What Causes Psoas and Deep Hip Flexor Pain?
Pain in the psoas major muscle usually comes from overuse, sitting for long periods, or an alignment problem in the pelvis and lower spine. The psoas links your lumbar vertebrae to your thigh bone. So when this deep hip flexor is tight or irritated, it can refer pain to the groin, the front of the hip or the lower back. Standing whole-body imaging helps show the alignment problems that keep the muscle under strain.
Key takeaways
- The psoas major is the deepest hip flexor. It runs from the lumbar spine to the top of the thigh bone.
- Deep hip flexor pain is commonly felt in the groin, the front of the hip or the lower back, and it often gets worse after sitting.
- The alignment of your pelvis and the posture of your lower spine directly affect how hard the psoas has to work.
- Scans taken lying down relax the muscle and may hide the alignment load that drives symptoms.
- A standing EOS scan images the full chain from spine to hips while you carry your real body weight.
What is the psoas muscle and why does it matter?
The psoas major is a thick, deep muscle. It runs from the sides of your lumbar vertebrae, through the pelvis, and attaches to the lesser trochanter near the top of your thigh bone (femur). Together with the iliacus muscle, which lines the inside of the pelvis, it forms the iliopsoas. This is the body's most powerful hip flexor.
Because it links the spine and the leg, the psoas plays a part in almost every movement you make: walking, climbing stairs, getting up from a chair and holding an upright posture. When it works well, you hardly notice it. When it is irritated, tight or overloaded, the pain it causes can spread surprisingly widely.
What does psoas muscle pain feel like?
Psoas muscle pain often looks like other conditions, which is why it is often misdiagnosed. The discomfort tends to be deep rather than near the surface, and it can move between several areas.
A note about nerve symptoms. If you develop sudden numbness, weakness in the leg, or loss of bladder or bowel control along with hip or back pain, get urgent medical help. Contact your doctor straight away or go to the nearest emergency department. These symptoms need to be checked immediately.
What causes psoas major muscle pain?
Several things can overload or irritate the psoas. Often more than one is involved at the same time.
An important point is that the body works as a connected chain. A problem in the lumbar spine, a difference in leg length or a rotated pelvis can all change how the psoas is loaded. The pain you feel in the groin or hip may actually be driven by misalignment somewhere else. This is why looking at the whole picture matters.
How does a standing scan help with deep hip flexor pain?
A standing scan shows your skeleton while it carries your real body weight, exactly the conditions that put stress on the psoas. When you lie down for a usual X-ray, CT or MRI, gravity is taken away and the muscles relax. The pelvis settles into a neutral position that may not reflect how you actually stand and move.
You stand naturally inside the EOS scanner. The image captures your spine, pelvis, hips and legs in one view, and shows how each area relates to the others. Pelvic tilt, a difference in leg length and compensating curves all become visible. The scan uses about 90% less radiation than a standard X-ray, around ten times less.
Imaging done lying down relaxes the psoas and flattens the curve of the lower back. A tilt or rotation of the pelvis that loads the muscle all day may look normal when gravity is taken away. Scans of single areas also miss how the spine, pelvis and legs work together as a chain.
ScanAlign standing EOS imaging captures the full picture, so your clinician can see exactly what is pulling on the psoas and why. If the irritation is linked to iliopsoas bursitis, a swollen fluid sac next to the tendon, the alignment data helps explain why the bursa is under pressure in the first place.
When MRI is the better choice. EOS shows bones, joints and alignment very well. For soft tissue detail, such as the psoas tendon itself, discs or nerves, MRI is usually the better tool. Your consultant may recommend both to build a complete picture.
What helps manage psoas muscle pain?
Treatment depends on the underlying cause, and your clinician will decide this after a proper assessment. A few general approaches are worth knowing about.
- Graduated loading. Current evidence favours gradually strengthening the hip flexors over passive stretching alone. A psoas stretch may ease discomfort in the short term, but loading the muscle under guidance tends to bring longer-lasting change.
- Posture and movement habits. Breaking up long periods of sitting, adjusting the height of your desk and varying your movement through the day all reduce the constant shortening of the psoas.
- Alignment assessment. Finding the structural factors, such as a pelvic tilt or a problem with the lumbar curve, gives a clinician the information they need to plan targeted rehabilitation instead of guesswork.
Be careful with claims that deep massage or manual psoas release brings lasting fixes on its own. The psoas sits behind the abdominal organs and is hard to reach directly. Real improvement usually comes from understanding and correcting the alignment and movement patterns that overload it.
Before you start treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in your pelvis, your legs or your spine changes what will actually help.
Wondering whether your psoas pain is linked to how your pelvis and spine are aligned? A free video consultation can help you decide if travelling to London for a standing scan is the right next step.
Book a free video consultationFrequently asked questions about psoas pain
Most people feel it as a deep ache in the groin or at the front of the hip. It can also refer to the lower back or the front of the thigh, because the muscle spans all three areas.
Yes. The psoas attaches directly to the lumbar vertebrae. When the muscle shortens or tightens, it can pull the lower spine forward into a deeper curve, which may cause back pain.
Not quite. Psoas pain is a general term for discomfort from the muscle itself. Iliopsoas tendinopathy means irritation or degeneration of the tendon where the combined iliopsoas attaches to the thigh bone. The two often overlap.
A psoas stretch can give temporary relief, but current thinking favours graduated loading and strengthening along with stretching. If an alignment problem is driving the tightness, stretching alone may not address the root cause.
The Thomas test is a clinical examination. You lie on the edge of an examination couch and pull one knee to your chest. If the other thigh lifts off the couch, it suggests the hip flexor on that side is tight. It is a useful screening tool, but it does not explain why the muscle is tight.
Yes. In some cases the psoas tendon can catch against the edge of the acetabular cup (the socket component). This is sometimes called psoas impingement. It typically causes deep groin pain during activities that bend the hip.
An EOS scan captures your skeleton while you stand, using about 90% less radiation than a standard X-ray, around ten times less. It images the full body in one pass, so clinicians can see how the spine, pelvis and legs line up under real load.
No. You can refer yourself. The process starts with a free video consultation, where we discuss your symptoms and confirm whether a standing scan is suitable for you.
The price for patients travelling from abroad is confirmed during your free video consultation, which you can arrange through our book a hip and pelvis scan page.
Yes. The EOS system uses about 90% less radiation than a standard X-ray, around ten times less. It is widely used in orthopaedic centres around the world and is considered very low dose.
Understand what is driving your psoas pain
A free video consultation with our specialist radiographer helps you decide whether standing whole-body imaging in London is the right next step for you.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- Andersson, E. et al. "The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip." Scandinavian Journal of Medicine & Science in Sports, 1995.
- Domb, B.G. et al. "Iliopsoas impingement: a newly identified cause of labral pathology in the hip." HSS Journal, 2011.
- NHS. "Hip pain in adults." nhs.uk. Accessed 2024.
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.