A few weeks ago, I taught a Yoga Tune Up® class that focused on the psoas.
I started by educating my students on the very basic anatomy of this deep gut muscle. All across the room I begin to witness complete silence. I guess most of the students  have not connected to their p-s-o-a-s in a very long time.
The psoas, also known as a primary hip flexor and ‘’13th Organ,’’ originates at the transverse processes of last thoracic and 5 lumbar vertebrae (T12-L5), bisects through deep inside of the gut and attaches at the inner femur (thigh bone). This is a very unique muscle that both flexes and laterally rotates the hip, and is one of the major muscles responsible for walking.
The lower portion of the psoas intertwines with the fibers of the iliacus, and together they form a muscle group known as iliopsoas.
The psoas also affects the structure of our upper body. It originates at T12 which is a major attachment site for the trapezius muscle. Through this junction the psoas can send forces into the upper body and directly affects the level of shoulder flexion (reaching your arm above your head).
In addition, the most important role of the psoas is the muscular support it provides for the lumbar plexus, a network of nerves which originate in the spinal cord and impact the wellbeing of the body’s digestion and elimination systems. Unlike muscles such as the hamstrings, which you can feel immediately due to their nerve endings informing us when they’re being worked, the psoas is much more challenging to propriocept (sense and feel). This is because it’s situated deep within the body behind the abdominal organs. It is the deepest and largest core muscle of the body.
In a nutshell-the health & vitality of our psoas affects the health of our entire body.
WHAT MAKES THE PSOAS TIGHT AND RESTRICTED?
Most of us tend to weaken our psoas just by living in today’s busy world. Prolonged hours of sitting,running, cycling or any repetitive movement which involves lot of hip flexion would create imbalances within the psoas tissues.
Other areas of concern:
POOR ERGONOMICS
TRAUMATIC EVENTS
BAD SHOE CHOICES
EMOTIONAL & PHYSICAL INJURIES
OVERTRAINING
CAR ACCIDENTS
BAD FALLS
MUSCULAR/SKELETAL IMBALANCES
Come back for part 2 of this article on Friday (and then read how you can re-balance your psoas from inside-out).
I used to have lots of problems with my psoas from years of dance training, but yoga has really helped me learn how to be gentle and move thoughtfully so as not to further weaken it and actually helps to strengthen it.
Coreso Leg Lifts and Yogi Leg Lifts are terrific psoas strengtheners! Hope you will get chance to come across them. I know Jill is teaching amazing Coreso Leg Lifts variations on her COREGEOUS dvd!
I sit at a desk all day for a normal job and commute by bike. It boggles my mind when I walk in to a teach a yoga class and the students don’t understand the function of this muscle group. Thanks for the great post.
i love that you addressed the upper body in this post. i often feel that when the iliopsoas is talked about, it becomes a general and very murky conversation about “hip flexors” and the nuances and complications of the functions of the muscles gets very confused and lost! so thank you.
I never really understood the intricacies of the psoas, its placement inside the body, the neighboring muscles it works with and the attachments too! We tend to take for granted the simple movement of lateral hip flexion or the “baby hip lift
the psoas plays a huge part , gets tight and contorted. The YTU balls are a huge therapeutic way to go deep into the body to offer relief to this muscle. Looking forward to the next post!
It really is mesmerizing to learn how the iliosoas act as a connector between lower and upper body movements.
I think it is also worth mentioning the close relationship the PSOAS has to the Quadratus lumborum, a shorter muscle which is also very deep in the core. It runs right alongside the PSAOS major up through the diaphragm. Together they stabilize the spine, determine the health of the relationship between the lower and upper body, AND because of their proximity to the diaphragm and to the gut, they have a strong effect on breathing and digestion. Since breath and healthy digestion directly relate to mental and emotional well being, having a healthy PSOAS and QL is essential to a person’s over all sense of well being, and therefor on their relationships, their enthusiasm about life, their ability to focus on work, and their creativity. You just aren’t going to find many happy thriving people who are shallow breathers with bunchy groins and indigestion.
Thank you for this description of how extensive and important the psoas muscle is for our daily life and activities — I had no idea it played a part in digestion and elimination as well. Great information!
As explained by others, the psoas is attached by its connective tissue to the crura, or lower aspect of the diaphragm. Working with the diaphragm, it acts as a hydraulic pump of sorts to promote deep breathing and increase blood circulation. A limited diaphragm due to various kinds of alignment dysfunction in the body results in a tight psoas. The more limited the diaphragm, the tighter the psoas. Thinking about the psoas from the perspective that the body is one complete system, it is just as effective to work on alignment dysfunction to create more “space” for the diaphragm, for example, postural alignment, as it is to relax or stretch the psoas itself.
Oh, the psoas! As a strength and conditioning coach who primarily utilizes the classic lifts (snatch, clean and jerk), I see lots of tight lower backs in my beginning lifters. After addressing inefficient movement patterns, I suspect (among other things) a restricted psoas. I instruct my athletes who are still tight in the lower back to do lunge stretches with extra emphasis on flexing the knee leading the lunge, comfortably extending the trail leg, and then laterally flexing the spine. This will shift the pelvis forward and allow for a deep stretch of the anterior portion of the hip and subsequently, the psoas. Many of my athletes have remarked how the tension just melts away in their lower backs after this stretch.
I’ve never known the scientific term of psoas, but have discovered on my own that when I stretch the area above my pelvic bone, I typically feel the stretch in my hip. It feels great. Now that I know there is a rhyme to the reason, I look forward to spending more time on this extremely tight area of my body.
Thank you for this wonderful explanation. It is true that we are not aware of this IMPORTANT muscle and the importance of stretcht it. As being a muscle so difficult to perceive it is very important to explian and do exercises that will hepl in daily activities.
I wish I had the anatomy training I’ve been going through with YTU when I was doing triathlons. During long course tris, on the run, I would have shortness of breath and a sensation of having to poop on the run portion. When I would talk to PT friends, they would indicate that it could be my psoas, but only told me to get up in there with my fingers and massage it out. Today we did the hip series on a block and I felt a nice stretch in the psoas that would’ve been quite helpful back in the day!
That is great that you took the time to focus on that mysterious muscle. So many people have heard about it but don’t really know where it is, what it does or how important it is. Your students are lucky to have you!
Dagmar, GREAT article! The psoas muscle is so very integrated with our daily life. Most of us live in a body where the psoas is so incredibly tight and under stretched that we think it is normal.
When a client comes in with a sore lower back and has not had an injury, one of the first things I do is check their flexibility of their psoas! When they are educated on where this muscle lays, where it’s origin is, they have much more understanding on the function of their movement and why I am checking the health of the psoas muscle.
I agree with Courtney, the hip series stretches on the block are amazing for a psoas stretch!