 months ago

    Hi Erin, What you says about concave and convex side is what surgeons uses to say, but is a wrong definition. A convex angle is 180º, so the outside part of the curve is the concave side, and certaily muscles of the outside part are not only longer but also weaker and because the shape they are not able to keep the curve reduced. Muscles of the inisde part of the curve are shorter and tight, certainly are not alowing the stiff spines to be flexible, so the key is to straight the inside part and strenght the outside part. Best regards

    1. Roxy Stuart 11 months ago

      Hi Arturo, Thank you for your comment do you have any website that can explain how to do this? I am in a lot of pain and I was going to try spiral spine but not if it is going to make me worse. Thanks

      1. Erin Myers 11 months ago

        Hi Roxy,
        It will not make you worse. I’ve helped so many people straighten their spines both in my studio and around the world. I just got done teaching a Pilates class where a woman was in a lot of pain because she had been strengthening the convex part of her curve in an attempt to straighten it, and she was in so much pain. She needed to release that, and build up the convex part in an elongated state. Once those are strong enough, she can start to work the other side again. If you strengthen the convex side immediately, like this Pilates client, you’ll end up in spasms.

  9. Arturo 11 months ago

    Hi Erin, What you says about concave and convex side is what surgeons uses to say, but is a wrong definition. A convex angul is 180º, so the outside part of the curve is the concave side, and certaily muscles of the outside part are not only longer but also weaker and because the shape they are not able to keep the curve reduced. Muscles of the inisde part of the curve are shorter and tight, certainly are not alowing the stiff spines to be flexible, so the key is to straight the inside part and strenght the outside part. Best regards

    1. Erin Myers 11 months ago

      The basic definition I said above is correct. It’s not my “opinion” or surgeons “opinions”, it’s a factual definition. If you don’t believe me, look up the basic scientific/mathematical definition online.

  10. octavia Hendersons 1 year ago

    Fantastic breakdown! I was engaged the whole way through your article. Plus, I didn’t know that Bolt has scoliosis! Thank you for sharing your expertise.

  11. Deb Batten 2 years ago

    I would like to register for the scoli education webinar mentioned above but when I click on “register here” I’m take to the page about renting the Maya video. How can I register for your upcoming webinar?

    1. Erin Myers 2 years ago

      Hi Deb, The scoli education webinar has already happened, but is available to rent for 72 hours on the Shop page of SpiralSpine.com for just a few dollars. -Erin

      1. Barbara Kerwin 1 week ago

        Hi Erin,
        I have left thoracic scoliosis, and right lumbar scoliosis. Some parts of my back are stretched, some are scrunched. Which areas do I need to strengthen, and which should I stretch?

        1. Erin Myers 2 days ago

          Hi Barbara,
          As much as I’d like to “prescribe” some exercises for you, it’s just never that easy because every scoli body is different. I’ve created many tools to help you figure out which areas of your body need to be stretched and strengthened. Check out free, short videos called the Starting Point Videos available on the top icon bar on the home page of this site. I have many online workshops available on the shop page as well. In book form, you can get Analyzing Scoliosis, which is available on amazon. You’ll learn more about your scoliosis than you could have dreamed. You could also schedule an online, virtual lesson with me where I could analyze your scoli for you and give you exercises that way. If you’re interested, you can email my studio through the contact page of this site. There are lots of ways you can learn about your scoli. Blessings, Erin