Ischiofemoral impingement: when two bones nearly touch and the pain has its own agenda.

A narrow gap on MRI is only half a diagnosis. If your deep hip pain has outlived its treatment, the nervous system deserves a look.

This page is about understanding the condition and the role the brain and nervous system can play in it. It is not a diagnosis. Your own clinicians know your case.

What ischiofemoral impingement is

Behind and below the hip joint, the top of the thigh bone has a small bony knob called the lesser trochanter. Nearby is the ischium, the sitting bone of the pelvis. Normally there is a comfortable gap between them, and a small muscle, the quadratus femoris, runs across it. In ischiofemoral impingement that gap is narrow, and with certain movements, especially extending the hip, turning the leg outward or taking a long stride, the two bones pinch the muscle between them.

The result is a deep, aching pain in the buttock or groin, sometimes radiating down the back of the thigh like sciatica. It is more common in women and can follow a fracture or hip surgery, or arise with no clear event. MRI typically shows a narrowed space and swelling or wasting of the quadratus femoris, and a numbing injection into the space is sometimes used to confirm the source. Treatment is usually physiotherapy, sometimes an injection, and rarely surgery to widen the space.

The neuroplastic contribution

Neuroplastic symptoms are real symptoms produced by learned pathways in the brain and nervous system rather than by ongoing damage in the body. Pain is the brain's protective alarm. After months of hip pain, an alarm can become sensitized and keep firing even when the bones are no longer pinching, or fire far more loudly than the pinch warrants. The pain is genuine. It is not imaginary and not 'all in your head'. Because the brain can learn, it can also unlearn.

The ATNS Index of Neuroplastic Symptoms is specific. Ischiofemoral impingement is not due to neuroplastic symptoms. But an assessment for neuroplastic symptoms should be part of a complete evaluation when:

• the symptoms are not typical: pain that spreads well beyond the buttock, affects both hips, or is present at rest and at night rather than with the provoking movements;
• the course over time is not typical: pain that keeps worsening or spreading although the imaging is stable, or that persists long after a surgery that corrected the space;
• the response to treatment is not as expected: a diagnostic injection that numbs the space but does not change the pain, or physiotherapy and procedures that help far less than they should.

There is also a built-in trap. A narrow ischiofemoral space can be seen on scans of people who have no pain, so finding one does not automatically explain the pain in front of you. The central sensitization model helps make sense of a hip that stays painful when its structure is quiet.

What the research shows

The research on ischiofemoral impingement is mostly about imaging and anatomy, and there is no study of neuroplastic or brain-focused treatment in this specific condition. What the literature does show is how uncertain the link between the scan and the pain can be.

A 2025 retrospective study of 256 hips in patients having joint-preserving hip surgery found quadratus femoris changes consistent with IFI in 9 percent, with a narrower ischiofemoral distance in those hips and a strong female predominance. Importantly, this was a group being evaluated for hip pain of various kinds, which means the IFI finding was often sitting alongside other possible sources. A physiotherapy case report reviewing the condition notes that IFI can be one-sided or two-sided and cites earlier work suggesting that over a third of people with the imaging finding have no symptoms. A review focused on imaging and ultrasound-guided procedures stresses that the diagnosis requires a combination of clinical symptoms and imaging findings, not the scan alone.

The scan, in other words, is necessary but not sufficient. The wider chronic pain literature shows that long-standing hip pain can carry a sensitized nervous system component, but for IFI the evidence of a brain contribution is indirect and thin, and that is said plainly here. The ATNS index's instruction to assess when the course is atypical is a sensible response to that uncertainty.

Signs the brain may be part of the picture

• A diagnostic injection numbed the space but the pain barely changed.
• Pain persists months after surgery or physiotherapy that should have resolved the pinch.
• Pain is present at rest or at night, or spreads to the whole hip, the thigh or both sides.
• The imaging has not changed, but the pain keeps growing.
• Pain flares with stress, poor sleep or worry more than with the provoking movements.

A solution that addresses it

Pain and symptom reprocessing is an approach built for the part of the pain the nervous system is producing. It combines education about neuroplastic pain, somatic tracking (attending to the deep hip sensation with curiosity rather than dread), reducing fear and threat, a graded return to walking and movement, emotional awareness and expression, and acceptance and commitment skills. Trained clinicians deliver it, and digital programs now make it more accessible. It works alongside, not instead of, your orthopaedic and physiotherapy care.

Cindra is a daily AI companion built around these approaches, with daily check-ins, short practices and plain-language lessons for people whose pain has a neuroplastic component. If your hip pain has outlasted the explanation, you can join the waitlist.

What to do next

1. Get the structure assessed properly. Deep hip pain has many causes: labral tears, femoroacetabular impingement, gluteal tendinopathy, sciatic nerve irritation and more. See a clinician who can examine you and interpret the MRI in context.
2. Give targeted treatment a fair go. Physiotherapy for hip control and load, and a diagnostic injection if offered, give you useful information as well as relief.
3. If the picture is atypical, ask. 'Could a sensitized nervous system be part of this?' The ATNS index says this assessment belongs in a complete evaluation when the course or response is not as expected.
4. Start learning and moving. Read hurt is not harm and begin a gentle, graded return to the strides you have been avoiding.

See a doctor promptly for hip pain after a fall or injury, inability to bear weight, fever, or numbness and weakness in the leg.

This article is for general education and is not medical advice, and it does not diagnose or treat any condition. Persistent symptoms deserve a proper medical assessment to rule out disease or injury before a neuroplastic explanation is considered. If your symptoms are new, changing, or come with red-flag signs such as fever, unexplained weight loss, numbness or weakness, chest pain, or loss of bladder or bowel control, see a clinician promptly.