A positive FABER test generally indicates a problem in the hip joint, the sacroiliac (SI) joint, or both. The name stands for Flexion, Abduction, and External Rotation, describing the position your leg is placed in during the exam. Where exactly you feel pain during the maneuver, and how restricted your movement is, gives your clinician clues about which structure is involved. But because the test stresses several anatomical areas at once, a positive result on its own rarely points to a single diagnosis.
How the Test Works and Why Pain Location Matters
During a FABER test, you lie on your back while the examiner places the ankle of the tested leg on top of the opposite knee, forming a figure-four shape. The examiner then gently presses the bent knee toward the table. This combined movement of flexion, abduction, and external rotation loads the hip joint, stretches the muscles around it, and applies a shearing force across the SI joint at the back of the pelvis. Beyond being used as a pain provocation test, clinicians sometimes measure how far the knee drops toward the table as an indicator of overall hip range of motion, with limited motion suggesting possible hip pathology.
1PubMed Central. THE RELIABILITY OF FABER TEST HIP RANGE OF MOTION MEASUREMENTSThe location of the pain you report is the first interpretive fork. Groin pain or pain at the front of the hip during the test points toward an intra-articular hip problem, meaning something inside the hip joint itself. Pain felt at the back of the pelvis or deep in the buttock region points toward the SI joint. Some people feel pain in both places, which is one reason the test can be tricky to interpret. Because the FABER position simultaneously stresses the hip capsule, the surrounding muscles, and the SI joint, it can provoke pain from the lower lumbar spine’s facet joints as well, adding another layer of ambiguity.
2Journal of Orthopaedics Trauma Surgery and Related Research. Reliability of FABER test in correlation with alpha angle in diagnosis of cam type femoroacetabular impingementHip Joint Conditions the FABER Test Can Flag
When a positive FABER test produces pain in the groin or front of the hip, several intra-articular conditions are on the table. The most commonly discussed are labral tears, femoroacetabular impingement (FAI), and hip osteoarthritis.
Labral Tears
The labrum is a ring of cartilage lining the rim of the hip socket. Tears in this structure are a frequent cause of hip pain, especially in younger and active people. One systematic review looking at physical examination tests for prearthritic hip pathology found that the FABER test had the highest specificity for diagnosing labral tears when compared against either MRI findings or direct visualization during hip arthroscopy.
3Arthroscopy, Sports Medicine, and Rehabilitation. Hip Sensitivity and Specificity for Physical Examination Tests in Diagnosing Prearthritic Intra-Articular Hip Pathology Are Highly Variable: A Systematic ReviewThat sounds impressive, but context matters. The same review noted that the sensitivity and specificity figures for hip physical exams in general are highly variable across studies. Clinicians often use the FABER test alongside the FADIR test (flexion, adduction, internal rotation), which tends to be more sensitive for labral tears. The FABER test’s strength is more about ruling in a labral problem when it is positive, while FADIR is better at ruling one out when negative.
Femoroacetabular Impingement
FAI occurs when extra bone growth on the femoral head (called a cam deformity) or the rim of the socket (a pincer deformity) causes the bones to grind against each other during movement. The FABER test is considered sensitive for the cam type of FAI, meaning that most people who have it will test positive. One prospective study found that the FABER test had a significant positive predictive value for cam-type FAI, though it cautioned that a negative test cannot completely rule out the diagnosis because the test’s specificity is relatively low.
4Semantic Scholar. Reliability of FABER test in correlation with alpha angle in diagnosis of cam type femoroacetabular impingementHip Osteoarthritis and Other Intra-Articular Problems
For detecting intra-articular hip pathology more broadly, including osteoarthritis, the FABER test performs reasonably well as a screening tool. A study evaluating hip provocation maneuvers against a reference standard of intra-articular injection found that the FABER test had a sensitivity of about 82%, meaning it caught most cases, but a positive predictive value of only around 46%.
5PubMed Central. The diagnostic validity of hip provocation maneuvers to detect intra-articular hip pathologyIn practical terms, that means a positive FABER test is decent at raising suspicion for a hip joint problem, but fewer than half of positive results will turn out to reflect confirmed intra-articular pathology. This is partly because the test is nonspecific, stressing multiple structures at once. It’s a useful signal, not a definitive one.
Sacroiliac Joint Inflammation
When a positive FABER test produces pain in the back of the pelvis rather than the groin, the SI joint becomes the primary suspect. The SI joint connects the base of the spine to the pelvis, and inflammation there (sacroiliitis) is a hallmark of conditions like ankylosing spondylitis and other forms of spondyloarthritis. Because these conditions are notoriously slow to diagnose, the FABER test plays a practical role in clinical screening.
A study of patients with low back pain found that a positive FABER test had a sensitivity of about 76% and a specificity of about 66% for detecting sacroiliitis confirmed by MRI. Patients with a positive test were roughly six times more likely to have sacroiliitis on MRI compared to those who tested negative.
6PubMed. Role of Patrick-FABER test in detecting sacroiliitis and diagnosing spondyloarthritis in subjects with low back painAnother study in patients with inflammatory back pain found the FABER test to be the most sensitive clinical test for sacroiliitis at 75%, though its specificity was low at around 19%.
7PubMed Central. The Diagnostic Value of Clinical Sacroiliac Joint Pain Provocation Tests for Detection of Sacroiliitis Identified by MRI in Sampled Iraqi Patients with Inflammatory Back PainThe gap between those two specificity numbers (66% vs. 19%) is worth noting. It reflects real variability in how different study populations, different examiners, and different reference standards can shift the test’s performance. A single study’s numbers should never be taken as the definitive accuracy of this test.
Why Clinicians Rarely Rely on One Test Alone
The FABER test stresses the hip joint, the SI joint, the surrounding muscles, and even the lower lumbar facet joints all at once. That is its limitation in a nutshell. A positive result gets the conversation started, but it does not end it. This is why experienced clinicians use it as part of a cluster of tests rather than in isolation.
For the SI joint specifically, combining the FABER test with other provocation maneuvers improves diagnostic accuracy. A systematic review with meta-analysis of studies using clusters of SI joint provocation tests found that when multiple tests are positive, the likelihood of SI joint pain being the true source increases meaningfully. But even with clustering, the certainty of the evidence was rated very low.
8PubMed. Diagnostic Accuracy of Clusters of Pain Provocation Tests for Detecting Sacroiliac Joint Pain: Systematic Review With Meta-analysisOne particularly useful pairing is the FABER test with the thigh thrust test. A study comparing SI joint diagnostic tests found that the FABER test had the highest specificity and positive predictive value among the physical tests examined, and combining it with the thigh thrust test improved overall diagnostic ability more than any other combination.
9PubMed Central. Accuracy of the Diagnostic Tests of Sacroiliac Joint DysfunctionFor hip joint problems, the typical approach is similar. A clinician might pair the FABER test with the FADIR test, passive range-of-motion assessments, and a thorough history. If the pattern points toward intra-articular pathology, imaging (usually an MRI or an MRI with contrast injected into the joint) often follows.
The FABER Distance Test
Beyond the simple question of whether the FABER position hurts, some clinicians measure the actual distance between the tested knee and the exam table. This quantitative version, called the FABER distance test (FDT), adds a layer of information. A larger distance, meaning the knee stays high and doesn’t drop toward the table, suggests more restricted hip motion and potentially more significant pathology.
A study of symptomatic patients found that those with a positive FABER distance test had higher alpha angles on imaging, which is a measure of the cam deformity associated with FAI. The average alpha angle in patients with a positive distance test was 74 degrees compared to 68 degrees in those with a negative distance test. The sensitivity of the FABER distance test for diagnosing a pathological cam deformity was about 85%, with a negative predictive value of 86%.
10PubMed. Positive FABER distance test is associated with higher alpha angle in symptomatic patientsThat high negative predictive value is clinically useful. If your knee drops close to the table and the distance test is negative, there’s a strong chance you don’t have a significant cam deformity. The distance version of the test essentially converts a subjective “does it hurt” question into something more measurable, which can be valuable for tracking changes over time or across visits.
How Reproducible Is the Test Between Examiners?
Any clinical test is only as useful as its consistency. If two different clinicians perform the FABER test on the same patient and reach different conclusions, that’s a problem. The evidence on the FABER test’s inter-rater reliability is moderate. One study found a kappa coefficient of 0.63 for the FABER test when two examiners independently assessed the same patients, placing it in the range of “substantial” agreement by conventional standards.
11PubMed. The interrater reliability of 4 clinical tests used to assess individuals with musculoskeletal hip painWhen the FABER test is used to measure range of motion (rather than just provoke pain), the picture is similar. Inter-rater reliability was good, and within the same examiner across different sessions, reliability was good to excellent. Using an inclinometer rather than a ruler improved consistency further.
1PubMed Central. THE RELIABILITY OF FABER TEST HIP RANGE OF MOTION MEASUREMENTSOne weakness stood out, though: when clinicians tried to assess the symmetry between the two hips (comparing the FABER distance on the left side versus the right), reliability dropped substantially. The same study reported poor inter-rater reliability for side-to-side symmetry measurements. So while individual-side measurements are reasonably consistent, comparing the two hips against each other is where examiners diverge the most.
1PubMed Central. THE RELIABILITY OF FABER TEST HIP RANGE OF MOTION MEASUREMENTSTracking Recovery After Hip Surgery
The FABER test isn’t only used for initial diagnosis. It also serves as a monitoring tool after treatment, particularly following hip arthroscopy for FAI. A five-year follow-up study of patients who had hip arthroscopic surgery found that the proportion of patients with a positive FABER test dropped significantly from preoperative levels, with about 25% still testing positive five years after surgery.
12PubMed Central. Five-Year Follow-up After Hip Arthroscopic Surgery in the Horsens-Aarhus Femoroacetabular Impingement (HAFAI) CohortThat one-in-four figure is notable. It means a meaningful minority of people continue to have a positive FABER test years after surgery, which may reflect residual pathology, incomplete recovery, or the development of secondary changes in the joint. In that same study, patients who still had a positive FADIR test (the companion hip test) at five years reported substantially worse functional outcomes. While the study focused on FADIR for functional outcomes, the persistence of positive physical exam findings after surgery underscores why these tests remain relevant well beyond the initial diagnostic workup.
Common Reasons for Confusion
One common misunderstanding is assuming a positive FABER test means you definitely have a hip problem. As outlined above, the test provokes pain from multiple sources, and a positive result might reflect SI joint dysfunction, a lumbar facet issue, or tight hip musculature rather than anything wrong inside the hip joint itself. The pain location during the test is the first clue, but even that isn’t always clear-cut. Some patients struggle to localize the pain precisely, and overlapping anatomy can muddy the picture.
Another point of confusion arises with side-to-side comparisons. Many people expect the test to be performed on both sides so the clinician can compare. While that comparison can provide useful context, the reliability data for symmetry assessments are weaker than for individual-side measurements. A difference between your left and right sides could reflect genuine pathology, normal anatomical variation, or examiner technique. It is most useful when the asymmetry is large and consistent with your symptoms.
Finally, the FABER test is sometimes called the Patrick test. The two names refer to the same maneuver. “FABER” is the acronym describing the leg position, and “Patrick” is the name of the physician traditionally credited with popularizing it. If you see either term in a clinical note, they mean the same thing, which is confirmed by studies that use the terms interchangeably.
6PubMed. Role of Patrick-FABER test in detecting sacroiliitis and diagnosing spondyloarthritis in subjects with low back painWhen Imaging Follows a Positive FABER Test
A positive FABER test alone almost never leads directly to surgery or a definitive diagnosis. What it typically triggers is further investigation. If groin pain suggests a hip joint problem, the next step is usually imaging. A standard X-ray can reveal osteoarthritis or bony abnormalities like cam or pincer deformities. An MRI, sometimes enhanced with contrast injected directly into the joint (called an MR arthrogram), is the go-to for suspected labral tears. If the pain pattern points toward the SI joint, an MRI of the pelvis focusing on the sacroiliac joints is the standard follow-up, particularly when spondyloarthritis is suspected.
In some clinical pathways, a diagnostic injection is used as the reference standard. For the hip, an anesthetic injected directly into the joint under imaging guidance can confirm that the hip is the pain source. For the SI joint, a similar guided injection serves the same purpose. These injections essentially answer the question: is this joint actually what’s hurting? A positive FABER test is one of the clinical signals that helps a provider decide whether that injection is warranted.
The test’s role, then, is as a screening and triaging tool. It helps clinicians narrow the field, decide which imaging to order, and build a clinical picture that combines your symptoms, your history, and the results of several physical exam maneuvers. A positive FABER test is a piece of a puzzle, and knowing where you felt the pain during the test is often the most diagnostically valuable piece of information it provides.