Understanding psoas syndrome

The psoas (pronounced so-az) muscles are a pair of deep muscles located in the lower back. These long, spindle-shaped muscles run on both sides of the spine, from the lower back down to the top of the thigh bone (femur). The function of the psoas muscles is to connect the upper body to the lower body, assisting in movements like hip flexion and torso bending. They play a vital role in core stability and mobility.¹

When these muscles become irritated or injured, it's referred to as psoas syndrome. This condition is rare, often misdiagnosed, and commonly observed in athletes such as runners, high jumpers, or dancers due to trauma or overuse of the hips.²

Psoas diagnosis

History taking: the symptoms

You will first notice symptoms of a disease when you feel something unusual in your body. The symptoms of psoas syndrome include:

• Back pain in the lumbosacral area (between the bottom of your spine and the buttocks)
• Pain in the gluteal area (your buttocks)
• Groin pain (the area where the abdomen ends and the legs begin)
• Pelvic pain
• Stiffness of the back

Pain typically intensifies when transitioning between positions, like sitting to standing, and often improves with rest. This discomfort may also radiate down to the thigh and knee and possibly cause a limp or a shuffling gait.^2,3

Physical examination

To identify pain and weakness associated with psoas syndrome, your doctor will conduct a thorough physical examination, assessing motion and muscle strength in specific areas such as your hips, legs, and spine. During this examination, you may feel a sensation of slipping or catching in the groin when your knee is flexed to 90 degrees.

Tenderness may also be present when the examiner palpates the psoas muscle insertion site, and a reduced range of motion, particularly in leg extension, may be observed. Additionally, your doctor will perform leg extension and hip flexion tests. 

Throughout the examination, it's important to communicate any pain or other sensations experienced during the tests, as this feedback is crucial for confirming the diagnosis or ruling out other conditions with similar symptoms.^2,5

Imaging 

• X-ray of the hip: Although it's often negative and generally not very helpful in diagnosing psoas syndrome, it may be used to rule out other differential diagnoses
• Ultrasound: This tool can be helpful, particularly in evaluating the origins of hip pain. It can also visualise the muscle and identify any abnormalities or guide certain confirmatory interventions, such as lidocaine injection
• Magnetic resonance imaging (MRI): MRI can reveal the structure of the muscle, detecting any enlargement, thickening, or other abnormalities²

Other similar conditions

Psoas syndrome is frequently misdiagnosed due to its similarity to other conditions with comparable symptoms. When diagnosing psoas syndrome, your healthcare provider will rule out these issues, such as:

• Herniatic disc of the lumbar region
• Arthritis of the hip
• Hip impingement
• Femoral bursitis
• Snapping hip syndrome
• Visceral pain (appendicitis, diverticulitis, prostatitis, salpingitis, kidney stone, and colon cancer)²

Treatment

Treatment of psoas syndrome depends on the cause of the injury and its severity. Generally, the treatment involves conservative management, physical therapy to stretch and strengthen the muscle, and, in some cases, more advanced interventions.

Conservative management

• Take a break and rest from activities that can aggravate the pain, such as those requiring repetitive hip flexion or prolonged sitting
• Modify your exercise routine to avoid overuse of your psoas muscle. Consider incorporating low-impact activities such as swimming and cycling
• To help manage the pain, you can use over-the-counter pain relievers such as NSAIDs (ibuprofen) and acetaminophen²

Physical therapy

The goals of physical therapy in managing psoas syndrome are:

• Strengthen your core and surrounding muscles, such as the transversus abdominis and pelvic floor, to prevent overuse of the psoas muscle
• Improve flexibility and range of motion (ROM) in your hips and spine

During physical therapy, your therapist will stretch and exercise your hips, spine, and psoas muscles. You may also be prescribed regular exercises to achieve treatment goals. These exercises may include:

• Passive stretch
• Forward lunge stretch
• Straight leg raise
• Standing hip flexion
• Hip extension
• Side-lying leg lifts
• Mini squats^4,5,6

Osteopathic manipulative treatment (OMT)

This treatment approach utilises techniques to address dysfunction or imbalance of the psoas muscle and associated musculoskeletal issues. It is beneficial for treating iliopsoas muscle dysfunction, including psoas syndrome. Compared to surgical treatment or corticosteroid injections, this option has fewer complications. OMT aims to decrease pain, improve range of motion, and restore function of the neuromusculoskeletal system. The modalities of this treatment include:

• Muscle Energy Techniques (METs): This direct technique involves placing the muscle and joint into a restrictive barrier and then asking the patient to push against resistance with the tight muscle (contracting the dysfunctional muscle). Afterwards, the muscle is relaxed, and the provider moves the tight area further into the restrictive barrier. This procedure usually will be repeated three to five times
• Counterstrain (CS): This indirect technique involves localising the tender point and moving it into a more comfortable position for 90 seconds while monitoring for pain reduction and changes in the tender spot's texture. Then, the muscle or joint returns to the neutral position, and the tender spot is released. This helps reduce hypersensitivity and improve proprioception⁶

Other advanced interventions

In cases where conservative and other treatment approaches fail to provide relief, corticosteroid injections or surgical intervention may be considered as alternative options.²

FAQs

How is psoas syndrome treated?

Psoas syndrome treatment involves:²

• Physical therapy that focuses on stretching and strengthening the spine, hip joints, and psoas muscle
• Pain relief such as ibuprofen and acetaminophen
• Home exercise
• Osteopathic manipulative therapy (OMT)
• Corticosteroid injections
• Surgical interventions

What medication is used for psoas pain?

You can use over-the-counter pain relievers such as NSAIDs (ibuprofen) and acetaminophen (paracetamol) to reduce the pain associated with this syndrome.

Another option, considered by doctors if conservative treatment fails, is corticosteroid medication. This may be injected into your psoas muscle, typically guided by ultrasound.²

What are the risks of cortisone injections in the hip?

Corticosteroid injections, including cortisone, are anti-inflammatory medicines commonly used to treat various conditions such as joint pain, arthritis, and sciatica. However, like other treatment approaches, they carry risks and potential side effects, including:

• Pain, discomfort, or temporary bruising at the injection site
• Changes to vision, such as blurred vision
• Risk of infection leading to redness, swelling, and pain at the injection site
• Damage to surrounding tissues, though this is unlikely with skilled healthcare professionals
• Loss of fat at the injection site, resulting in permanent dimples
• Some studies suggest a risk of progression of osteoarthritis and new avascular necrosis^7,8,9

What are the symptoms of an inflamed psoas?

• Pain in your pelvis, groin, and gluteal area 
• Pain that radiates to your knee
• Lower back pain
• Pain that aggregates with a change of positions such as from sitting to standing
• Difficulty in walking that can cause limp and shuffle walk^2,3

What is a malignant psoas syndrome?

It is a rare and serious condition that occurs when advanced-stage malignancy (cancer) spreads to the psoas muscle. Individuals with this condition may experience painful hip flexion, loss of mobility, and intense pain in the legs and back, significantly impacting their quality of life. 

Common causes include lung cancer, kidney cancer, lymphoma, colorectal cancer, cervical cancer, and uterine cancer. 

Treatment involves managing the cancer itself, which depends on the specific type and stage of the cancer, as well as pain management to help reduce pain and improve mobility.^10,11

Summary

Psoas syndrome refers to irritation or injury in the psoas muscle, which plays a crucial role in connecting your torso and lower body. These muscles extend from both sides of your lower spine to your upper thigh bone (femur) and are essential for posture stability, hip flexion, and overall movement of your lower back, hips, and pelvis. 

Diagnosing this syndrome typically involves:

• History taking. Symptoms include lower back, buttock, pelvic, groin, and radiating pain to the knee. Symptoms may worsen with movement, such as transitioning from sitting to standing, and may result in limping or shuffling walk
• Physical examination to assess muscle strength, range of motion, and tenderness in the affected area
• Imaging tests such as ultrasound or MRI to confirm the diagnosis and assess the extent of the injury

Treatment modalities for psoas syndrome include:

• Conservative treatment: rest, activity modification, and pain relief medications to alleviate symptoms
• Physical therapy and home exercises: improve muscle strength, flexibility, and overall function
• Osteopathic manipulative therapy (OMT): involves hands-on techniques to address muscle imbalances and restore proper function
• Advanced interventions: corticosteroid injections into the psoas muscle, guided by ultrasound, or surgical interventions in severe cases

Overall, a multidisciplinary approach is often used to effectively manage psoas syndrome and improve the patient's quality of life.