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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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
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.
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 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
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
It measures maximal isometric hip external rotation strength with the hip positioned in neutral, or 0° hip flexion.
Hip muscle contribution and force output can change with joint position. Testing both positions may provide a broader picture of hip rotational strength.
Peak force is the main routine outcome measure.
Yes. Bilateral testing allows side-to-side comparison and improves progress tracking.
No. It measures muscle force only and should be interpreted alongside other assessment findings.
Pelvic rotation can change the force direction and make the result less repeatable.
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.
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.
