Ankle Orthopaedic Test: Jack’s Test

Jack’s Test, also called the Hubscher manoeuvre, is a weight-bearing foot assessment used to observe how the medial longitudinal arch responds when the hallux is passively dorsiflexed. The test is commonly used to support assessment reasoning around the windlass mechanism, first metatarsophalangeal joint function and flexible versus more rigid flatfoot presentations.

A positive or abnormal finding may suggest reduced arch elevation, increased hallux dorsiflexion resistance, discomfort, or a less responsive windlass mechanism. However, Jack’s Test does not confirm a diagnosis on its own and should be interpreted alongside history, symptoms, foot posture, gait, strength, range of motion and other assessment findings.

Introduction

Jack’s Test is a practical foot and ankle special test used to assess the response of the medial longitudinal arch during passive dorsiflexion of the hallux in weight-bearing. It is also known as the Hubscher manoeuvre.

The test is based on the windlass mechanism. When the hallux dorsiflexes, tension increases through the plantar fascia, which may help elevate the medial longitudinal arch and contribute to foot stiffness during propulsion. In a typical response, passive dorsiflexion of the hallux in standing produces visible elevation of the medial arch and may be accompanied by subtle rearfoot and tibial movement.

In practice, Jack’s Test is often used when assessing foot posture, flatfoot presentations, hallux limitus, plantar fascia-related symptoms and lower-limb mechanics. It can be helpful as an educational and observational test, but it should not be used as a stand-alone diagnostic tool.

Evidence suggests caution is needed when interpreting the test. Static hallux dorsiflexion in standing may not accurately predict dynamic first MTP joint motion during gait. This means Jack’s Test should be considered one part of a broader assessment rather than proof of how the foot behaves during walking, running or sport.

Quick Summary

Test name: Jack’s Test / Hubscher manoeuvre
Region: Foot and ankle
Primary purpose: Observe windlass mechanism response during hallux dorsiflexion
Commonly associated presentations: Flexible flatfoot, reduced arch stiffness, functional hallux limitus, plantar fascia-related symptoms
Positive finding: Limited arch elevation, excessive resistance, pain reproduction or poor windlass response during hallux dorsiflexion
Negative finding: Hallux dorsiflexion produces expected arch elevation without relevant symptom reproduction
Best used with: Foot posture assessment, first MTP range of motion, gait observation, calf strength, balance, hop testing and symptom history
Main limitation: It does not confirm or exclude a condition on its own.

What Is Jack’s Test?

Jack’s Test is a weight-bearing clinical assessment where the professional passively dorsiflexes the client’s hallux while observing the foot’s response.

The main observed response is whether the medial longitudinal arch rises as the hallux is lifted. This response is commonly interpreted as a sign that the windlass mechanism can be engaged in standing.

The test may also be used to observe:

• Hallux dorsiflexion range in weight-bearing
• Resistance to hallux dorsiflexion
• Medial arch response
• Rearfoot movement
• Tibial rotation response
• Symptom reproduction
• Side-to-side differences

Jack’s Test is sometimes described as a flexible flatfoot test. If the arch rises when the hallux is dorsiflexed, this may suggest that the foot posture is flexible rather than fixed. If the arch does not rise, the finding may suggest a less responsive windlass mechanism or a more rigid foot posture, but further assessment is required.

Why It Is Used

Jack’s Test may be used to support assessment reasoning around:

• Windlass mechanism function
• Hallux dorsiflexion in weight-bearing
• Flexible flatfoot presentations
• Medial longitudinal arch behaviour
• Functional hallux limitus
• Plantar fascia load sensitivity
• First MTP joint contribution to gait and propulsion
• Foot posture and lower-limb alignment
• Orthotic, footwear or load-management discussions within professional scope

The test is useful because it is quick, visual and easy to explain to clients. It can help professionals show how hallux movement and arch behaviour may be connected.

However, the test should not be used to confirm plantar fasciopathy, posterior tibial tendon dysfunction, flatfoot deformity or hallux limitus on its own.

What It Assesses

Jack’s Test assesses the observed response of the foot when the hallux is passively dorsiflexed in weight-bearing.

It may provide information about:

• Medial longitudinal arch response
• Hallux dorsiflexion behaviour under load
• Windlass mechanism response
• First MTP joint mobility in standing
• Symptom response to hallux dorsiflexion
• Side-to-side differences
• Whether a flatfoot posture appears flexible or less flexible

It does not directly assess:

• Plantar fascia tissue integrity
• Posterior tibial tendon integrity
• Dynamic gait mechanics with certainty
• Foot strength
• Balance
• Running performance
• Imaging findings
• Injury diagnosis
• Readiness for sport or work

Who It Is Useful For

Jack’s Test may be useful for clients with:

• Flatfoot or low-arch presentation
• Foot fatigue during standing or walking
• Plantar heel symptoms
• First MTP stiffness or discomfort
• Reduced push-off confidence
• Footwear or orthotic assessment needs
• Lower-limb movement concerns
• Sport or work tasks involving repeated foot loading

It may also be useful for students and professionals learning how foot mechanics, hallux dorsiflexion and arch behaviour interact during assessment.

When to Use This Test

Consider using Jack’s Test when:

• The client presents with a low medial longitudinal arch
• You want to observe whether the arch elevates with hallux dorsiflexion
• First MTP joint function is relevant to the assessment
• Plantar fascia-related symptoms are being explored
• Foot posture may influence movement or loading
• Side-to-side foot behaviour is relevant
• You are building a broader foot and ankle assessment profile

Jack’s Test is best used after observing standing posture and before or alongside gait, balance, strength and range of motion assessment.

When Not to Use or When to Be Cautious

Use caution or avoid the test when:

• Hallux dorsiflexion is acutely painful
• The first MTP joint is highly irritable
• There is recent trauma to the toe, forefoot or foot
• There is suspected fracture or acute inflammatory flare
• The client cannot tolerate weight-bearing
• The client cannot stand safely
• The test position causes dizziness or instability
• The client reports neurological symptoms requiring further assessment

Stop the test if symptoms increase sharply, the client becomes uncomfortable, or the test cannot be performed safely.

Equipment Required

Jack’s Test usually requires no equipment.

Optional equipment may include:

• Measurz app
• Pain rating scale
• Video recording for education or comparison
• Foot posture notes
• Goniometer if measuring first MTP dorsiflexion separately
• Force gauge if performing a quantified hallux dorsiflexion resistance variation

Step-by-Step Protocol / Practice

Setup

Ask the client to stand barefoot on a flat surface. The feet should be relaxed in a comfortable standing position.

Observe the resting posture of the foot before touching the hallux.

Record whether the client is in:

• Barefoot standing
• Shoes
• Orthotics
• Natural stance
• Narrow stance
• Single-leg stance variation, if used

For standard use, barefoot relaxed standing is preferred.

Client position

The client stands upright with:

• Both feet flat on the floor
• Weight evenly distributed
• Knees relaxed but not flexed excessively
• Hips facing forward
• Arms relaxed or supported lightly if balance is an issue
• Eyes forward

The client should not actively grip the floor with the toes.

Examiner/professional position

The professional stands or kneels in front of, beside or slightly medial to the tested foot, depending on comfort and visibility.

The professional should be able to:

• Stabilise the foot if needed
• Lift the hallux safely
• Observe the medial arch
• Observe the rearfoot
• Ask about symptoms

Hand placement

Use one hand to hold the hallux near the proximal phalanx.

The other hand may be used to lightly stabilise the first metatarsal or observe foot movement. Avoid excessive force or painful gripping.

Stabilisation

Do not force the foot into a corrected arch position. The goal is to observe the natural response.

If needed, lightly stabilise the first ray or forefoot so the movement is controlled, but avoid changing the result by manually lifting the arch.

Movement or force direction

Passively dorsiflex the hallux.

The movement direction is upward extension of the first MTP joint while the foot remains weight-bearing.

Move slowly and smoothly.

Instructions

Tell the client:

“Stay relaxed and keep your foot flat. I am going to gently lift your big toe and observe how your arch responds. Let me know if this reproduces any symptoms.”

Positive finding

A positive or abnormal finding may include:

• Limited or absent medial arch elevation
• Marked resistance to passive hallux dorsiflexion
• Reproduction of relevant plantar fascia, first MTP or medial foot symptoms
• Asymmetrical response compared with the other side
• Poor rearfoot or tibial response when compared with expected movement

The specific reason for calling the test positive should be recorded.

Negative finding

A negative finding may include:

• Hallux dorsiflexion occurs without relevant symptom reproduction
• The medial arch elevates as expected
• The response is similar side to side
• The client reports no familiar pain or concerning symptoms

A negative result does not fully exclude foot or first MTP-related problems.

Stopping criteria

Stop the test if:

• Pain increases sharply
• The client asks to stop
• The first MTP joint feels blocked or highly painful
• Balance becomes unsafe
• Neurological symptoms occur
• The test cannot be performed without forcing movement

Safety notes

The test should be gentle. Avoid forcing hallux dorsiflexion, especially when the client reports first MTP pain, recent injury or high irritability.

Positive and Negative Test Interpretation

A positive Jack’s Test may suggest that the windlass mechanism is less responsive in standing, the first MTP joint is limited under load, or the foot does not show expected arch elevation during passive hallux dorsiflexion. If the test reproduces familiar plantar heel or medial foot symptoms, this may increase suspicion that hallux dorsiflexion and plantar fascia tension are relevant to the client’s presentation.

However, a positive test does not confirm plantar fasciopathy, functional hallux limitus, flatfoot pathology or posterior tibial tendon dysfunction. Pain, stiffness, guarding, foot posture, soft tissue sensitivity, footwear history and loading tolerance may all influence the result.

A negative test may suggest that passive hallux dorsiflexion in standing produces an expected arch response and does not reproduce familiar symptoms. This may decrease suspicion that the windlass mechanism is a major contributor to the current symptoms, especially when other findings are also normal.

However, a negative test does not fully exclude foot or ankle pathology. Some clients may still have symptoms during walking, running, hopping or sport-specific tasks even if Jack’s Test appears normal in standing.

The test is more meaningful when interpreted with:

• History
• Symptom location
• First-step pain behaviour
• First MTP range of motion
• Foot posture
• Calf capacity
• Balance
• Gait
• Hop or running assessment
• Footwear and load history
• Related special tests

Sensitivity, Specificity and Diagnostic Accuracy

At the time of writing, high-quality peer-reviewed diagnostic accuracy evidence reporting sensitivity, specificity or likelihood ratios for Jack’s Test as a stand-alone diagnostic test appears limited.

This means Jack’s Test should be used as an educational and assessment reasoning tool rather than as a stand-alone diagnostic test.

Relevant evidence and limitations include:

• Jack’s Test is widely used to observe the windlass mechanism and first MTP dorsiflexion response in standing.
• Evidence has questioned whether weight-bearing passive hallux dorsiflexion in standing predicts hallux dorsiflexion during walking.
• Static test behaviour may not reflect dynamic gait, running or sport loading.
• Positive and negative findings should be interpreted alongside other assessment findings.
• No single Jack’s Test finding should be used to confirm or exclude a condition.

Where diagnostic values are not available, document the finding descriptively rather than assigning diagnostic certainty.

Reliability and Validity

The reliability and validity of Jack’s Test depend on how the test is performed and what the professional is trying to infer.

The test has face validity as an observation of arch response during hallux dorsiflexion in standing. It is practical for observing whether the medial arch elevates during passive hallux dorsiflexion.

However, its validity as a predictor of dynamic first MTP behaviour during gait is limited. Research has reported that weight-bearing passive hallux dorsiflexion in standing is not necessarily related to hallux dorsiflexion during walking.

Reliability may improve when the professional standardises:

• Client stance
• Barefoot versus footwear condition
• Hallux grip
• Speed of dorsiflexion
• Amount of force
• Arch observation criteria
• Symptom recording
• Side-to-side comparison

A quantified hallux dorsiflexion resistance variation using a force gauge may improve measurement objectivity, but this is a different approach from the traditional observational Jack’s Test.

Common Errors and Limitations

Common errors include:

• Forcing hallux dorsiflexion
• Not recording symptoms
• Focusing only on arch height
• Ignoring first MTP pain
• Ignoring side-to-side difference
• Testing in shoes without documenting it
• Comparing barefoot and shod testing directly
• Assuming the test predicts gait mechanics
• Calling the test diagnostic
• Not considering foot posture, calf capacity or gait findings

Limitations include:

• Static standing may not reflect walking or running
• Arch response is partly subjective
• Force applied by the professional may vary
• Pain may limit test interpretation
• Hallux stiffness may alter the result
• Foot posture may influence the visual response
• Evidence for diagnostic accuracy is limited
• The test should not be used alone for decision-making

Practical Applications

Jack’s Test may be useful for:

• Teaching the windlass mechanism
• Observing arch response
• Comparing left and right foot behaviour
• Exploring hallux dorsiflexion under load
• Supporting flexible versus less flexible foot posture reasoning
• Adding context to plantar fascia-related symptoms
• Supporting footwear and orthotic discussions within scope
• Building a broader foot and ankle assessment profile

In Measurz, Jack’s Test can be recorded alongside foot posture, ankle range of motion, calf strength, balance, hop testing, pain location and gait notes.

How to Record This in Measurz

Record the following:

• Test name: Jack’s Test / Hubscher manoeuvre
• Side tested
• Result: positive, negative, unclear or unable to test
• Whether testing was barefoot or in footwear
• Client position
• Hallux dorsiflexion response
• Arch response
• Symptom location
• Pain score
• Symptom quality
• Resistance to dorsiflexion
• Side-to-side comparison
• Confidence in result
• Irritability
• Compensations
• Reason for stopping, if relevant
• Related findings
• Notes on interpretation
• Retest date if relevant

Recording these details improves repeatability, communication, client education, assessment reasoning and reporting quality.

Related Tests / Internal Links

• First MTP joint range of motion
• Foot Posture Index
• Navicular Drop Test
• Windlass Test
• Supination Resistance Test
• Single-leg heel raise
• Calf raise endurance test
• Ankle dorsiflexion range of motion
• Balance testing
• Hop testing
• Gait observation

FAQs

Is Jack’s Test the same as the Hubscher manoeuvre?

Yes. Jack’s Test is commonly referred to as the Hubscher manoeuvre.

What does Jack’s Test assess?

It assesses the observed response of the medial longitudinal arch when the hallux is passively dorsiflexed in weight-bearing.

What is a positive Jack’s Test?

A positive or abnormal finding may include limited arch elevation, increased resistance, symptom reproduction or a side-to-side difference.

Does Jack’s Test diagnose flatfoot?

No. It may support assessment reasoning around flexible or less flexible foot posture, but it does not diagnose flatfoot on its own.

Does Jack’s Test diagnose plantar fasciopathy?

No. It may reproduce plantar fascia-related symptoms, but it does not confirm plantar fasciopathy.

Can Jack’s Test predict walking mechanics?

Not reliably on its own. Static standing hallux dorsiflexion may not match dynamic hallux movement during walking.

Should the test be painful?

No. The test should be gentle. Familiar symptom reproduction should be recorded, but the hallux should not be forced.

Should I compare both sides?

Yes. Side-to-side comparison can make the result more meaningful.

Key Takeaways

Jack’s Test assesses the foot’s response to passive hallux dorsiflexion in weight-bearing.

It is commonly used to observe the windlass mechanism and arch response.

A positive finding may increase suspicion that hallux dorsiflexion or windlass function is relevant to the presentation.

A negative finding does not fully exclude foot or first MTP-related issues.

Diagnostic accuracy evidence for the test as a stand-alone diagnostic tool appears limited.

The result should be recorded carefully and interpreted with other Measurz assessment findings.

References

Durrant, B., & Chockalingam, N. (2009). Functional hallux limitus: A review. Journal of the American Podiatric Medical Association, 99(3), 236–243. PMID: 19448175

Gómez-Carrión, Á., Sánchez-Gómez, R., Reguera-Medina, J. M., Martínez-Sebastián, C., Márquez-Reina, S., Coheña-Jiménez, M., & Moisan, G. (2024). Effect of using a kinetic wedge during the hallux dorsiflexion resistance test in asymptomatic individuals. BMC Musculoskeletal Disorders. doi:10.1186/s12891-024-07520-z

Halstead, J., & Redmond, A. C. (2006). Weight-bearing passive dorsiflexion of the hallux in standing is not related to hallux dorsiflexion during walking. Journal of Orthopaedic & Sports Physical Therapy, 36(8), 550–556. doi:10.2519/jospt.2006.2136

Hicks, J. H. (1954). The mechanics of the foot. II. The plantar aponeurosis and the arch. Journal of Anatomy, 88(1), 25–30.

Jack, E. A. (1953). Naviculo-cuneiform fusion in the treatment of flat foot. The Journal of Bone and Joint Surgery. British Volume, 35-B(1), 75–82.

Sánchez-Gómez, R., Gómez-Carrión, Á., Martínez-Sebastián, C., Reguera-Medina, J. M., Márquez-Reina, S., & Coheña-Jiménez, M. (2024). Biomechanical effect on Jack’s Test on barefoot position, regular socks and biomechanical socks. Life, 14(2), 248. doi:10.3390/life14020248