FABER Test for hip mobility (Patrick's test, mobility approach)

The FABER test (Flexion-ABduction-External Rotation), also known as Patrick's test, is one of those classic tests that show up in pretty much every hip assessment. Here we're going to look at it from a mobility/flexibility angle: how much range the person has, not whether pain is reproduced from a possible sacroiliac or hip pathology.

If you work with people who feel like their hips are "tight" or who complain when sitting cross-legged, this test gives you very direct information.

What does this test measure?

It assesses passive flexibility of the hip adductors, the hip external rotators (especially the piriformis), and sacroiliac joint mobility, all in a single position: the classic "figure 4" formed by placing the ankle on top of the opposite knee while lying down.

Important: don't confuse this with the 90/90 test. The FABER is a passive flexibility measurement taken lying down (supine). The 90/90 test is an active measurement of internal/external rotation range taken in sitting, with a motor control component. These are different tests and aren't interchangeable: the FABER tells you how much range is "available" passively, while the 90/90 tells you how much range can actually be "used" actively.

Equipment needed

• A table or flat surface
• A tape measure or goniometer/inclinometer

Test protocol

1. The person lies supine (face up) on the table
2. Ask them to place the ankle of the side being tested on top of the opposite knee, forming a "4" shape with the legs (hip in flexion, abduction, and external rotation)
3. Let the knee of the tested side drop toward the table under gravity, without forcing or pushing it
4. Measure the distance between the knee and the table (in cm), or the angle of the femur relative to horizontal using an inclinometer
5. Also check whether the pelvis rises or rotates during the movement (compensation)
6. Repeat on the opposite side and compare

Common mistakes

• Actively pushing the knee down (it should drop under gravity, not be forced)
• Not stabilizing the opposite side of the pelvis, allowing it to rotate and skew the result
• Confusing this test with the 90/90 because of the similar "hip at 90 degrees" name
• Not testing the opposite side for comparison

How to interpret the result

Knee-to-table distance / angle	Interpretation
Knee close to the table (< 5 cm) or angle close to 0° from horizontal	Good adductor and external rotator flexibility
5-10 cm of distance, or 10-20° from horizontal	Mild-to-moderate restriction, common in sedentary people
> 10 cm, or > 20-25°	Marked restriction of adductors/external rotators or sacroiliac limitation
Noticeable asymmetry between sides	A possible imbalance worth addressing specifically, especially in running sports or sports involving changes of direction

Unlike an orthopedic pain test (where the goal is to reproduce symptoms in the groin or sacroiliac area), here the focus is on available range, compared between sides.

How it relates to other tests

The FABER pairs especially well with:

• 90/90 hip test — assesses active rotation range, while the FABER assesses passive flexibility; together they give a complete picture of the hip
• Thomas test — if the hip is "tight" on the FABER, it's also worth checking hip flexor flexibility

Track it and follow up

Adductor and external rotator flexibility has a major impact on running mechanics, deep squat depth, and open-hip positions (yoga, martial arts, dance). With Movalytics you can log the distance or angle for each side on the FABER test, track changes after a block of mobility work, and spot asymmetries that could be linked to asymmetric overload.

Frequently asked questions

Does a positive FABER test always mean a sacroiliac problem? Not necessarily. From a mobility perspective, a restricted FABER usually just reflects limited adductor and external rotator flexibility. Pain assessment of the sacroiliac joint is a different (more diagnostic) clinical use of the same test. What's the real difference between the FABER and the 90/90? The FABER is performed lying down and measures passive flexibility (the knee drops under gravity). The 90/90 is performed seated and measures active rotation range with a motor control component. Both assess "hip mobility," but in different contexts and directions, which is why they're often used together. Can stretching improve FABER results? Yes, it usually responds well to adductor and piriformis stretching, along with hip joint mobility work through large ranges of motion.