(and Its Trusty Sidekick, the Iliacus)
By Karen Roberts, Conversations with Karen
Hi everyone, and welcome back to Conversations with Karen.
Today, we’re diving into one of the most important (and often overlooked) muscle groups in your body—the mighty psoas and its pal, the iliacus. Together, they form what’s called the iliopsoas muscle group, and trust me, this duo deserves your full attention.
What Is the Psoas Muscle and Why Is It So Important?
Let’s start with the psoas.
This long, powerful hip flexor is the only muscle in the body that connects your upper body to your lower body, running from the anterior spine (around belly-button height), through the pelvis, and attaching to a little lip of bone near your hip joint. It helps draw your hip into flexion—basically, it’s what allows you to lift your leg or bring your knee toward your chest.
The psoas is incredibly influential, and not just when it comes to movement. It plays a huge role in posture, stability, and overall mobility. When it’s tight or not functioning properly? It can cause ripple effects throughout the b
ody.
Meet the Iliacus—The Psoas’s Powerful Partner
Now, let’s give a little love to the iliacus, the psoas’s smaller but equally important sidekick. Nestled inside your pelvis, the iliacus helps bring you into a sitting position from lying down. It’s also part of the hip flexor team and works hand-in-hand with the psoas to support movement and core stability.
Common Problems Linked to a Tight or Dysfunctional Psoas
So why am I making such a fuss about this muscle group? Because when the psoas is tight, weak, or neglected, it can cause a whole host of issues. Here’s just a sampling:
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- Low back pain – Unexplained or persistent? Ask your physio to assess your psoas.
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- Pelvic instability – The psoas crosses the pelvis and can affect the sacroiliac joints (those little joints at the base of your spine).
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- Hip joint pain – Because it’s directly attached to the hip, any imbalance can impact the joint’s movement and function.
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- Knee and even ankle pain – Yep, it can reach that far. The psoas connects and interacts with your quadriceps (thigh muscles), which influence the knee—and beyond.
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- Neck tension – Believe it or not, I’ve seen it affect the cervical spine too.
This muscle group is part of your body’s core support system. When it’s functioning well, it absorbs torque, pressure, and tension during dynamic movements like running, squatting, or even walking. When it’s not? Things can get… cranky.
How to Keep Your Iliopsoas Happy and Healthy
The key is keeping this muscle group long, strong, and flexible.
That means:
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- Daily mobility work
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- Stretching (especially hip openers)
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- Functional strength exercises
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- Releasing tension with techniques like breathwork, foam rolling, or targeted bodywork
And most importantly—awareness. Just knowing this muscle exists, and understanding how much it impacts your body, can go a long way.
Final Thoughts: Don’t Sleep on the Psoas
I always tell my clients, ignore the psoas at your peril. If you’ve been dealing with stubborn back pain, tight hips, or unexplained knee or ankle discomfort, it may be time to look a little deeper—literally.
Want to learn more about how to take care of your psoas and iliacus? Check out my full program, The Fix, on my website:
The Fix
Thanks for joining me today. Until next time, keep moving well.
P.S. Interesting in learning more about how to keep your Psoas flexible? Here are some helpful resources:
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- Read our Special Report, 5 Common Everyday Mistakes Leading to Chronic Pain & Dysfunction Leading to Chronic Pain & Dysfunction
