Anterior iliopsoas impingement

Anterior iliopsoas impingement refers to mechanical irritation of the iliopsoas tendon as it passes over the front of the hip joint. It can cause anterior or groin pain, sometimes associated with snapping hip, particularly when moving from flexion to extension.

In reality, the term covers several related but distinct situations: iliopsoas tendinopathy or tendinobursopathy, mechanical impingement between the tendon and the anterior structures of the hip, internal snapping hip (or coxa saltans interna), irritation of the iliopsoas bursa, impingement associated with a morphological abnormality of the hip, or irritation secondary to hip surgery or a hip replacement.

In runners, the condition is most often linked to repetitive overload of the hip flexor, but a mechanical abnormality can perpetuate the symptoms. It is therefore important to look for a possible associated condition: femoroacetabular impingement, labral tear, dysplasia, adductor tendinopathy or a pubic condition.

These different mechanisms (tendinopathy of the tendon, bursopathy of the surrounding bursa, mechanical impingement during certain hip movements, and internal snapping when the tendon moves perceptibly) are often used interchangeably in everyday language, but they do not describe exactly the same thing. They can also coexist in the same patient.

The iliopsoas is the main flexor of the hip. It is made up of two muscles, the psoas major and the iliacus, which join together towards the lesser trochanter of the femur. The common tendon passes in front of the hip joint before inserting there.

An iliopsoas bursa lies between the tendon and the deep structures of the hip. This bursa can become inflamed and itself contribute to the pain, independently of or in association with tendon involvement.

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Role of the iliopsoas in runners

The iliopsoas is mainly involved in hip flexion, stabilisation of the femoral head, pelvic control, rapid thigh movements and bringing the lower limb forward.

In runners, it contributes in particular to bringing the thigh forward during the swing phase of the stride, preparing for foot contact, pelvic control, running uphill and accelerations. It therefore works thousands of times in every session, which explains its vulnerability to repetitive overload.

Anterior iliopsoas impingement is a common cause of groin or anterior hip pain in runners, often linked to repetitive overload of the hip flexor during the repeated flexion, extension and accelerations of running.

Internal snapping hip, a frequently associated component, is a common and often benign finding: isolated, painless snapping does not necessarily indicate a disorder and does not systematically require treatment. The problem becomes truly pathological when the snapping is painful, repetitive, associated with functional limitation or responsible for reduced performance.

Persistent groin pain in a runner should also always prompt a search for a possible associated intra-articular condition (femoroacetabular impingement, labral tear, dysplasia), which can alter the muscle strategy around the hip and perpetuate the symptoms.

The iliopsoas tendon can be heavily loaded when the hip repeatedly performs flexion and extension movements, rapid movements, changes in range of motion and accelerations.

Situations that increase loading

Certain training situations particularly increase the load on the tendon: a sudden increase in mileage, interval training, hills, trail running, speed work, returning after a break, a change in running technique, or a substantial increase in elevation gain. Muscle fatigue can also alter the hip stabilisation strategy and promote irritation of the tendon.

Contributing factors

In terms of training, the same situations as above are found: a sudden increase in volume, too rapid a return, interval training, hills, trail running, repeated accelerations, long sessions and insufficient recovery.

In terms of muscles, a strength deficit of the gluteus medius, weakness of the gluteus maximus, a trunk deficit or overall weakness of the lower limb can contribute to overload of the hip flexor.

In terms of mobility, limited hip mobility, a thoracic mobility deficit or poor ankle mobility can also play a role. However, a single isolated deficit should not be regarded as the necessary cause of the impingement: these factors usually combine rather than act alone.

Influence of hip morphology

Certain hip morphologies can alter the stresses placed on the iliopsoas: femoroacetabular impingement, cam morphology, pincer morphology, dysplasia or abnormalities of the acetabular rim. An intra-articular injury can also cause a change in the muscle strategy around the hip. In a patient with persistent groin pain, a possible associated intra-articular condition should therefore always be looked for.

Groin and anterior pain

The classic presentation is deep anterior pain located in the groin; the patient can sometimes point to the painful area with one finger. The pain may appear when climbing stairs, getting into a car, running, accelerating or running uphill.

Some patients feel pain when moving from sitting to standing, or when moving from a flexed hip to an extended hip. An anterior clunk may also be felt during the movement, sometimes loud enough to be audible.

Running-related pain

In runners, the pain may appear at the start of a run, after several kilometres, during accelerations, on hills, with a long stride or after a demanding session. Some runners feel little pain during training but have pain after the session, when walking, climbing stairs or moving from sitting to standing.

Internal snapping hip

Internal snapping refers to movement of the iliopsoas tendon during certain hip movements. It can be audible, palpable, visible, painful or completely painless. It classically occurs when moving between flexion and extension, sometimes with a deep clunking sensation in the groin.

Isolated, painless snapping is often a benign finding and does not necessarily require treatment. The problem becomes pathological when the snapping is painful, repetitive, associated with functional limitation, or responsible for reduced performance.

Clinical examination

The examination assesses the precise location of the pain, hip mobility, pain on resisted flexion, pain on stretching the iliopsoas, snapping, muscle strength, pelvic stability and any intra-articular pain. Palpation of the iliopsoas region may reproduce the pain: the Doha agreement considers that the combination of pain on palpation of the iliopsoas with pain on resisted flexion and/or on stretching of the flexors makes iliopsoas-related pain more likely.

The resisted flexion test involves performing hip flexion against resistance; it is considered positive when it reproduces the patient’s usual pain, and not simply muscular discomfort, since a strong contraction of a poorly trained muscle can be uncomfortable without indicating a disorder.

The iliopsoas stretch test gradually takes the hip into extension, possibly with the knee flexed; reproduction of the usual pain may point towards iliopsoas involvement. However, no single test can confirm the diagnosis with certainty: a systematic review published in 2026 highlights that the available clinical tests remain imperfectly validated and that current diagnostic data are still limited.

Testing for snapping involves looking for a reproducible hip movement that triggers the clunk, often provoked by a combination of flexion, abduction and external rotation, followed by a return towards extension and internal rotation. Dynamic ultrasound can directly visualise the movement of the tendon and is a particularly useful examination when the snapping is difficult to demonstrate clinically.

Surgery is rarely necessary. It may be considered in selected situations: persistent painful internal snapping, failure of properly conducted conservative management, clearly identified mechanical impingement, or an associated intra-articular condition requiring arthroscopy.

The procedure may involve lengthening or partial release of the iliopsoas tendon, but this procedure should be considered with caution: excessive release can lead to weakness in hip flexion, psoas atrophy, altered stability and functional deficit. A recent systematic review also highlights the current uncertainty about the specific benefit of iliopsoas release in native hips, and reports a risk of reduced flexion strength and muscle atrophy.

In some patients, the problem is not just the tendon: cam impingement, pincer impingement, a labral tear or cartilage damage may coexist. In these situations, arthroscopy can treat the intra-articular lesions and the associated mechanical impingement at the same time, with the decision depending on a full assessment of the hip. The general principle of the guidelines on femoroacetabular impingement is that surgery should only be considered when symptoms, clinical examination and imaging are consistent with one another.

After surgery, recovery depends on the procedure performed (iliopsoas lengthening, labral repair, cam/pincer correction) and on the recovery of strength. Rehabilitation is progressive: recovery of mobility, muscle activation, strengthening, single-leg work, impacts, running, speed and then sport-specific work. Return to running generally takes place after several weeks to several months depending on the procedure performed; there is no universal timeframe.

Before resuming regular running, the ideal is to have minimal pain in daily life, functional mobility, no significant painful snapping, sufficient hip strength, good trunk strength, good single-leg stability, good tolerance of jumping, and no significant symptomatic reaction the next day. Progression is then guided by tolerance rather than by a fixed schedule.

It is not possible to prevent all iliopsoas problems, but certain strategies can reduce episodes of overload.

In terms of load progression, sudden increases in mileage, speed, hills and interval training should be avoided. In terms of strengthening, it is useful to maintain the strength of the glutes, quadriceps, hamstrings, iliopsoas and trunk muscles.

Single-leg work helps maintain good pelvic control, and sufficient recovery between intense sessions helps avoid the accumulation of load without adaptation.