The Prone Hip External Rotation Test measures how far the hip rotates outward with the client lying face down and the knee bent. It can be tested actively or passively using a goniometer or inclinometer. The result helps compare sides, monitor hip rotation and add context to squatting, gait, running, cutting, hip strength and movement assessments.
A client may feel restricted rotating the hip outward, show asymmetry during squats or have difficulty moving into positions that require hip external rotation. Measuring prone hip external rotation helps quantify the movement and track change over time.
Like internal rotation, prone hip external rotation is sensitive to pelvic movement. If the pelvis lifts or rotates, the result may not reflect true hip rotation.
Test name: Prone Hip External Rotation Test
Purpose: Measure hip external rotation ROM in prone
Movement: Hip rotates outward while the lower leg moves inward
Joint/body region: Hip
Plane: Transverse plane
ROM type: Active ROM, passive ROM or both
Score: Degrees of hip external rotation
Equipment: Goniometer, inclinometer or Measurz ROM workflow
Best used with: Prone hip internal rotation, supine hip rotation, FABER, squat, gait, running and hip strength testing
Key limitation: Pelvic rotation and inconsistent knee angle can affect results
The Prone Hip External Rotation Test measures the hip’s ability to rotate outward while the client lies prone with the knee flexed, commonly to 90 degrees. In this position, the lower leg moves inward as the femur externally rotates.
The test is used to quantify hip external rotation, compare sides and monitor progress.
It may help inform:
Hip mobility programming
Squat and hinge assessment
Gait and running analysis
Change-of-direction assessment
Lower-limb strength programming
Side-to-side comparison
Progress tracking across sessions
The test measures hip external rotation ROM in degrees.
It may be influenced by:
Hip joint movement
Pelvic position
Femoral version
Soft tissue tolerance
Pain or symptoms
Knee flexion angle
Client relaxation
Measurement method
Professional stabilisation
The result does not explain the cause of movement difference on its own.
Active prone hip external rotation measures how far the client can rotate the hip outward using their own control.
Passive prone hip external rotation measures available motion when the professional guides the leg.
Active and passive values should be labelled separately because they may differ due to control, strength, symptoms or available motion.
This test may be useful for runners, field sport athletes, dancers, lifters, gym clients and anyone where hip rotation affects movement, training or side-to-side comparison.
Treatment table or mat
Goniometer or inclinometer
Pain scale
Measurz for recording ROM
Optional towel under pelvis or thigh
Optional comparison side notes
Position the client prone.
Flex the tested knee to approximately 90 degrees. Keep the pelvis level and the thigh aligned with the body.
Stand beside or at the foot of the tested limb with a clear view of pelvic movement.
Start with the lower leg vertical or in the agreed neutral position.
Stabilise the pelvis to reduce pelvic lift or rotation.
For active ROM, ask the client to move the foot inward while keeping the thigh down and pelvis still.
For passive ROM, gently move the lower leg inward to externally rotate the hip until the first firm endpoint, symptom limit or compensation threshold.
For goniometry, the axis is commonly centred over the anterior knee or patella, with the stationary arm vertical and moving arm along the tibia.
If using an inclinometer, place it consistently on the tibia or lower leg. Record placement.
Ask about anterior hip symptoms, posterior hip stretch, groin symptoms, stiffness, symptom location and whether symptoms are familiar.
Stop if pelvic movement dominates, pain increases, symptoms are not tolerated or the client guards.
Record active/passive method, side, degrees, pain score, symptom location, knee angle, device used and compensation.
One to three trials may be used. Record best, average or selected trial consistently.
Use the same knee angle, position, device, pelvis control and endpoint each session.
The score is recorded in degrees.
A higher value means more hip external rotation under the tested setup. A lower value means less external rotation compared with the other side, baseline or selected reference value.
Interpretation is stronger when paired with:
Pain score
Symptom location
Active versus passive comparison
Prone hip internal rotation
Supine hip rotation
FABER or hip quadrant findings
Squat, gait or running assessment
Hip strength findings
The result does not explain why rotation differs. Anatomy, symptoms, control and measurement method can all influence hip rotation.
Evidence level: Level 2–3 — common reference values exist, but hip rotation varies widely.
Common teaching references often describe hip external rotation around 40–45 degrees, but values vary by position, age, sport, femoral version, symptoms and measurement method.
Practical benchmarks:
Compare both sides
Track baseline to retest
Compare internal and external rotation
Record pain and symptoms
Record pelvic compensation
Use the same prone setup each session
A 2023 study assessing active hip ROM with inertial measurement units included prone hip internal and external rotation and compared digital methods with goniometer and inclinometer approaches, supporting the need for consistent measurement method and device placement.
A 2020 hip ROM reliability study found excellent reliability for selected hip measures, including external rotation, among experienced examiners, while also showing that pelvic position can significantly influence hip ROM values.
Common errors include pelvic lift, inconsistent knee angle, not stabilising the pelvis, forcing passive end range, unclear active/passive labelling, not recording symptoms and comparing prone and supine rotation values as if identical.
Limitations include femoral version influence, pelvic compensation, symptoms, measurement error, body position differences and device variation.
Use prone hip external rotation ROM to monitor hip rotation, compare sides and add context to squat, running, cutting, gait and lower-limb strength assessments.
In Measurz, record baseline prone hip external rotation ROM in degrees using the inclinometer or chosen device. Note active or passive method, side tested, pain score, symptom location, knee angle, test position, device used and pelvic compensation.
Compare both sides and track progress across sessions. Add related hip internal rotation, hip strength, squat, running, gait or functional findings and retest date.
Prone Hip Internal Rotation Test
Supine Hip Internal Rotation Test
Supine Hip External Rotation Test
FABER Test
Hip Flexion Test
Hip Extension Test
Squat Assessment
Running Assessment
Common references often describe around 40–45 degrees, but values vary by position, age, sport, anatomy, symptoms and measurement method.
Position the client prone, flex the knee to about 90 degrees, move the lower leg inward and measure the hip rotation angle.
Both can be useful, but active and passive results should be recorded separately.
Pelvic rotation can make hip external rotation appear greater than it really is.
Use the same prone position, knee angle, device, pelvis control and endpoint each session.
Prone hip external rotation measures outward hip rotation.
The lower leg moves inward during the movement.
Pelvic control and knee angle must be standardised.
Active and passive values should be recorded separately.
Measurz should capture degrees, side, pain, method, knee angle and compensation.
Charlton, P. C., et al. (2020). Reliability of hip range of motion measurement among experienced hip preservation surgeons. Journal of Hip Preservation Surgery, 7(1), 77–84.
Clarkson, H. M. (2020). Musculoskeletal assessment: Joint range of motion, muscle testing, and function (4th ed.). Wolters Kluwer.
Słomka, K. J., et al. (2023). Validity and reliability of inertial measurement units in active range of motion tests. Sensors, 23(21), 8782.
