Muscle Minute TUESDAY – The Thigh Spine Connector

I love talking about this muscle. Or maybe it’s more that I find myself talking about it a lot. It is unique in that it is the one muscle I can think of that runs from the back of the body to the front, connecting your lumbar spine to your hip. Let’s jump in…
Origin | transverse processes of T12-L4 |
Insertion | lesser trochanter of the femur |
Action | hip flexion and external rotation; lumbar extension and contralateral rotation |
Innervation | lumbar plexus (L1-3) |
Antagonists | gluteus maximus, rectus abdominus, transverse abdominus |
The Real World Psoas Major
Wait. This muscle does more than just flex the hip? Yes. Way more. In fact, its job as a hip flexor is the least of our worries clinically. People think this muscle becomes tight because we sit a lot, hence placing our hips into chronic flexion. But if this was true, trigger points would be palpated bilaterally. This is rarely the case.
Remember trigger points show up in muscles that are chronically short and if we palpate a psoas major trigger point on one side, this tells us a much different story:
- The hip is chronically externally rotated (think toe-out gait or supinated gait pattern)
- The lumbar spine is rotated to the opposite side, creating facet joint compression
- The pelvis is rotated ipsilaterally (ex: a pelvis rotated to the L will cause compensatory right lumbar rotation and a left psoas trigger point)
- It can make a leg feel shorter (causing compensatory supination of the limb)
This means chronic shortening of this muscle may lead to lower back pain, SI joint problems and overuse issues caused by over supination of a limb, such as ITB friction syndrome, chronic lateral ankle sprains and meniscal irritation.
It is also linked to stress. In just about every yoga reference tightness in this muscle is linked to stress. If anxiety runs high, the psoas runs tight. Do you know what causes a “charley horse” or muscle spasm? It is when you contract a chronically tight muscle in its shortened position.
Let’s say you are like a lot of my patients who walk with one toe turned out or your pelvis rotated to the left, and you have a rough day. It wouldn’t be shocking if your left psoas major developed a trigger point and started giving you back pain.
One more fun fact and I’ll let you go. The psoas major in a cow is also known as tenderloin, or filet mignon. It is not a weight bearing muscle in a cow, so its connective tissue is not toughened by exercise, which is why you pay a premium to eat this succulent cut of meat.
I think we should aim for tender loins ourselves. There is a reason why this is the #1 handout I give to my patients.
Conventional thinking says: Stretch the hip flexors because they are tight
Real World Thinking says: Correct pelvic rotation and lower extremity mechanics and inhibit the hip flexor by activating its antagonists: gluteus maximus, rectus abdominus and transverse abdominus.
Because nobody has time to be in pain.
Until next time…

Kind Regards,
MoveWell Academy
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