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.
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.
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.
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.
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.
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
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.
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.
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.
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
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.
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.
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
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.
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.
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.
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.”
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.
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.
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
The test should be gentle. Avoid forcing hallux dorsiflexion, especially when the client reports first MTP pain, recent injury or high irritability.
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
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.
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 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
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.
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.
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
Yes. Jack’s Test is commonly referred to as the Hubscher manoeuvre.
It assesses the observed response of the medial longitudinal arch when the hallux is passively dorsiflexed in weight-bearing.
A positive or abnormal finding may include limited arch elevation, increased resistance, symptom reproduction or a side-to-side difference.
No. It may support assessment reasoning around flexible or less flexible foot posture, but it does not diagnose flatfoot on its own.
No. It may reproduce plantar fascia-related symptoms, but it does not confirm plantar fasciopathy.
Not reliably on its own. Static standing hallux dorsiflexion may not match dynamic hallux movement during walking.
No. The test should be gentle. Familiar symptom reproduction should be recorded, but the hallux should not be forced.
Yes. Side-to-side comparison can make the result more meaningful.
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.
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
