The Ankle Inversion Muscle Meter test measures isometric force output during ankle inversion. The client pushes the inside of the foot into a Muscle Meter, handheld dynamometer or fixed dynamometry setup while the professional controls the ankle position and records force. Higher scores may suggest greater inversion force capacity in that specific test position, while lower scores may reflect reduced force output, pain, fatigue, apprehension, unfamiliarity or poor stabilisation. The result should be interpreted alongside symptoms, ankle range of motion, balance, gait, sport or work demands and repeated testing.
Ankle inversion strength contributes to foot control, medial ankle support, walking, running, cutting, landing, balance and lower-limb force transfer.
The main muscle contributors during ankle inversion include:
tibialis posterior
tibialis anterior
flexor hallucis longus
flexor digitorum longus
medial ankle and foot stabilisers
A Muscle Meter or handheld dynamometer can help quantify ankle inversion force rather than relying only on manual muscle testing grades. This can make baseline testing, side-to-side comparison and progress tracking more objective.
This article follows the Measurz Muscle Meter and handheld dynamometer article optimiser prompt, including the required focus on protocol clarity, push and pull testing, scoring units, body-weight percentage, population-specific interpretation, reliability, validity, measurement error and Measurz recording guidance.
The test does not diagnose ankle instability, tendon injury, nerve involvement or return-to-sport readiness on its own. It is a strength measurement that should be interpreted with the broader assessment.
The Ankle Inversion Strength Test measures how much force a client can produce when turning the sole of the foot inward against a fixed or resisted device.
In a Muscle Meter or handheld dynamometer setup, the client usually performs a make test:
the device stays still
the client gradually builds force
the client pushes into the device as hard as safely possible
the peak or average force is recorded
For this article, the default method is a push test, where the client pushes the medial side of the foot into the device. A strap-stabilised setup may also be used to reduce the influence of assessor strength and improve consistency.
Research on handheld dynamometry for foot inversion and eversion shows that reliability and validity depend strongly on body position, stabilisation and method. A study comparing three positions for inversion and eversion strength found that seated testing was clinically useful, while belt-stabilised testing improved consistency and comparability.
The Muscle Meter is a practical force-testing tool used to measure isometric strength during specific movements. It may be used similarly to a handheld dynamometer or load-cell-based strength device, depending on the setup.
For ankle inversion, the Muscle Meter can help record:
peak force
best trial
average trial
left-right comparison
percentage of body weight, if calculated
pain or symptom response during force production
progress over repeated tests
In Measurz use, consistency matters more than chasing one perfect number. Use the same:
test position
ankle angle
device placement
attachment
stabilisation method
contraction duration
instructions
unit of measurement
scoring method
Do not compare scores from different devices, attachments or protocols as if they are interchangeable.
Ankle inversion strength testing may be useful because the ankle invertors contribute to foot control, arch support, balance, walking and sport movements.
The test can help professionals:
establish a baseline strength score
compare left and right ankle inversion force
monitor progress after a training or rehabilitation block
track changes after ankle pain, injury or reduced activity
identify whether force output is limited by pain, fatigue or confidence
support client education with objective data
compare ankle strength with related function such as gait, balance, hopping or change of direction
record consistent strength information in Measurz
The test should support assessment reasoning. It should not be used as a stand-alone diagnostic or clearance measure.
The Ankle Inversion Strength Test measures isometric force output in a specific ankle and foot position.
It may provide insight into:
ankle inversion force capacity
medial ankle and foot force production
side-to-side force differences
confidence producing force
pain response during resisted inversion
change in force over time
relationship between strength and function
It does not directly measure:
ankle inversion range of motion
subtalar joint mobility
tibialis posterior tendon integrity
ligament integrity
chronic ankle instability
foot posture
balance
endurance
power
running or cutting quality
readiness to return to running, sport or work
Explain the test clearly.
Example wording:
“We are going to measure how much force you can produce when turning your foot inward into the Muscle Meter. This is a strength test, not a diagnosis. Tell me if you feel pain, cramping, numbness or anything unusual.”
Use:
Muscle Meter, handheld dynamometer or fixed dynamometry device
flat pad, strap pad or suitable attachment for the medial foot
optional strap or fixed frame for stabilisation
chair, plinth or bench
pain rating scale
Measurz recording workflow
Default method:
Push test / make test
The client pushes the medial side of the foot inward into the stationary device.
The professional holds or fixes the device in place.
Alternative method:
Strap-stabilised fixed test
The device or strap resists the inversion force.
This can reduce the influence of assessor strength.
Push and pull values should be recorded separately. Do not compare values unless the protocol supports that comparison.
Common seated position:
seated on a chair or plinth
hip flexed around 90 degrees
knee flexed around 90 degrees
foot off the ground or lightly supported depending on setup
ankle near neutral
trunk upright
hands resting comfortably
Alternative long-sitting position:
client long-sitting
knee extended or slightly flexed depending on protocol
ankle near neutral
lower leg stabilised
Record the exact position used.
The professional should position themselves to:
stabilise the lower leg
keep the device aligned with the force direction
prevent device slipping
avoid being overpowered by the client
observe compensations
read the device safely
Record:
knee position: flexed or extended
ankle position: neutral, plantarflexed or dorsiflexed
foot position: neutral starting alignment
subtalar position if controlled
For routine testing, ankle neutral is often practical, but the chosen position should be repeated at retest.
Place the device against the medial side of the foot.
Common practical landmarks include:
medial forefoot
medial midfoot
around the first metatarsal region
strap across medial forefoot, depending on attachment
Avoid placing the device so far forward that the toes dominate the effort.
Record the landmark used.
Stabilise:
distal tibia or lower leg
knee position
thigh if needed
device position
foot starting alignment
Avoid:
hip rotation
knee movement
whole-leg pushing
ankle plantarflexion compensation
toe gripping
foot sliding
device movement
A fixed or belt-stabilised setup can reduce the influence of assessor strength and improve repeatability. Research on foot inversion and eversion dynamometry used belt stabilisation to compare handheld dynamometry with isokinetic dynamometry and found that protocol and position affected reliability and comparability.
The client attempts to invert the ankle:
“turn the sole of your foot inward”
force is directed medially into the device
the device resists the movement
the ankle should remain isometric, with minimal visible movement
Use consistent instructions:
“Build up gradually.”
“Push the inside of your foot into the device.”
“Push as hard as you safely can.”
“Hold the effort.”
“Keep breathing.”
“Do not twist your whole leg.”
“Tell me if you feel pain or symptoms.”
Use:
1–2 submaximal practice trials
1 familiarisation maximal effort if needed
consistent cueing
enough rest before recorded trials
This is especially important for youth clients, older adults and clients unfamiliar with dynamometry.
A practical protocol:
2–3 recorded trials per side
3–5 second contraction
30–60 seconds rest between trials
test the same side first each time
record best trial or average of trials
Use the same method at retest.
Use enough rest to reduce fatigue:
30 seconds minimum for low-irritability testing
60 seconds or more for stronger clients, older adults or symptomatic clients
longer rest if pain, cramping or fatigue affects effort
Repeat or mark a trial invalid if:
device slips
foot position changes
the client rotates the whole leg
toe flexion dominates the effort
ankle plantarflexion changes the direction
pain limits effort unexpectedly
the client does not understand the task
compensations make the result unreliable
the professional cannot hold the device steady
Stop testing if the client reports:
sharp pain
worsening neurological symptoms
cramping that does not settle
dizziness or distress
numbness or unusual symptoms
inability to produce safe effort
For clients with acute medial ankle pain, suspected tendon irritation, significant swelling or severe pain, use a lower-intensity test or defer maximal testing.
Retest using the same:
position
device
attachment
foot placement
joint angle
stabilisation
side order
trial number
contraction duration
rest period
scoring method
unit of measurement
Ankle inversion can be tested using different setups.
A push test usually means the client pushes the medial foot into the Muscle Meter or handheld dynamometer.
Benefits:
easy to set up
practical in gym, clinic or field settings
useful for baseline testing
works well for many clients
Limitations:
assessor strength can influence the result
device movement can reduce reliability
stronger clients may overpower the tester
foot placement must be consistent
A pull test may use a strap, cable, handle or fixed attachment where the client pulls the foot inward against a fixed resistance.
Benefits:
may reduce assessor strength influence
may improve repeatability when fixed well
useful for stronger clients or repeated monitoring
Limitations:
requires more setup
strap placement must be consistent
values may differ from push testing
should be recorded separately
A fixed setup can improve consistency because the device is anchored rather than held by the assessor.
This is often helpful when:
clients are strong
repeated testing matters
the assessor cannot hold the device still
side-to-side precision is important
multiple staff need to test consistently
Push, pull and strap-stabilised scores should not be mixed unless the protocol and evidence support comparison.
Record the exact unit displayed by the device:
kilograms, kg
pounds, lb
Newtons, N
kilograms-force, kgf
pounds-force, lbf
percentage of body weight, %BW
In strict physics terms, force is measured in Newtons, while kilograms are a unit of mass. In applied dynamometry, many devices display force-equivalent values in kilograms. For Measurz recording, use the unit shown by the device and keep it consistent at retest.
Record whether the score represents:
peak force
best trial
average of trials
left and right values
absolute score
body-weight-normalised score
A higher score may suggest:
greater inversion force output in the tested position
improved ability to generate force against resistance
better side-to-side symmetry if the opposite side is similar
progress from baseline if protocol is unchanged
A lower score may suggest:
reduced inversion force output in that position
pain-limited effort
fatigue
guarding
reduced confidence
poor familiarisation
poor stabilisation
altered motor control
symptoms affecting effort
A lower score does not explain the reason for the difference on its own.
Side-to-side comparison can be useful when one side is affected.
Record:
left score
right score
difference in kg, lb or N
percentage difference
affected side
dominant side if relevant
Symmetry is useful, but symmetry alone does not confirm readiness or explain symptoms.
Percentage of body weight expresses force relative to body mass.
If the device displays kilograms:
Force in kg ÷ body mass in kg × 100 = % body weight
If the device displays pounds:
Force in lb ÷ body weight in lb × 100 = % body weight
If the device displays Newtons:
Force in N ÷ body weight in N × 100 = % body weight
Example:
client body mass = 80 kg
ankle inversion score = 20 kg
20 ÷ 80 × 100 = 25% body weight
This can help compare force relative to the body the client needs to move, but it is not a universal pass/fail threshold.
The score does not prove:
diagnosis
cause of weakness
tibialis posterior pathology
ligament injury
chronic ankle instability
nerve injury
readiness to run
readiness for sport
readiness for work duties
effectiveness of one intervention by itself
Published ankle inversion strength values exist, but they are highly protocol-specific.
A 2025 systematic review of lower-limb handheld dynamometry reference values reported that HHD reference values are increasingly available, but values vary by protocol, muscle group, position, population and reporting method. This means ankle inversion scores should only be compared with reference data that closely match the test setup.
A 2016 study of foot inversion and eversion strength using handheld dynamometry compared sitting, supine and side-lying positions and found that testing position and stabilisation affected reliability and comparability. This is directly relevant to Muscle Meter ankle inversion testing because it shows why the exact protocol must be documented.
A 2021 review of adult handheld dynamometry reference values concluded that the literature still has gaps, especially around clearly described protocols, strength units and known psychometric properties.
For this exact Measurz Muscle Meter ankle inversion setup, high-quality peer-reviewed normative or body-weight percentage reference values that match every device, position and population appear limited.
Use practical comparison guidance:
compare left and right sides
compare with the client’s own baseline
use the same device and unit
calculate % body weight if useful
compare only with matched protocols where available
interpret with pain, foot posture, balance and activity demands
avoid universal pass/fail thresholds
Body-weight percentage may be useful for:
comparing clients of different body sizes
monitoring changes when body mass changes
interpreting force for bodyweight and sport tasks
running, stepping, balance and change-of-direction contexts
athlete monitoring when matched benchmarks exist
Limitations:
% body weight is test-specific
it should not be compared across different muscle groups
it should not be compared across different devices unless protocols match
it is not a universal readiness marker
it should be interpreted with symptoms, function and goals
In youth clients, ankle inversion strength can be influenced by:
growth
maturation
coordination
attention
motivation
training age
body size changes
familiarisation with testing
A higher score may suggest greater force output in the test position, but improvements may reflect growth, coordination or confidence as much as strength adaptation.
Adult reference values should not be applied to youth unless evidence clearly supports the comparison.
For adults and general fitness clients, ankle inversion Muscle Meter testing is often most useful for:
baseline comparison
progress tracking
left-right comparison
education
monitoring response to training
A higher score may suggest greater force output. A lower score may suggest reduced force capacity, but it should be interpreted with activity level, symptoms, range of motion and testing familiarity.
In older adults, ankle inversion strength may be relevant to:
walking
balance
foot placement
uneven-ground confidence
stair use
daily movement
Foot and ankle characteristics are associated with balance and functional ability in older people, but strength scores should be interpreted as part of a broader picture rather than as a single predictor of function.
Older adults may need:
slower ramp-up
more familiarisation
longer rest
cautious effort cues
careful symptom monitoring
Interpret results alongside balance, gait, sit-to-stand performance, confidence and daily function.
For athletes, ankle inversion strength may be relevant to:
change of direction
landing control
ankle stiffness and control
cutting and pivoting
running on uneven ground
return-to-training monitoring
A higher force score may suggest greater capacity in that test position, but performance also depends on:
rate of force development
impulse
power
coordination
reactive strength
fatigue resistance
sport skill
workload tolerance
In workplace settings, ankle inversion strength may provide context for:
walking
stairs
ladders
uneven ground
prolonged standing
carrying tasks over variable surfaces
It should be interpreted alongside job demands, footwear, fatigue, symptoms, balance, gait and task exposure. One force score does not clear a worker for full duties.
For clients returning after ankle sprain, foot pain or lower-limb injury, inversion testing may help monitor:
side-to-side force recovery
confidence producing force
pain during resisted inversion
baseline-to-retest change
relationship with balance, hopping and gait
A side-to-side difference may provide useful monitoring information, but symmetry alone does not confirm readiness or explain symptoms.
Pain may reduce force output through:
guarding
apprehension
reduced confidence
fatigue
symptom flare
unfamiliarity with loading
A lower score may reflect reduced force capacity, pain, guarding, apprehension, fatigue or test unfamiliarity. It should not be used to explain the cause of pain on its own.
Always record pain during the test.
Higher body mass clients may produce high absolute force but lower force relative to body weight.
This may matter for tasks such as:
walking
running
stair climbing
stepping
uneven-ground walking
change of direction
Body-weight percentage may help contextualise force relative to the body being moved, but it should be interpreted with function, symptoms and goals.
Reliability describes how consistent the test is when repeated. Validity describes whether the test measures what it is intended to measure. SEM estimates measurement error around a score. MDC estimates how much change may be needed to exceed measurement error.
A 2016 study directly examined foot inversion and eversion strength using handheld dynamometry in healthy adults. It assessed reliability, comparability and validity across sitting, supine and side-lying positions and compared handheld dynamometry with isokinetic dynamometry. The study found that test position and stabilisation influenced the results, which supports the need for a fixed and well-documented protocol.
Foot and ankle handheld dynamometry research in young and older adults found that HHD can be used reliably when protocols are standardised, but age-related strength differences and population context matter.
A 2025 systematic review on dynamometric ankle muscle strength reliability reported that reliability varies across procedures, equipment and testing methods, reinforcing the need for consistent device placement, stabilisation and protocol matching.
For the exact Measurz Muscle Meter ankle inversion protocol, high-quality peer-reviewed evidence reporting SEM, MDC, typical error or coefficient of variation appears limited unless the device, position and stabilisation match a published protocol.
Practical reliability guidance:
use the same device
use the same attachment
use the same joint angle
stabilise the lower leg
prevent whole-leg rotation
use consistent instructions
record pain and symptoms
repeat the same number of trials
avoid comparing different setups
treat small changes cautiously
A change is more meaningful when:
it exceeds known measurement error for a matching protocol
it is repeated across sessions
it aligns with improved function
symptoms are stable or improved
effort quality is consistent
the same device and setup were used
Common errors include:
not recording the test position
changing the ankle angle at retest
placing the device inconsistently
allowing whole-leg rotation
allowing toe flexion to dominate
not stabilising the lower leg
using different devices across sessions
mixing kg, lb and N without conversion
not recording pain during the test
using best trial at one session and average trial at another
treating the score as a diagnosis
using symmetry as the only readiness marker
Limitations include:
assessor strength can affect handheld push tests
device placement affects results
ankle angle affects force output
pain and apprehension can reduce effort
fatigue can reduce later trials
normative data are protocol-specific
% body weight values are not universal
the test measures force in one position, not full movement performance
The Ankle Inversion Muscle Meter test may help with:
baseline ankle strength testing
monitoring inversion strength over time
left-right comparison
ankle sprain progress tracking
medial ankle and foot strength monitoring
balance and foot-control context
sport performance support
workplace task assessment
client education
It is most useful when combined with:
ankle inversion range of motion
ankle eversion strength
ankle dorsiflexion strength
plantarflexion strength
calf raise testing
balance testing
gait observation
hop or jump testing where appropriate
pain and symptom notes
workload or training history
Record:
test name: Ankle Inversion Strength Test
muscle group or movement: ankle inversion
test type: push test, pull test, make test, strap-stabilised or handheld
device used: Muscle Meter, handheld dynamometer or other
attachment used: flat pad, strap, foot plate or other
side tested: left or right
dominance if relevant
score/result
units: kg, lb, N, kgf, lbf or %BW
body mass if calculating body-weight percentage
trial number
best score or average score
client position: seated, long-sitting or other
knee angle
ankle angle
device placement landmark
stabilisation method
force direction
contraction duration
client instructions
pain score
symptom location
symptoms during testing
compensations:
whole-leg rotation
toe flexion
ankle plantarflexion
knee movement
hip movement
trunk movement
effort quality
confidence
invalid trials
comparison side
baseline comparison
retest date
related findings:
ankle ROM
gait
balance
calf raise
dorsiflexion strength
eversion strength
toe strength
notes on interpretation
referral or further assessment notes if appropriate
Recording these details improves:
repeatability
communication
client education
assessment reasoning
monitoring over time
team consistency
reporting quality
It measures isometric force output during ankle inversion, usually by having the client push the inside of the foot into a Muscle Meter or handheld dynamometer.
The common Muscle Meter version is a push test or make test. The client pushes inward into a stationary device. Strap-stabilised or pull-style setups may also be used, but they should be recorded separately.
The test mainly assesses the ankle invertors, including tibialis posterior and tibialis anterior, with contribution from other medial foot and ankle muscles.
A lower score may suggest reduced force output in that position, but it does not explain why. Pain, fatigue, guarding, poor familiarisation, symptoms or poor setup may all influence the result.
Either can be used if recorded consistently. Many professionals record the best of 2–3 trials, while others use the average. Do not switch methods between baseline and retest.
If the device displays kilograms, divide force in kg by body mass in kg and multiply by 100. For example, 20 kg ÷ 80 kg × 100 = 25% body weight.
No. It may show reduced inversion force, but it does not diagnose the cause. It should be interpreted with symptoms, history, ankle ROM, balance, gait and related findings.
No. It can support strength monitoring, but return-to-sport reasoning should also consider symptoms, range of motion, balance, hopping, running, cutting, workload, fatigue, confidence and professional judgement.
The Ankle Inversion Strength Test measures isometric inversion force.
The common Muscle Meter version is a push or make test.
Record the exact device, attachment, position, ankle angle and units.
Higher scores may suggest greater force output in the tested position.
Lower scores may reflect strength limitation, pain, fatigue, guarding or test unfamiliarity.
Body-weight percentage can help compare force relative to body size but is not a universal pass/fail value.
Reliability depends on consistent setup, stabilisation, device placement and instructions.
Measurz should record score, units, side, trials, pain, symptoms, compensations, body mass, comparison side and retest conditions.
Alfuth, M., & Hahm, M. M. (2016). Reliability, comparability, and validity of foot inversion and eversion strength measurements using a hand-held dynamometer. International Journal of Sports Physical Therapy, 11(1), 72–84. PMID: 26900502. https://pmc.ncbi.nlm.nih.gov/articles/PMC4739050/
Chamorro, C., Armijo-Olivo, S., De la Fuente, C., Fuentes, J., & Chirosa, L. J. (2017). Absolute reliability and concurrent validity of hand-held dynamometry and isokinetic dynamometry in the hip, knee and ankle joint: Systematic review and meta-analysis. Open Medicine, 12, 359–375. https://doi.org/10.1515/med-2017-0052
Menz, H. B., Morris, M. E., & Lord, S. R. (2010). Foot and ankle strength, range of motion, posture, and deformity are associated with balance and functional ability in older people. Archives of Physical Medicine and Rehabilitation, 91(1), 68–75. https://doi.org/10.1016/j.apmr.2009.09.024
Mentiplay, B. F., Perraton, L. G., Bower, K. J., Pua, Y. H., McGaw, R., Heywood, S., & 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. https://doi.org/10.1371/journal.pone.0140822
Spink, M. J., Fotoohabadi, M. R., & Menz, H. B. (2010). Foot and ankle strength assessment using hand-held dynamometry: Reliability and age-related differences. Gerontology, 56(6), 525–532. https://doi.org/10.1159/000264655
van der Kruk, E., Reijne, M. M., & others. (2025). Measurement of maximal voluntary isometric lower limb muscle strength using a hand-held dynamometer in a non-injured healthy population: A systematic review of reference values, protocols, and sex differences. Physical Therapy in Sport. https://doi.org/10.1016/j.ptsp.2025.07.001
