Psoas Muscle: Location, Function, Injuries and Care
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is the psoas muscle?
The psoas is a long, ribbon-shaped core muscle on each side of your lower spine. It runs from below the ribs, through the pelvis, to the top of the thigh bone (femur). With the iliacus, it forms the iliopsoas group. It steadies your posture, moves your hips and lifts your legs. Injuries are uncommon, and imaging can help check concerns. [1]
What the research says
The psoas minor is not present in everyone. In a cadaver study of 10 bodies, a psoas minor was present in 6 (60%); the authors note that reported frequencies in other populations range from 36.7% (Indian) to 65.6% (US), and that only the psoas major is present in all individuals (Dragieva et al., Cureus, 2018). [2]
Low-back pain usually improves fastest in the first weeks. A meta-analysis of 33 cohorts (11,166 participants) found that average pain scores in acute low-back pain fell from 52 to 23 (out of 100) by 6 weeks and to 6 by 52 weeks, while persistent pain fell more slowly (51 to 33 at 6 weeks and 23 at 52 weeks). This describes average courses and is not a reason to delay evaluation of severe or worsening symptoms (Menezes Costa et al., Canadian Medical Association Journal, 2012). [3]
Exercise therapy reduced chronic low-back pain compared with no treatment or usual care. A Cochrane review of 249 trials found moderate-certainty evidence that exercise lowered pain by 15.2 points on a 0–100 scale at earliest follow-up (95% CI −18.3 to −12.2), a clinically important difference; the improvement in function (−6.8 points) was smaller and did not meet the review’s threshold (Hayden et al., Cochrane Database of Systematic Reviews, 2021). [4]
What is the psoas muscle?
This long, ribbon-shaped muscle sits in your lower back, also called the lumbar region. It is one of the core muscles in your abdomen. [1]
You have one on each side of your spine. Together, they link your spine to your lower body. They help your belly, pelvis and legs move together. [1]
The muscle lies deep inside your body. Lower-back and hip pain can come from many muscles, nerves, joints or nearby organs. So symptoms alone do not point to a problem in this muscle.
Where is the psoas muscle located?
Each one starts in your lower back, just below the ribs. It runs beside the spine and passes through the pelvis. It ends in the groin near the hip, on a small bump at the top of the thigh bone (femur) called the lesser trochanter. [1]
With the iliacus muscles in the hip, it forms the iliopsoas muscle group. Because it sits so deep, it lies close to the lower spine, hip joints, nerves and several digestive organs. [1]
Location or connection | Description |
Upper attachment | Begins in the lower back just below the ribs |
Course | Runs alongside the spine through the pelvis |
Lower endpoint | Ends on the lesser trochanter, at the top of the femur near the hip |
Muscle group | Joins the iliacus muscles to form the iliopsoas group |
Nearby structures | Close to the lumbar spine, hip region, nerves and digestive organs |
What does the psoas muscle do?
This muscle links your spine to your lower body. It acts like a bridge between deep muscles and parts closer to the skin. This helps your belly and legs work together when you move. [1]
It works with other muscles to steady your posture and move your hips and upper legs. It holds your lower back steady when you sit. It helps lift your trunk up when you sit up from lying on your back. It also bends your hips, lifts your thighs and keeps the top of the thigh bone steady as your hip moves. [1]
Function | Everyday example |
Postural stability | Helps hold the lower back still while sitting |
Trunk movement | Helps pull the trunk upward from lying on your back, as in a sit-up |
Hip flexion | Helps move the hips while standing or lying down |
Leg lifting | Helps lift the upper legs for walking and climbing stairs |
Hip-joint support | Helps stabilize the top of the femur while the hips move |
It does not work alone. Your movement and posture depend on muscles, joints, nerves and the spine working together.
What is the anatomy of the psoas muscle?
Like other muscles, it is made of thousands of tiny fibers woven together. These fibers stretch and squeeze to move your lower back, hips and legs. [1]
In most adults, this muscle is about 16 inches long and slightly triangular. The upper part, in the lower back, is thinner and narrower. The lower part, near the hips, is wider. [1]
Nerves from the lower spine connect to the muscle and give it feeling. It is also linked to the femoral nerves. These nerves give feeling to your thighs and the quadriceps muscles. [1]
Anatomic feature | Description |
Shape | Slightly triangular |
Upper portion | Thinner and narrower in the lower back |
Lower portion | Wider where it connects near the hips |
Typical adult length | Around 16 inches |
Nerve connections | Lumbar-spine nerves and femoral nerves |
Length and shape vary from person to person. A measurement cannot tell you if the muscle is hurt or healthy.
What is the iliopsoas muscle group?
These muscles join the iliacus muscles in the hip to form the iliopsoas muscle group. This group links your lower spine and pelvis to hip movement. [1]
The iliopsoas helps bend the hip and bring the upper leg toward the body. Pain here can come from the psoas, iliacus, hip joint, nerves, spine or another nearby part. A doctor may need to check it.
What can irritate or injure the psoas muscle?
Injuries to this muscle are uncommon because it sits deep inside the body. Athletes in sports that put a lot of force on the core or hips may get hurt here more often. These injuries are often strains. [1]
Psoas syndrome is a rare condition that happens when the muscle is irritated. It can happen with no clear cause. Its symptoms can look like more common problems, such as arthritis or sacroiliitis. [1]
Your lower back and hip area is a busy network of muscles, nerves and joints. So it is hard to tell from symptoms alone what is causing pain or stiffness.
Possible contributor | How it relates to the muscle |
Muscle strain | May follow forceful core or hip activity, especially in some sports |
Muscle irritation | May contribute to psoas syndrome |
Nearby joint or spine condition | Arthritis or sacroiliitis can create overlapping symptoms |
Digestive-organ condition | Conditions nearby may irritate the muscle |
Nerve or muscle involvement | Can make the cause of pain or stiffness harder to identify |
Can digestive conditions affect the psoas?
These muscles run over or near many digestive organs. Problems in those organs may also irritate them. [1]
Examples include Crohn’s disease, irritable bowel syndrome, diverticulitis, a perforated colon and colorectal cancer. Gut symptoms or lower-back pain do not prove a problem in this muscle. They just mean the nearby anatomy can make diagnosis harder. [1]
What symptoms can occur with psoas problems?
Symptoms may include lower-back pain, stiffness or discomfort around the hips and upper legs. These symptoms overlap with other conditions. So where the pain is, or how it feels, does not prove the cause.
See a doctor if back pain, stiffness or other symptoms do not get better after about a week. Tell them when your symptoms began and what you were doing at the time. [1]
Symptom or pattern | Why evaluation may help |
Lower-back pain | Can come from this muscle, the spine, joints, nerves or other structures |
Stiffness | May occur with muscle, joint or spine conditions |
Hip or upper-leg discomfort | Can involve this muscle, the iliopsoas group, hip or nerves |
Pain after forceful activity | May raise the possibility of a strain but does not confirm one |
Symptoms lasting about a week or longer | Persistent symptoms deserve professional assessment |
Get medical care quickly if you have sudden severe pain, new weakness or numbness, loss of bladder or bowel control, fever, or symptoms that get worse fast. These signs can have many causes. They do not by themselves point to a muscle problem.
How are psoas problems diagnosed?
A doctor may examine your back and hips. They may ask when your pain, stiffness or other symptoms started and what you were doing then.
Other tests may include MRI, electromyography (EMG) or ultrasound. The right test depends on your symptoms, the exam findings and what your doctor wants to find out. [1]
Evaluation | What it can contribute |
Physical exam | Examines the back and hips and considers movement and symptoms |
MRI | Shows these muscles and the surrounding area |
Electromyography | May help evaluate nerve and muscle function |
Ultrasound | May provide images of the muscle and nearby tissues |
A scan result does not prove what is causing your pain. Your doctor reads it together with your exam and history.
How are psoas injuries treated?
Treatment depends on what is causing pain or other symptoms in or around this muscle. A minor strain may need rest, or a break from hard activity for a few weeks.
Your doctor may suggest physical therapy. A physical therapist can give you stretches and exercises to strengthen the muscle and make it more flexible. [1]
If another health problem affects this region, treatment focuses on that problem. Do not use a general stretch, massage or exercise plan in place of a proper check-up.
Treatment approach | When it may be considered |
Rest or activity modification | May be used for a minor strain, including avoiding intense activity for a few weeks |
Physical therapy | Can guide stretches and exercises for strength and flexibility |
Treatment of another condition | Used when a spine, joint, nerve or digestive condition affects the area |
Follow-up | Helps assess whether symptoms are improving or need further evaluation |
How can someone care for the psoas muscles?
Stretching and warming up before exercise can help prevent muscle injuries. Better flexibility and core strength can also help protect this muscle. [1]
Build up activity slowly. Avoid sudden jumps in how hard or how often you train.
General care measure | Practical approach |
Warm up | Prepare the body before exercise or demanding activity |
Improve flexibility | Use a gradual, appropriate approach rather than forcing a stretch |
Build core strength and stability | Strengthen with guidance when pain or injury is present |
Increase activity gradually | Avoid abrupt increases in intensity or frequency |
Take movement breaks | Change position instead of sitting or standing in one place for a long time |
The safest exercise, stretch or posture plan is different for each person. If you have pain, ask a doctor or physical therapist which movements are right for you.
What position relaxes the psoas?
A safe, neutral posture can help keep this muscle relaxed. Keep your head above your shoulders and your shoulders above your hips. When sitting, bend your knees to about 90 degrees, keep your feet flat on the floor and keep your ankles apart. When standing, keep your feet hip-width apart. [1]
Avoid sitting or standing in one position for a long time. If you sit at work, get up and walk around now and then. If you stand at work, take regular breaks to sit down. [1]
Do not try to diagnose or treat muscle pain at home based on posture alone. A doctor or physical therapist can suggest the right positions, stretches and strength exercises.
Is walking good for the psoas muscle?
Walking can help your body relax and return to a neutral posture, especially after you sit still for a long time. Short walks during the day may keep your body relaxed and prevent some common aches and pains. [1]
Walking does not fix every kind of pain here. Stop and get advice if walking makes symptoms worse. Also get help if pain is severe, lasts, or comes with weakness, numbness, fever or loss of bladder or bowel control.
What is the psoas major versus psoas minor?
The terms “psoas” and “psoas major” mean the same thing. About two in three people also have psoas minor muscles. These sit on top of the larger muscle and connect to the iliopsoas in the pelvis. [1]
About one in three people do not have them. In these people, the body naturally breaks down the muscle tissue and turns it into another kind of supportive tissue. Not having one is normal and does not raise the risk of injury or health problems. [1]
Having or lacking this smaller muscle is not a measure of fitness, flexibility or health.
What questions should you ask about psoas muscle symptoms?
Good questions cover where the pain may come from, whether a scan would help, which activities to pause, safe exercises and which symptoms need urgent care.
Could my lower-back or hip symptoms come from a muscle, nerve, joint, spine or nearby organ?
What details about when the symptoms began and what I was doing may help with evaluation?
Is a physical exam enough, or would MRI, EMG or ultrasound be useful?
Could a strain, psoas syndrome, arthritis or sacroiliitis be contributing to symptoms?
Could a digestive-system condition be irritating the area?
Which activities should I pause while symptoms are being assessed?
Would physical therapy be appropriate?
Which stretches or strengthening exercises are safe for me?
How should I increase activity gradually?
Which symptoms should prompt urgent or emergency care?
Conclusion
The psoas is a deep, ribbon-shaped core muscle. It runs from the lower back, through the pelvis, to the top of the thigh bone near the hip. You have one on each side of your spine. Together with other muscles, they support your posture, move your hips and lift your legs. [1]
Injuries are uncommon. But strains, muscle irritation, joint or spine problems and digestive conditions can all cause similar symptoms. A physical exam, MRI, EMG or ultrasound may help show what is going on. Treatment depends on the cause. [1]
Warming up, staying flexible, building core strength, taking movement breaks and adding activity slowly may support muscle health. See a doctor if lower-back pain, stiffness or other symptoms last about a week. Get help right away if symptoms are sudden, severe or getting worse fast. [1]
Want a clearer next step for lower-back and movement questions? Read more health articles before speaking with a healthcare professional. [1]
Frequently Asked Questions
What is the psoas muscle?
The psoas is a long, ribbon-shaped core muscle in your lower back. You have one on each side of your spine. Together, they help move your lower back, hips and upper legs.
Where is the psoas muscle located?
The muscle starts in your lower back, just below the ribs. From there, it runs beside the spine, through the pelvis, and ends at the top of the thigh bone near the hip.
What does the psoas muscle do?
The muscle steadies your posture and holds your lower back still when you sit. It also bends your hips, lifts your upper legs when you walk or climb stairs, and keeps the top of the thigh bone steady as your hip moves.
Is the psoas part of the core?
Yes. The muscle is one of the core muscles in your abdomen. It links your spine and lower body and helps your trunk and legs move together.
Is a psoas injury common?
Injuries here are rare because the muscles sit deep inside the body. Athletes in sports that put a lot of force on the core or hips may have a higher chance of a strain.
What is psoas syndrome?
Psoas syndrome is a rare condition where this muscle gets irritated. It can happen with no clear cause. It can look like arthritis, sacroiliitis or other causes of lower-back and hip symptoms.
What does a psoas strain feel like?
A strain in this muscle may cause lower-back, hip or upper-leg symptoms. But these symptoms overlap with many other conditions. If your pain lasts or gets worse, see a doctor instead of guessing from symptoms.
Does an MRI show the psoas muscle?
Yes. MRI can show these muscles and the parts around them. EMG or ultrasound may also be used, depending on what your doctor needs to check.
How are psoas problems treated?
Treatment depends on the cause. A minor strain may need rest or a break from hard activity for a few weeks. Physical therapy can teach you stretches and strength exercises. Other conditions in the area need their own treatment.
What is the best position for the psoas?
A safe, neutral posture usually helps. Keep your head above your shoulders and your shoulders above your hips. When sitting, bend your knees to about 90 degrees and keep your feet flat. When standing, keep your feet hip-width apart. If you have pain, a doctor or physical therapist can suggest specific positions.
Is walking good for the psoas?
Walking can help your body return to a neutral posture after you sit still for a long time. Walking does not treat every problem, so get worsening or severe symptoms checked.
Do all people have a psoas minor muscle?
No. About two in three people have one. Not having one is normal and does not raise the risk of injury or health problems.
When should someone seek care for psoas symptoms?
See a doctor if back pain, stiffness or related symptoms last about a week. Get care quickly for sudden severe pain, new weakness or numbness, loss of bladder or bowel control, fever or symptoms that get worse fast.
Related Reading
Groin Strain: What It Is, Why It Happens, and How to Heal explains pulled muscles in the groin and how they heal.
Understanding Lower Back Pain: Causes, Symptoms, and Solutions covers common causes of low back pain and treatment options.
Sacroiliitis: Complete Guide to the Joint Pain Often Mistaken for Low Back Pain explains inflammation of the joint where the spine meets the pelvis.
Crohn's Disease: Symptoms, Causes, Flares vs. Remission and Treatment — What You Need to Know explains a bowel disease that can irritate nearby muscles like the psoas.
References
Cleveland Clinic. Psoas Muscle: What It Is, Where It Is & Anatomy. Cleveland Clinic. Last updated February 9, 2024. https://my.clevelandclinic.org/health/body/psoas-muscle
Dragieva P, Zaharieva M, Kozhuharov Y, et al. Psoas minor muscle: a cadaveric morphometric study. Cureus. 2018;10(4):e2447. PMID 29888151. https://doi.org/10.7759/cureus.2447
da C Menezes Costa L, Maher CG, Hancock MJ, et al. The prognosis of acute and persistent low-back pain: a meta-analysis. CMAJ. 2012;184(11):E613-E624. PMID 22586331. https://doi.org/10.1503/cmaj.111271
Hayden JA, Ellis J, Ogilvie R, et al. Exercise therapy for chronic low back pain. Cochrane Database Syst Rev. 2021;9(9):CD009790. PMID 34580864. https://doi.org/10.1002/14651858.CD009790.pub2
Centers for Disease Control and Prevention. Physical Activity Basics and Your Health. CDC. Accessed October 30, 2026. https://www.cdc.gov/physical-activity-basics/about/index.html
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition.
It explains psoas location, function, anatomy, the iliopsoas group, possible injuries and irritation, nearby digestive conditions, evaluation, treatment, posture, walking, prevention and psoas minor variation. It does not diagnose a psoas strain, psoas syndrome, back condition, nerve problem or digestive disease.
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