The Hip External Rotation Strength Test measures the maximum isometric force produced during hip external rotation with the hip flexed to 90 degrees. Using the Anker, the assessment provides an objective measure of hip external rotator strength in a fixed and repeatable testing position.
The assessment is commonly used for baseline strength testing, side-to-side comparison and monitoring changes over time. Hip external rotator strength contributes to lower-limb stability during walking, running, jumping, landing and change-of-direction activities.
When used with Measurz, the Anker records peak force and can calculate additional 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 be interpreted alongside other physical assessments and functional performance.
The Hip External Rotation Strength Test is an isometric assessment where the client attempts to rotate the hip outward while the hip and knee remain flexed to 90 degrees.
Primary muscles assessed include:
Gluteus maximus
Piriformis
Obturator internus
Obturator externus
Superior gemellus
Inferior gemellus
Quadratus femoris
The fixed design of the Anker allows consistent testing when the same positioning, contact points and instructions are used during every assessment.
Explain that the assessment measures how strongly they can rotate their hip outward by pushing their lower leg against the Anker.
Record any:
hip pain
groin pain
buttock pain
recent injury
previous surgery
stiffness
neurological symptoms
fatigue
Allow one or two submaximal practice contractions before maximal testing.
Seat the client with:
hips flexed to 90°
knees flexed to 90°
pelvis positioned against the backrest
trunk upright
thighs fully supported
feet clear of the floor if required
The pelvis should remain level throughout the assessment.
Position the testing limb so that:
the femur remains parallel with the opposite thigh
the knee aligns with the centre of the seat
the tibia remains vertical
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 placing the load cell directly over bony prominences.
Maintain the same contact point during every reassessment.
Prevent movement of:
pelvis
trunk
testing thigh
opposite limb
Only the hip should generate force throughout the contraction.
Use consistent verbal cues.
"Push your leg towards the middle."
"Build the pressure smoothly."
"Push as hard as you can."
"Hold."
"Keep breathing."
Repeat the same instructions during every reassessment.
Use:
1–2 practice trials
2–3 maximal trials
3–5 second contractions
30–60 seconds rest between trials
Record either:
highest trial, or
average of the recorded trials
Apply the same scoring method for future testing.
the pelvis rotates
the trunk leans
the thigh lifts
the knee changes position
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 strength over time
lower-limb strength profiling
athlete performance testing
monitoring response to exercise
objective progress tracking
client education
The assessment should not be used as a stand-alone diagnostic test or to determine readiness for sport.
The primary outcome is peak isometric hip external rotation force.
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 pathology
balance
movement quality
running technique
return-to-sport readiness
Higher force values generally indicate greater hip external rotation strength in the testing position.
Lower force values may be influenced by:
pain
fatigue
reduced effort
previous injury
poor familiarisation
inconsistent positioning
Interpret results by:
comparing with previous assessments
comparing left and right limbs
considering symptoms during testing
identifying movement compensations
relating findings to functional goals
Published Anker-specific normative values are currently unavailable.
Research has demonstrated excellent reliability for hip strength assessment using handheld and fixed dynamometry when standardised protocols are followed. Healthy adults generally demonstrate less than a 10% side-to-side difference in hip rotational strength. Greater asymmetries should be interpreted alongside symptoms, injury history and functional performance.
Youth
Provide additional familiarisation trials and interpret results relative to growth and physical development.
Adults
Useful for baseline strength assessment and long-term progress monitoring.
Older adults
Interpret alongside mobility, transfers, balance and daily function.
Athletes
Useful for assessing hip strength during performance profiling for running, jumping, cutting and landing sports.
Clients with persistent symptoms
Interpret alongside pain, confidence and functional performance rather than strength alone.
Common errors include:
pelvis rotating
trunk leaning
lifting the testing thigh
changing knee position
inconsistent load cell placement
inconsistent verbal instructions
Limitations include:
results are specific to the testing position
pain may reduce maximal force production
strength alone does not determine functional performance
published Anker-specific normative values remain limited
The assessment may be useful for:
establishing baseline strength
monitoring progress over time
comparing left and right limbs
athlete profiling
lower-limb performance assessment
objective reporting within Measurz
educating clients about measurable improvements
It measures maximal isometric hip external rotation strength with the hip flexed to 90 degrees.
Peak force is the primary outcome measure.
Yes. Bilateral testing allows meaningful side-to-side comparison.
No. It measures muscle strength only and should be interpreted alongside other assessment findings.
Pelvic movement changes the direction of force and reduces the repeatability of the assessment.
Measures maximal isometric hip external rotation strength.
Performed with the hip and knee flexed to 90°.
Peak force is the primary outcome measure.
Measurz provides additional force-time metrics.
Consistent positioning improves repeatability.
Compare results with previous assessments and the opposite limb rather than relying solely on published reference values.
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.
