Ischiofemoral Impingement: A Hidden Cause of Buttock Pain

Buttock pain is complex, with many causes — sciatica, sacroiliac joint arthritis, piriformis syndrome, and hamstring tendonitis among them. A less common cause is ischiofemoral impingement, where abnormal contact between the thigh bone (femur) and the pelvic bone pinches the muscle between them, causing buttock pain. So what is ischiofemoral impingement, what are its symptoms, and is an ischiofemoral impingement injection an option?

Ischiofemoral impingement is one of several causes of deep buttock pain we assess.

What is the ischiofemoral space?

picture of buttoch with arrow pointing to ischiofemoral space

The ischiofemoral space sits between the upper part of the femur (the lesser trochanter) and the lower part of the pelvic bone (the ischium). The quadratus femoris muscle runs through this space and, with the other buttock muscles, rotates the hip outwards. In some people, the space is too narrow, so the bones pinch the muscle, causing swelling and pain.

Symptoms of ischiofemoral impingement

People with ischiofemoral impingement usually develop buttock pain. The pain often spreads to the hip, groin, or back of the thigh, and is typically worse when sitting. Some people feel a hip snapping when taking a long stride or rotating the hip outwards.

The condition is more common in middle-aged women than men, and dancers and rowers are particularly at risk. People sometimes have more than one problem at once, such as piriformis syndrome or high hamstring tendonitis.

On examination, the doctor looks for signs of pinching at the back of the hip. Pressing on the quadratus femoris muscle is often sore, and moving the hip into flexion and internal rotation usually reproduces the buttock pain.

The ischiofemoral impingement test

We use a simple test with the person lying face down and the hip stretched, then rotated inwards and outwards. A positive test reproduces the buttock pain — though this test can also be positive in other conditions, such as piriformis syndrome, so it isn’t diagnostic on its own.

Imaging for ischiofemoral impingement

We use imaging to confirm the diagnosis and rule out other causes. An MRI of the buttock is our first choice. In ischiofemoral impingement, it shows swelling in the quadratus femoris muscle — brighter than the surrounding tissue — and often a narrowed space between the pelvis and the femur. In more severe cases, the muscle shrinks. Sometimes there’s a coexisting problem, such as high hamstring tendonitis, that further narrows the space.

Ischiofemoral impingement treatment

We try simple treatments before more invasive ones, and recent studies suggest most cases resolve without surgery.

Treatment usually starts with physiotherapy aimed at improving the strength and stability of the hip and pelvis, focusing on the hip rotators and the posterior chain. Useful exercises include single-leg squats, theraband crab walks, side leg raises, lunges, hip thrusters, and Bulgarian squats. Soft-tissue release and joint mobilisation of the hip and lumbar spine can also improve pelvic movement and reduce pinching of the quadratus femoris.

If simple treatment fails, an ultrasound-guided cortisone injection into the quadratus femoris can help (covered below).

Surgery is reserved for cases that fail everything else. It aims to open the ischiofemoral space and reduce pressure on the muscle, usually by keyhole decompression. But results aren’t guaranteed, and risks include infection, nerve damage, and persistent pain — so it’s a last resort.

More about the ischiofemoral impingement injection

Injecting cortisone into the quadratus femoris muscle reduces swelling and pinching. We use ultrasound guidance to place the needle accurately in the muscle and avoid nearby structures such as the sciatic nerve. The risks of cortisone are minimal — mainly a small chance of infection and a temporary flare lasting up to a week. So an ischiofemoral impingement injection is a genuine option for cases that don’t settle with rehab.

Do you need a CT scan for an ischiofemoral impingement injection?

No. Ultrasound clearly shows the quadratus femoris muscle, and an experienced practitioner can place a needle into it accurately. Ultrasound is also much cheaper and avoids the high radiation dose of a CT-guided injection.

Frequently asked questions about ischiofemoral impingement.

What are the main symptoms of ischiofemoral impingement?

Buttock pain that’s often worse with sitting and can spread to the hip, groin, or back of the thigh. Some people feel a snapping in the hip with long strides or outward rotation. It’s most common in middle-aged women, and in dancers and rowers.

How is ischiofemoral impingement diagnosed?

From the pattern of pain and a clinical examination (tenderness over the quadratus femoris, pain on hip flexion and internal rotation), confirmed with an MRI showing swelling in the muscle and a narrowed ischiofemoral space. Imaging also rules out other causes of buttock pain.

Does an ischiofemoral impingement injection work?

For many people, yes. An ultrasound-guided cortisone injection into the quadratus femoris reduces the swelling and pinching, easing pain so you can progress with rehab. It’s used when simple treatments haven’t worked.

Is ischiofemoral impingement the same as piriformis syndrome?

No, though they can feel similar and even coexist. Both cause deep buttock pain, and the clinical tests overlap — which is why an MRI matters. Piriformis syndrome involves a different muscle compressing the sciatic nerve, whereas ischiofemoral impingement is pinching of the quadratus femoris between two bones.

Can ischiofemoral impingement be cured without surgery?

Usually, yes. Most cases settle with physiotherapy focused on hip and pelvic strength, sometimes with an ultrasound-guided cortisone injection. Surgery is reserved for the few cases that fail all other treatment.

Why is it more common in women?

The exact reason isn’t certain, but differences in pelvic shape and the width of the ischiofemoral space are thought to make pinching more likely, which is also why it’s seen in activities with extreme hip movement, such as dance and rowing.

Final word from Sport Doctor London about ischiofemoral impingement

Ischiofemoral impingement is an uncommon cause of buttock pain, so it’s essential to rule out other causes such as sciatica, hamstring tendonitis, and sacroiliac joint arthritis. The good news is that simple treatments — physiotherapy and an ultrasound-guided cortisone injection — are usually effective.

To book a one-stop buttock and hip assessment with Dr Masci in London, contact the team here or call +44 (0) 203 488 0350.

Related conditions:

Click on the image below to find out more about possible causes of hip and groin pain

picture of hip and buttock of young lady