The Hip External Rotation Strength Test measures the maximum isometric force produced during hip external rotation with the hip positioned in neutral, or 0 degrees of hip flexion. Using the Anker, the assessment provides an objective measure of hip external rotator strength in a fixed and repeatable position.

Testing hip external rotation at 0° complements testing at 90° of hip flexion because hip muscle contribution can change with joint position. This makes the assessment useful for baseline strength profiling, side-to-side comparison and monitoring changes over time.

The primary muscles contributing to hip external rotation include gluteus maximus, piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus and quadratus femoris. These muscles contribute to hip stability, lower-limb alignment, gait, running, cutting, jumping and landing control.

When used with Measurz, the Anker records peak force and can calculate additional force-time metrics including force relative to body weight, impulse, torque when the lever arm is entered, rate of force development, time to peak and fatigue index.

The assessment measures muscle strength only and should always be interpreted alongside symptoms, movement quality and functional performance.

What Is the Hip External Rotation Strength Test?

The Hip External Rotation Strength Test is an isometric assessment performed with the hip in a neutral position. The client attempts to rotate the leg outward by pushing the lower leg against the Anker while keeping the pelvis, trunk and testing limb stable.

Unlike hip external rotation testing at 90° hip flexion, testing at 0° assesses force production with the hip closer to a standing or extended-limb position. This may provide useful context for gait, running, standing control and lower-limb alignment tasks.

The Anker’s fixed resistance and independent load cells allow the assessment to be reproduced consistently when the same position, contact point and instructions are used each time.

Step-by-Step Protocol

1. Prepare the client

Explain that the assessment measures how strongly they can rotate their leg outward without allowing the hip, pelvis or trunk to move.

Record any:

• hip pain
• groin pain
• buttock pain
• lower back pain
• recent injury
• previous surgery
• stiffness
• neurological symptoms
• fatigue

Complete one or two submaximal practice contractions before maximal testing.

2. Position the client

Position the client in long sitting or supine, depending on the Anker configuration.

Maintain:

• hips in neutral, or 0° hip flexion
• knees extended unless the protocol specifies otherwise
• pelvis level
• trunk supported
• lower limbs aligned with the pelvis
• feet pointing towards the ceiling

Use the same client position during every reassessment.

3. Position the testing limb

Position the testing limb so that:

• the patella faces directly upwards
• the femur begins in neutral rotation
• the tibia remains aligned with the femur
• the ankle remains relaxed

Position the Anker load cell against the medial aspect of the distal tibia, approximately 2–3 cm superior to the medial malleolus.

Avoid contact directly over the medial malleolus, ankle joint or foot.

Record the contact point so the same setup can be repeated during future testing.

4. Stabilise the client

Prevent movement of:

• pelvis
• lumbar spine
• trunk
• opposite limb
• testing leg

The force should be produced by hip external rotation only, not by rolling the pelvis, lifting the leg or shifting the trunk.

5. Testing instructions

Use consistent verbal instructions.

"Push your leg inwards."

"Build the pressure gradually."

"Push as hard as you can."

"Hold."

"Keep breathing."

Use the same wording during every reassessment.

6. Record the assessment

Use:

• 1–2 familiarisation trials
• 2–3 maximal trials
• 3–5 second contraction
• 30–60 seconds rest between trials

Record either:

• highest value, or
• average of recorded trials

Use the same scoring method during every reassessment.

7. Repeat the trial if

• the pelvis rotates
• the lumbar spine moves
• the testing leg lifts
• the opposite limb assists
• the knee bends unintentionally
• the load cell slips
• pain limits maximal effort
• the client starts before instructed

Why It Is Used

The Hip External Rotation Strength Test may be useful for:

• establishing baseline hip strength
• comparing left and right limbs
• monitoring changes over time
• lower-limb strength profiling
• athlete performance assessment
• monitoring response to exercise
• objective reporting using Measurz
• educating clients about measurable change

The assessment should support broader assessment reasoning and should not be used as a stand-alone diagnostic or clearance measure.

What It Measures

The primary outcome is peak isometric hip external rotation force with the hip positioned in neutral.

When analysed in Measurz, additional metrics may include:

• Peak force
• Force relative to body weight
• Impulse
• Torque
• Rate of force development
• Time to peak
• Fatigue index

The assessment does not directly measure:

• hip range of motion
• joint structure
• movement quality
• balance
• gait mechanics
• running performance
• readiness for sport or work

Understanding the Result, Reference Values and What to Look For

Higher force values generally indicate greater hip external rotation strength in the tested position.

Lower force values may reflect:

• pain
• reduced confidence
• fatigue
• previous injury
• poor familiarisation
• inconsistent positioning
• movement compensation

Interpret results by:

• comparing with the client’s previous assessments
• comparing left and right limbs
• considering symptoms during and after testing
• reviewing compensatory movement
• relating findings to sport, work or daily-life demands

Published Anker-specific normative values are currently unavailable.

Dynamometry research supports the use of standardised hip strength testing for objective force measurement, although values vary depending on device type, body position, lever arm, stabilisation and scoring method. Because of this, published values should be treated as comparison data rather than direct targets for the Anker.

For practical use, the most meaningful comparisons are usually the client’s own baseline, side-to-side differences and change over time. A side-to-side difference around 10% or more may be worth reviewing more closely, particularly when it matches symptoms, previous injury, confidence changes or functional differences.

Assessing Different Client Populations

Youth

Use additional familiarisation trials and interpret results relative to growth, maturation, coordination and activity level.

Adults

Useful for baseline strength assessment, side-to-side comparison and monitoring changes over time.

Older adults

Interpret alongside mobility, balance, transfers, walking confidence and daily function.

Athletes

Useful as part of a broader lower-limb strength profile for running, jumping, cutting, landing and rotational control.

Clients with persistent symptoms

Interpret results alongside pain, confidence, movement quality and functional capacity rather than strength alone.

Common Errors and Limitations

Common errors include:

• pelvis rotating
• lumbar extension
• trunk leaning
• testing leg lifting
• opposite leg assisting
• inconsistent load cell placement
• inconsistent starting position
• inconsistent cueing
• pressing through the foot instead of rotating from the hip

Limitations include:

• results are specific to the testing position
• pain may reduce maximal force production
• strength alone does not determine function
• published Anker-specific normative data remain limited
• testing at 0° and 90° should not be compared directly unless the same protocol and interpretation framework are used

Practical Applications

The assessment may be useful for:

• establishing baseline hip external rotation strength
• monitoring progress over time
• comparing left and right limbs
• lower-limb strength profiling
• athlete performance monitoring
• objective reporting in Measurz
• educating clients using measurable outcomes

FAQs

What does the Hip External Rotation Strength Test measure?

It measures maximal isometric hip external rotation strength with the hip positioned in neutral, or 0° hip flexion.

Why test hip external rotation at both 0° and 90°?

Hip muscle contribution and force output can change with joint position. Testing both positions may provide a broader picture of hip rotational strength.

Which metric should be used routinely?

Peak force is the main routine outcome measure.

Should both hips be tested?

Yes. Bilateral testing allows side-to-side comparison and improves progress tracking.

Can this test diagnose hip pathology?

No. It measures muscle force only and should be interpreted alongside other assessment findings.

Why is pelvis control important?

Pelvic rotation can change the force direction and make the result less repeatable.

Key Takeaways

• Measures maximal isometric hip external rotation strength with the hip in neutral.
• Complements hip external rotation testing at 90° hip flexion.
• Peak force is the primary outcome measure.
• Measurz can provide additional force-time metrics.
• Consistent positioning, contact point and cueing improve repeatability.
• Baseline comparison, side-to-side comparison and retesting consistency are more useful than broad population norms.

References

Bohannon, R. W. (1997). Reference values for extremity muscle strength obtained by hand-held dynamometry from adults aged 20 to 79 years. Archives of Physical Medicine and Rehabilitation, 78(1), 26–32.

Mentiplay, B. F., Perraton, L. G., Bower, K. J., Adair, B., Pua, Y. H., Williams, G. P., McGaw, R., & Clark, R. A. (2015). Assessment of lower limb muscle strength and power using hand-held and fixed dynamometry: A reliability and validity study. PLOS ONE, 10(10), e0140822.

Thorborg, K., Bandholm, T., Schick, M., Jensen, J., & Hölmich, P. (2013). Hip strength assessment using handheld dynamometry is reliable in athletes. Scandinavian Journal of Medicine & Science in Sports, 23(3), e181–e189.