The anatomy of lower back pain


In Germany where I come from, more than half the time people take a sick day from work, it is because of debilitating back pain. And most other Western countries are no different. That is a crazy statistic to me, especially since back pain is something that can be fixed rather easily in most cases. It’s not a broken bone that has to be put back in place, it’s not an illness you have no control over. With diligence and patience, anyone can handle their back pain. When I say this, I mean the kind of back pain that results from muscle imbalances due to too much sitting, one sided movements (think of the shoulder you always sling your handbag over) or isolated muscle training. Of course there are "structural" problems with the spine such as scoliosis that cause back pain due to other forces at play.

When I work with new clients, lower back pain is usually on the top of their list. They think I am a magician for “curing” it, when I simply understand these anatomy principles I will outline here. Bear with me, this article may be a bit technically, but I really want you to understand the anatomy behind your own lower back pain. This is the best way for you to cure your lower back pain yourself. I have tried to keep technical terms to a minimum, grouping together muscles that you may have heard of and that are easier to remember, rather than mentioning something like “biceps femoris” instead of hamstrings :-).

So let’s dive right into the anatomy of your lower back pain.

Anatomy of lower back pain.jpg

When you look at the body, there are 4 specific landmarks in your hips that stand out:

1. Anterior Superior Iliac Spine (ASIS)

This sounds super fancy but basically means the bony part of your hip bones, that stand out (more or less) just underneath your waist in the front of your body on either side. These hip bones can be felt with your fingertips even if you can’t see them protruding when you are looking in the mirror. They are an attachment site for your abdominal muscles. Your abdominal muscles don’t need an introduction. Everyone has an idea where they are and what they give you - think bikini six pack.

2. Anterior Inferior Iliac Spine (AIIS)

The AIIS is much harder to pinpoint but if you take your hip bones and walk half way down towards the groin on that sexy line that men always want to train for, that is where the AIIS sits. This is the starting point of your quadriceps muscles, the front thigh muscles. They are often also referred to as hip flexors which tend to get extremely tight in people who do reversed sit ups wrong, they feel it in their hips rather than in their abs. Most people will have felt their quadriceps when they have sat on a leg extension machine at the gym.

3. Sacrum

The sacrum is a triangular bone which sits at the bottom of your spine. It is made up of 5 vertebras fused together, which makes this area hard and not very bendable. The end of the sacrum is the tailbone, the bottom tip of your spine, which I often refer to in my Pilates classes. If you fall on your sacrum, it is extremely painful as it doesn’t give way. The sacrum is a fancy way of saying just above your butt crack.

The sacrum is the attachment point for a group of muscles, which I will just refer to as your lower back muscles. What is important to know about your back muscles is that there are long ones, which run the entire length of the spine from the head to the sacrum, and there are smaller muscles connecting each of the vertebras. All of them are important to keep your spine upright and make it able to bend into all directions (forwards, sidewards, backwards), as well rotate around itself.

4. Ischiol Tuberosity

A funny name for what is basically your two sitting bones. You may be able to feel them if you grab your buttocks cheeks from behind. The sitting bones are attachment sites for your hamstrings, the muscles at the back of the thighs. Most people will know them from the hamstring curl machine at the gym.

How does lower back pain happen?

In an ideal world, these 4 points are always perfectly aligned with all 4 muscle groups equally strong to keep everything in check. When you are standing tall you have a light curve in your lower back and your tailbone will be pointing just slightly behind you to the floor.

Now let’s see what happens when you throw this system out of balance. Imagine connecting the 4 spots in the graph above into a rectangular box. Here are some scenarios that are extremely common and cause lower back pain to happen:

  • My clients love to train their abdominals. In fact, if I would let them, we would be doing sit ups for an entire hour because they believe this will give them flat abs. The lower back is not so “sexy” to train, because you don’t see it when you look in the mirror, but those abs are always staring at you. If these are overtrained and too tight, they will start to pull the ASIS point up towards your nose. What happens to your box? The top right corner gets pulled up, with the top left corner (sacrum) dropping down, stretching into your lower back and lengthening the back muscles. In that lengthened state, the lower back muscles are no longer able to support your spine in a strong way, thus lower back pain is created.

  • The quadriceps, also sitting in the front of your body, is another muscle group that is often overtrained and too strong compared to other muscles around the hips. If the quadriceps start to pull down the bottom right corner of your box, the box