If I were to ask you what muscle is most responsible for most low back pain, what would you answer?

If you're like most fitness professionals, you would likely answer, 'a tight iliopsoas.'

If I were to ask you what muscle most often needs to be stretched in clients with hip pain, what would you answer?

Again, you would likely answer the iliopsoas.

If I were to ask you what muscle is perhaps the most misunderstood of all muscles in the human body, what would you answer?

If you weren't utterly frustrated by the previous questions, you may not say the iliopsoas, but that would be the correct answer.

The iliopsoas is perhaps the most misunderstood of all the muscles we commonly speak about in the human body. I say 'that we commonly speak about' because there are many other muscles that we don't know that much about either.

This 3-part SPECIAL REPORT, created exclusively for you as a subscriber of FITNESS INSIDER, is designed to give you insider information. Because if you are willing to keep an open mind (which you have already done by subscribing to this newsletter), and you want to help a lot of people (which is the reason you got into this industry in the first place), and you want to be financially rewarded (which you will be) you must be willing to get one thing. What is that one thing?


All specialists in every industry have one thing in common - they have incredible perspective. They are able to consume all the information regarding a particular topic, establish the common 'best practices among them', and disseminate the information to their target audience in a logical, though-provoking, and usable format. If you are able to do that, you will help a lot of people and just as importantly, get paid, as a specialist should.

So this brings us back to the topic of the iliopsoas. I have created this special report in 3 parts:

* Part I: This section will discuss and dispel the 3 biggest myths of the iliopsoas. This information is crucial to understand if we are going to change the paradigm of how the iliopsoas is targeted and treated.

* Part II: This section will go into the 3 functional roles of the iliopsoas, including the anatomy and kinematics of this muscle complex. The dysfunctions that are created by a dysfunctional psoas will also be discussed including the iliopsoas' contribution to posture, stabilization, and movement.

Part III: And finally, the last section will look at the solution to the problem. Now that you understand the myths and have discovered its' function, you will arrive at a strategy to improve function of this awesome muscle complex.

And now on to the 3 biggest myths about the iliopsoas!

Oh yeah, before we get started. This report, along with the information you'll receive all year from industry's most trusted resource for corrective exercise and fundamental training, FITNESS INSIDER, requires you to keep an open mind. Why?

Because much of what you will read will directly contrast, question, and/or contradict what you have learned and come to believe. So if you agree to be challenged and keep an open mind, keep reading. If you want to keep believing what the masses are telling you, stop reading immediately and send this to one of your open-minded colleague. But I suspect if you are reading this, you are a fitness professional who is already thinking bigger about your role in your client's success and thinking bigger about your role in being part of the solution rather than part of the problem. Keep reading and I will elaborate on this last point in part III.



The first myth deals with the iliopsoas's name itself. Contrary to what many of us learned in school, the iliacus and psoas are 2 distinctly separate muscles with dramatically different functional actions despite sharing a common attachment on the hip. These muscles can be likened to the gastrocnemius and soleus of the lower leg, similar attachment at the Achilles tendon but dramatically different functional roles during the gait cycle.

How do we know the iliacus and psoas are two separate muscles?

1. Although they have a similar attachment onto the lesser trochanter of the femur, they have separate tendinous attachments.
2. Although they share similar nerve supplies the psoas is innervated by nerves T12-L4 while the iliacus is innervated by the lumbar nerves L2-4.

So why is this distinction important?

Because once we understand the distinction between the psoas major and iliacus, and that these muscles have very different functional roles, the focus of our corrective and integrative movement approach to dealing with low back, hip, and pelvic dysfunctions can be more specific.

Ø REALITY: The psoas and iliacus are 2 separate and distinct muscles.



When we learned anatomy, we learned that the psoas major is a primary flexor of the hip. And if we look at the attachments, lumbar spine to the lesser trochanter of the femur, it does appear to be a flexor of the hip. Except for 2 problems:

1. When our predecessors studied anatomy and pulled on muscles, the psoas major would appear to flex the hip. However, the cadavers were lying on their backs and they were cadavers - i.e. not living. Muscles have a dramatically different role in the upright posture than they have while lying down.
2. If the psoas major was a hip flexor, then why does it attach to every level of the spine from T12-L5? Why does it attach to every single disc in this level? And why does it fascially blend with the diaphragm and the pelvic floor? This would make the psoas a fairly inefficient hip flexor.

So what does this mean? It means that the psoas major is NOT a primary hip flexor and has a much more significant role in human function. More on these functions in part II.

Ø REALITY: The psoas major is not a primary hip flexor.



Based upon the previous 2 myths, we probably have to start rethinking the myth of the tight/short psoas causing an anterior tilt. As we will see in the functional anatomy portion in part II, the attachments of the psoas major make it very difficult for this muscle to be an anterior rotator (tilter) of the pelvis.

And we often make the mistake of looking at clients posture and just assuming they are in an anterior tilt without really assessing if this is true. It's as Ralph Waldo Emerson once said, "people only see what they're prepared to see." We get it drilled into our heads from the time we first learn postural assessments that everyone is in an anterior tilt.

So why do so many of us (supposedly) have an anterior pelvic rotation (tilt)?

Because we sit too much - or so we're told. I want you to do me a favor - next time you are at a restaurant, airport, or coffee shop, look at how people are sitting. Next time you sit in your car, on your couch at home, or while you are reading this special report, check in with how you are sitting.

What did you discover?

Many of us, along with most of the people you observed, routinely sit in a posterior tilt. And that's how they sit the majority of the time.

So how do these people go from a posteriorly rotated position while seated to an anteriorly rotated position when they stand?

They don't. Most of these clients are in thoracolumbar extension which makes it appear as if they are in an anterior rotation when in actually, they are flexed through their lumbar spine and posteriorly rotated in their pelvis. That's the reason we have so many disc injuries - posterior rotation of the pelvis and flexed spine postures. Anterior pelvic rotation postures actually make it less likely to injure your discs.

One additional reason we see so many clients with posterior pelvic rotation is the over-utilization of flexion based abdominal exercises. These exercises recruit the abdominal muscles as primary flexors of the trunk when their functional role is everything but trunk flexion. However, increased tension in the abdominal wall secondary to crunches, sit ups, and leg lifts drives posterior rotation of the pelvis and lumbar spine flexion.

Do you now see why so many of us suffer from chronic back pain?

Notice the individual sitting in the image to above- posterior pelvic rotation and lumbar spine flexion. Exercises such as crunches (above left) utilize the abdominal muscles as primary trunk flexors instead of their intended role as trunk stabilizers. Result - posterior pelvic rotation and lumbar spine flexion.

Ø REALITY: While some clients do present with anterior pelvic rotation, there are just as many that present with posterior pelvic rotation.


There are many myths surrounding the psoas and iliacus and the goal of part I of The Psoas Syndrome was to lay to rest three of the biggest ones. In part II of this 3-part series, I will introduce you to the functional anatomy of the psoas major, minor, and iliacus so that we can lay the groundwork for part III which will reveal the conditioning of this spectacular muscle.

Helping you think bigger about your role as a fitness professional,

Evan Osar

P.S. Join us in January and begin thinking EVEN BIGGER about your role as a fitness professional at the Integrative Movement Specialist Certification.

Fitness Education Seminars Disclaimer:
No express or implied warranty (whether of merchantability, fitness for a particular purpose, or otherwise) or other guarantee is made as to the accuracy or completeness of any of the information or content contained in any of the pages in this newsletter, web site or otherwise provided by Fitness Education Seminars. No responsibility is accepted and all responsibility is hereby disclaimed for any loss or damage suffered as a result of the use or misuse of any information or content or any reliance thereon. It is the responsibility of all users of this website to satisfy themselves as to the medical and physical condition of themselves and their clients in determining whether or not to use or adapt the information or content provided in each circumstance. Notwithstanding the medical or physical condition of each user, no responsibility or liability is accepted and all responsibility and liability is hereby disclaimed for any loss or damage suffered by any person as a result of the use or misuse of any of the information or content in this website, and any and all liability for incidental and consequential damages is hereby expressly excluded. You should consult your medical doctor before beginning any exercise program.