Ischiofemoral Impingement: (Hip)

Ischiofemoral impingement (IFI) is a condition that causes deep pain in the buttock or hip, sometimes radiating into the back of the thigh. It happens when the space between the upper thigh bone (femur) and part of the pelvis (ischium) becomes narrowed. This space normally allows a small muscle, called the quadratus femoris, to move freely. When the space is reduced, the muscle and nearby soft tissues can become pinched or irritated.

Symptoms may include aching or sharp pain in the buttock, discomfort with long walking strides, running, or activities that extend the hip backward. Some patients also notice sciatica-like pain, numbness, or tingling in the back of the leg if the nearby sciatic nerve is irritated. Sitting for long periods or twisting the hip outward can also worsen symptoms.

IFI can develop for many reasons. Some people are born with natural differences in hip shape that reduce the available space. Others may develop it after hip surgery, arthritis, or injury. Functional factors such as weak hip muscles, poor pelvic control, or repetitive hip movements in sports like running, ballet, or rowing also play a role. Women are more commonly affected, and both hips may be involved in up to 40% of cases.

Treatment usually starts conservatively, focusing on reducing irritation and improving hip function. Activity changes, stretching, and strengthening exercises are often recommended. With proper care, most people experience relief, improve their mobility, and return to their normal activities.