The Hip Flexion Strength Test measures how much force a client can produce when lifting the thigh upward against resistance. It is commonly used to assess hip flexor force output in a controlled isometric setup.

Hip flexion strength can provide useful context for walking, running, sprinting, stair climbing, kicking, cycling, change of direction, lower-limb strength profiling and progress tracking. The main contributors include iliopsoas, rectus femoris, sartorius, tensor fasciae latae and other muscles that assist hip flexion or stabilise the pelvis and trunk.

The Muscle Meter is a handheld dynamometry tool used to measure force output during push, pull and isometric strength assessments. When used on its own, the Muscle Meter primarily measures peak force, which is the highest force value produced during the test. When used with Measurz, Muscle Meter data can be recorded and analysed with a broader set of strength and force-time metrics, including peak force, impulse, torque, rate of torque development, rate of force development, time to peak and fatigue index.

For routine hip flexion testing, peak force is usually the main metric. Force as a percentage of body weight may be useful if directly calculated from the client’s test force and body weight, especially for baseline comparison, side-to-side comparison and retesting. Rate of force development and time to peak may be useful when rapid thigh lift, sprinting, kicking or sport-specific force production matters. Impulse may be useful if sustained hip flexion force over a defined time window is intentionally tested. Fatigue index is only relevant if repeated or sustained hip flexion efforts are part of the protocol.

The result can support assessment reasoning and progress tracking, but it does not diagnose hip pathology, iliopsoas injury, femoral nerve involvement, hip impingement, running mechanics, groin pain or readiness for sport or work on its own.

What Is the Hip Flexion Strength Test?

The Hip Flexion Strength Test is an isometric lower-limb strength assessment where the client pushes or lifts the thigh upward into the Muscle Meter, strap or fixed setup without visible hip movement. The device is usually placed against the anterior thigh, commonly near the distal thigh above the knee depending on the chosen protocol.

The movement direction is hip flexion. The purpose of the test is to measure how much upward or forward thigh force the client can produce through the hip in a specific position.

Consistent setup matters because trunk position, pelvis position, hip angle, knee angle, device placement, strap angle, limb position and client effort can all affect the result. This test measures force output in a specific setup. It does not fully measure sprinting ability, stair function, gait, kicking ability, endurance, power, pain source, movement control or sport/work readiness on its own.

Step-by-Step Protocol / Practice

1. Prepare the client

Explain that the test measures how strongly they can lift the thigh upward into the Muscle Meter. Record baseline symptoms, hip discomfort, groin symptoms, anterior thigh symptoms, lower-back symptoms, fatigue, recent training or work exposure and confidence with maximal effort.

Use at least one submaximal practice trial so the client understands the direction of force and learns to push without trunk, pelvis or knee compensation.

2. Set the client position

A common setup is seated, supine or standing depending on the available equipment and the assessment question. Seated testing is practical and easy to repeat. Supine testing may allow more trunk control. Standing testing may be more functional but can introduce more balance and trunk compensation.

Record:

• Seated, supine, standing or other position
• Test side
• Hip angle
• Knee angle
• Pelvis position
• Trunk position
• Foot position
• Device contact point
• Whether a strap or fixed anchor was used

For seated testing, the trunk should remain upright and stable. For supine testing, the pelvis should remain level. For standing testing, the client should avoid trunk leaning or pelvic hiking.

3. Set up the device or straps

For a handheld setup, the professional holds the Muscle Meter against the anterior thigh while the client lifts or pushes upward into it. For stronger clients or improved repeatability, a strap-stabilised or fixed setup may be used.

If using a strap, record:

• Anchor point
• Strap angle
• Strap length
• Device position
• Limb position
• Whether any pre-tension was used
• Whether the anchor moved during testing

Push, pull, handheld and strap-stabilised scores should be recorded separately unless the protocol supports direct comparison.

4. Place the device, strap or handle

Place the Muscle Meter against the anterior thigh, commonly near the distal thigh above the knee. Use the same contact point at retest. Avoid uncomfortable pressure over bony or sensitive areas.

The force direction should be hip flexion. The client should push the thigh upward or forward into the device without leaning backward, hiking the pelvis or changing knee position.

5. Stabilise the position

Stabilise the pelvis and trunk so the client does not compensate with lumbar extension, trunk leaning, pelvic hiking, knee extension, ankle movement or pushing through the opposite leg.

The aim is controlled hip flexion force in the chosen position.

6. Give clear instructions

Use consistent instructions such as:

“Lift your thigh up into the device as hard as you can and hold.”
“Build up smoothly, then push hard.”
“Keep your pelvis and trunk still.”
“Do not lean back or twist your body.”
“Keep breathing.”
“Tell me if you feel pain, cramping, tingling or anything unusual.”

Use the same wording at retest where possible.

7. Record trials

Use 1–2 practice trials, then record 2–3 maximal trials. A common contraction duration is 3–5 seconds. Rest for 30–60 seconds between trials, or longer if symptoms, fatigue or cramping occur.

Record whether the final score uses the best trial or the average of recorded trials. Either approach may be used if it is applied consistently.

8. Identify invalid trials

Repeat or mark a trial as invalid if:

• The trunk leans backward
• The pelvis hikes, tilts or rotates
• The hip angle changes before the effort
• The knee angle changes
• The device slips
• The strap or anchor moves
• The client pushes through the opposite leg
• Pain or cramping limits effort
• The client starts before the device is ready
• The client holds their breath excessively
• The professional cannot hold the device steady

9. Record symptoms

Record hip pain, groin symptoms, anterior thigh symptoms, lower-back symptoms, cramping, paraesthesia, confidence, apprehension and symptom response after testing. Do not repeatedly test through high pain, worsening symptoms or strong cramping.

For retesting, match the same position, device placement, strap setup, instructions, contraction duration, rest period, scoring method and symptom recording.

Why It Is Used

The Hip Flexion Strength Test is used to quantify hip flexor force output in a repeatable setup. It may be useful for:

• Baseline lower-limb strength assessment
• Side-to-side comparison
• Monitoring change over time
• Hip flexor strength profiling
• Comparing flexion with extension where relevant
• Supporting walking, running, stair and sprinting assessment reasoning
• Supporting kicking, cycling and field sport assessment reasoning
• Workplace context where stairs, lifting the leg, climbing or repeated stepping are relevant
• Fitness and performance progress tracking
• Client education

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

What It Measures

The test primarily measures isometric hip flexion force output in the chosen setup. It reflects the client’s ability to produce upward or forward thigh force through the hip flexors while controlling pelvis and trunk position.

It may provide useful information about:

• Hip flexion force capacity
• Side-to-side force difference
• Flexion-to-extension comparison
• Confidence producing hip flexor force
• Pain response during resisted hip flexion
• Change in force over time
• Relationship between strength and related movement tasks

It does not directly measure:

• Cause of hip or groin pain
• Iliopsoas tendon status
• Hip joint pathology
• Nerve involvement
• Running mechanics
• Stair performance
• Kicking ability
• Endurance
• Readiness to return to sport or work

Understanding the Result, Reference Values and What to Look For

What a higher or lower result may suggest

A higher score may suggest greater hip flexion force output in that specific test setup. A lower score may suggest reduced hip flexion force output, but the reason should be interpreted carefully.

Lower force may be influenced by pain, apprehension, poor familiarisation, fatigue, guarding, inconsistent device placement, poor pelvis stabilisation, reduced confidence, lower-back symptoms, groin symptoms or compensation from the trunk or opposite limb.

One result should not be interpreted in isolation. Interpretation is strongest when the same setup is repeated over time and reviewed alongside symptoms, confidence, hip range of motion, extension strength, single-leg balance, gait, running exposure, sprinting, stair use or work-specific tasks.

What can influence the result

Important influences include:

• Pain
• Apprehension
• Poor familiarisation
• Fatigue
• Guarding
• Poor pelvis or trunk stabilisation
• Trunk leaning
• Pelvis hiking
• Different hip angle
• Different knee angle
• Different device placement
• Different strap angle
• Opposite-leg contribution
• Breath holding
• Client confidence
• Professional strength if using handheld resistance

Normative, reference and comparative values

Published Muscle Meter-specific universal norms for hip flexion are limited. Reference values should therefore be used as context only and not as direct targets unless the protocol is closely matched.

More user-friendly comparison data include:

• In a sample of 52 women aged 20–29 years, hip flexor force measured with handheld dynamometry was reported at approximately 38.54% of body weight. This means a 70 kg person in a similar setup would produce roughly 27 kg of force, but this should only be used as broad context unless the protocol is closely matched.
• In a large population-based lower-limb strength study, hip flexor strength was measured across adults and reported with age- and sex-specific norms. This supports the idea that hip flexion strength is influenced by age, sex, body size and testing method, rather than having one universal target.
• A broad reference-values study of 1,000 healthy participants aged 3–101 years included isometric hip strength testing and showed that age, sex and body size can influence strength values. This supports using matched comparison data when possible and avoiding one-size-fits-all targets.
• For side-to-side comparison, a difference of around 10% or more is often worth reviewing more closely, especially if it matches symptoms, previous injury, confidence changes or functional differences. This is not a strict pass/fail cut-off.
• Comparing hip flexion with hip extension can also be useful. Large differences between directions may provide context, especially when paired with symptoms, gait, sprinting, stairs, kicking or work demands.
• If force is recorded as a percentage of body weight in Measurz, use it mainly for the client’s own baseline, side-to-side comparison and retesting. Bodyweight percentage is useful only when calculated from the client’s actual test force and body weight.

These values are best used as comparison data. They can help provide context, but they should not be used as diagnostic, clearance or pass/fail cut-offs.

Practical interpretation priorities

Use this order:

1. Compare with the client’s own baseline.
2. Compare right and left sides when relevant.
3. Compare hip flexion and extension where relevant.
4. Review force relative to body weight where calculated.
5. Consider symptoms during and after testing.
6. Consider confidence and effort quality.
7. Review whether compensations were present.
8. Compare with related strength, mobility or performance tests.
9. Relate the result to walking, running, sprinting, stairs, sport, work or daily-life demands.
10. Retest under the same conditions to monitor change.
11. Do not use reference values as pass/fail criteria.

What to look at for each relevant Muscle Meter metric

Peak force
Use for maximum hip flexion force output, baseline strength, side-to-side comparison, flexion-to-extension comparison, progress tracking and comparing force across retests. Look for best score or average score, consistent setup, side-to-side difference, change from baseline, pain response and compensation during maximal effort.

Force as percentage of body weight
Use when calculated directly from test force and body weight. It may help compare the client’s result to their own baseline, the opposite side and body size. Do not treat it as a universal target unless the comparison data use a closely matched protocol.

Torque
Use only when the lever arm is measured and a more biomechanical interpretation is needed. It can help when limb length or device placement changes the raw force reading. It should not be used as normative data unless the reference data match the setup closely.

Rate of force development
Use when rapid hip flexion force matters, such as sprinting, kicking, stairs or change of direction. Look for early force production and whether rate of force development changes while peak force stays similar.

Time to peak
Use to understand whether force is produced quickly or gradually. Look for delayed peak force, faster time to peak across retests, and whether a slower time reflects caution, pain, poor cueing or an actual performance difference.

Impulse
Use only if a defined sustained force window is intentionally tested. Look for whether the client can sustain hip flexion force briefly and whether impulse improves while peak force stays similar.

Fatigue index
Use only if repeated or sustained hip flexion efforts are part of the protocol. Look for drop-off across repeated trials, symptom-related fatigue and whether fatigue improves across a training block.

Assessing and Providing Context for Different Client Populations

Youth clients
Consider growth, maturation, coordination, attention, training age and familiarisation. Practice trials are important because maximal hip flexion effort can be difficult to coordinate without trunk or pelvis movement.

Adults and general fitness clients
Use the test for baseline lower-limb strength, progress tracking and confidence with loading. Compare results with hip mobility, trunk control, lower-limb strength and general exercise goals.

Older adults
Consider walking confidence, stair climbing, transfers, balance, fatigue, rest periods and function. A lower score may provide useful context, but it should not be interpreted without functional assessment.

Athletes and sport clients
Consider sprinting, kicking, acceleration, cycling, change of direction and sport-specific hip drive. Peak force alone does not equal sport performance, but it can support a broader lower-limb strength profile.

Workplace and manual task clients
Consider stairs, ladders, stepping, carrying, prolonged standing, uneven ground, walking distance and footwear demands. Do not use one score to clear work duties.

Clients returning after injury
Use the test to monitor force output, confidence and symptom response. Strength alone should not confirm readiness.

Clients with pain or persistent symptoms
Pain, fear, guarding, fatigue, apprehension and confidence may reduce force. Record symptom response carefully and compare with related tests.

Higher body mass clients
Absolute force and force relative to body mass may both be useful. Interpret results in relation to goals, symptoms and functional demands, not assumptions about body size.

Reliability, Validity and Measurement Considerations

Repeatability improves when the same setup is used each time. Record and standardise:

• Same test position
• Same pelvis position
• Same trunk position
• Same hip angle
• Same knee angle
• Same device placement
• Same strap setup, if used
• Same anchor height and distance, if straps are used
• Same strap angle, if straps are used
• Same stabilisation
• Same instructions
• Same contraction duration
• Same rest period
• Same scoring method
• Same symptom and compensation recording

Hip flexion strength testing is setup-dependent. Small changes in trunk position, pelvis control, hip angle or device contact point can change the score. For stronger clients, handheld resistance may be limited by professional strength. Strap-stabilised or fixed setups can improve repeatability.

Common Errors and Limitations

Common errors include:

• Trunk leaning backward
• Pelvis hiking or rotating
• Knee angle changing
• Opposite-leg pushing
• Device placement changing between trials
• Strap or anchor movement
• Breath holding
• Testing through high pain or cramping
• Comparing different protocols directly
• Treating the score as a diagnosis

Limitations include:

• Testing is setup-dependent
• Manual resistance may be limited by professional strength
• Muscle Meter-specific universal norms may be limited
• Published hip flexion norms vary by device, position and population
• Pain, fear or guarding can reduce force output
• Peak force does not measure endurance or movement quality
• Strong symmetry does not automatically indicate readiness for sport or work

Practical Applications

The Hip Flexion Strength Test may be useful for:

• Baseline hip strength assessment
• Side-to-side comparison
• Monitoring response to exercise or intervention
• Comparing flexion with extension where relevant
• Supporting walking, sprinting, stairs and kicking assessment reasoning
• Comparing with hip mobility, trunk control and functional tasks
• Sport and workplace strength profiling
• Client education
• Fitness and performance progress tracking

Ideas to Make the Result Better

If force is low on both sides, consider assessing hip range of motion, hip extension strength, trunk control, gait, stairs, recent workload and confidence with loading.

If one side is much lower, compare with symptoms, injury history, hip mobility, extension strength, single-leg tasks, running exposure and work or sport demands.

If pain or cramping limits the result, record symptom location and review whether device placement, test position or effort level needs modification.

If force is good but function is limited, compare with gait, stairs, sprinting mechanics, kicking, cycling, workload and task exposure.

If the client is improving, keep the same test setup and monitor whether force, symptoms, confidence and function improve together.

Recommended Standard Protocol Summary

Position: Seated, supine or standing, with pelvis and trunk controlled
Start position: Hip and knee position recorded
Joint or trunk angle: Record hip, knee, pelvis and trunk position
Trials: 1–2 practice trials, then 2–3 recorded trials
Contraction duration: 3–5 seconds
Rest: 30–60 seconds between efforts
Metric: Peak force, plus percentage of body weight if directly calculated
Attachment or device setup: Muscle Meter against anterior thigh, with consistent contact point; strap-stabilised if used
Final score: Best trial or average of trials
Key retesting requirement: Same body position, pelvis control, hip angle, device placement, instructions, contraction duration, rest and scoring method

FAQs

What does the Hip Flexion Strength Test measure?

It measures isometric hip flexion force output in a specific test setup.

Which muscles contribute to hip flexion?

The main contributors include iliopsoas, rectus femoris, sartorius and tensor fasciae latae, with trunk and pelvis control also influencing the test.

Should the result be recorded as percentage of body weight?

It can be if you calculate it directly from test force and body weight. This is useful for internal comparison, especially when tracking change over time.

Are there universal hip flexion norms for the Muscle Meter?

Published universal Muscle Meter norms for this exact protocol appear limited. Baseline, side-to-side comparison and repeated testing are usually more useful.

What numerical values are available for comparison?

Published handheld dynamometry data in young women reported hip flexion force around 38.54% body weight. This is useful context but not a direct Muscle Meter target unless the setup is closely matched.

Can this test diagnose a hip flexor injury or hip pathology?

No. It can measure force output and symptom response, but it does not diagnose a condition or explain symptoms on its own.

What can make the result unreliable?

Trunk leaning, pelvis hiking, different hip angles, device slipping, pain, fatigue and inconsistent instructions can affect results.

What should be recorded in Measurz?

Record side, body position, hip angle, knee angle, device placement, peak force, percentage bodyweight if calculated, symptoms, compensations, confidence, scoring method and related findings.

Key Takeaways

• The Hip Flexion Strength Test measures isometric hip flexion force output.
• Peak force is usually the main routine Muscle Meter metric.
• Published comparison data include hip flexion force around 38.54% body weight in young women, but protocols vary.
• Percentage of body weight should only be used when calculated directly from force and body weight or when comparison data are reported that way.
• Baseline comparison, side-to-side comparison and retesting consistency are usually more useful than broad norms.
• Reference values provide context, not diagnostic or clearance cut-offs.
• Measurz should capture setup, symptoms, bodyweight-normalised values where calculated, compensations and retesting conditions.

References

Daloia, L. M. T., Leonardi-Figueiredo, M. M., Martinez, E. Z., & Mattiello, S. M. (2018). Isometric muscle force assessment of the hip muscles in healthy women: A reliability and normative data study. Journal of Bodywork and Movement Therapies, 22(2), 420–427.

Harbo, T., Brincks, J., & Andersen, H. (2012). Maximal isokinetic and isometric muscle strength of major muscle groups related to age, body mass, height, and sex in 178 healthy subjects. European Journal of Applied Physiology, 112(1), 267–275. https://doi.org/10.1007/s00421-011-1975-3

McKay, M. J., Baldwin, J. N., Ferreira, P., Simic, M., Vanicek, N., Burns, J., & 1000 Norms Project Consortium. (2017). Normative reference values for strength and flexibility of 1,000 children and adults. Neurology, 88(1), 36–43. https://doi.org/10.1212/WNL.0000000000003466

Russo, C. R., Ricca, M., Ferrucci, L., & others. (2020). Lower-limb muscle strength: Normative data from an observational population-based study. BMC Musculoskeletal Disorders, 21, 89. https://doi.org/10.1186/s12891-020-3098-7

World Physiotherapy. (2019). Normative values for isometric hip muscle force assessed by hand-held dynamometry. World Physiotherapy Congress Proceedings.