Anker: Wrist Flexion Strength Test

The Wrist Flexion Strength Test measures the maximum isometric force produced when bending the wrist so the palm moves towards the forearm. Using the Anker, the assessment provides an objective and repeatable measure of wrist flexor strength in a standardised position.

Wrist flexion strength is essential for gripping, lifting, carrying, climbing, manual handling and many sporting movements including golf, tennis, baseball, cricket and gymnastics. Strong wrist flexors also contribute to grip stability by maintaining wrist position during forceful hand activities.

The primary muscles assessed include flexor carpi radialis, flexor carpi ulnaris and palmaris longus, with assistance from the finger flexors depending on hand position.

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 force only and should always be interpreted alongside symptoms, wrist mobility, grip strength and functional performance.

What Is the Wrist Flexion Strength Test?

The Wrist Flexion Strength Test is an isometric assessment where the client attempts to bend the wrist towards the palm while maintaining a stable forearm and elbow.

The assessment is commonly performed with the elbow flexed to approximately 90°, the forearm supported and the wrist beginning in a neutral position. Maintaining the same testing position improves repeatability between assessments.

The fixed resistance of the Anker allows objective strength measurement when client positioning, anatomical landmarks and instructions remain consistent.

Step-by-Step Protocol

1. Prepare the client

Explain that the assessment measures how strongly they can bend their wrist without moving the elbow or forearm.

Record any:

• wrist pain

• forearm pain

• hand pain

• previous wrist injury

• previous surgery

• neurological symptoms

• fatigue

Perform one or two familiarisation contractions before maximal testing.

2. Position the client

Position the client:

• seated upright

• forearm fully supported

• elbow flexed to approximately 90°

• forearm supinated

• wrist in neutral

• fingers relaxed

Maintain identical positioning during every reassessment.

3. Position the testing limb

Ensure:

• the forearm remains supported

• the elbow remains still

• the wrist begins in neutral

• the hand remains relaxed

Position the Anker load cell against the palmar surface of the second and third metacarpals, immediately proximal to the metacarpal heads.

Avoid direct pressure over the fingers or wrist joint.

Record the contact point for future testing.

4. Stabilise the client

Prevent movement of:

• forearm

• elbow

• shoulder

• trunk

The movement should occur only as an isometric wrist flexion effort.

5. Testing instructions

Use consistent verbal cues.

"Bend your wrist upwards."

"Increase the pressure smoothly."

"Push as hard as you can."

"Hold."

"Keep breathing."

Use the same wording during every reassessment.

6. Record the assessment

Use:

• 1–2 familiarisation trials

• 2–3 maximal trials

• 3–5 second contractions

• 30–60 seconds rest between trials

Record either:

• the highest force value, or

• the average of the recorded trials

Maintain the same scoring method during future testing.

7. Repeat the trial if

• the forearm lifts

• the elbow moves

• the shoulder compensates

• the fingers grip excessively

• the wrist deviates

• the load cell slips

• pain limits maximal effort

• the client starts before instructed

Why It Is Used

The assessment may be useful for:

• establishing baseline wrist flexor strength

• comparing left and right limbs

• monitoring progress over time

• upper-limb strength profiling

• athlete performance assessment

• objective reporting using Measurz

• monitoring response to exercise

• client education

The assessment supports broader clinical reasoning and should not be used as a stand-alone diagnostic assessment.

What It Measures

The primary outcome is peak isometric wrist flexion 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:

• wrist range of motion

• tendon integrity

• grip endurance

• dexterity

• readiness for work or sport

Understanding the Result, Reference Values and What to Look For

Higher force values generally indicate greater wrist flexor strength.

Lower force values may reflect:

• pain

• fatigue

• previous injury

• reduced confidence

• inconsistent positioning

• movement compensation

Interpret results by considering:

• previous assessment results

• left versus right differences

• symptoms during testing

• grip strength

• occupational and sporting demands

Published Anker-specific normative values are currently unavailable.

Handheld dynamometry demonstrates good reliability for wrist flexion testing when forearm position, wrist position and lever arm are standardised. Because testing protocols differ between systems, comparing results with the client's own baseline and repeated assessments using the same protocol is generally more meaningful than comparison with external reference values.

A side-to-side difference of approximately 10% or greater may warrant further assessment when accompanied by symptoms or functional limitations.

Assessing Different Client Populations

Youth

Interpret relative to growth, coordination and sporting participation.

Adults

Useful for baseline assessment and monitoring progress.

Older adults

Interpret alongside grip strength, hand function and activities of daily living.

Athletes

Particularly useful for climbing, gymnastics, golf, racquet sports, baseball, cricket and strength athletes.

Clients with persistent symptoms

Interpret alongside pain, confidence and functional capacity rather than strength alone.

Common Errors and Limitations

Common errors include:

• forearm lifting

• elbow movement

• finger gripping

• wrist deviation

• inconsistent load cell placement

• inconsistent verbal cueing

Limitations include:

• results are position-specific

• pain may reduce maximal force production

• strength alone does not determine upper-limb function

• published Anker-specific normative values remain limited

Practical Applications

The assessment may be useful for:

• baseline assessment

• progress monitoring

• side-to-side comparison

• upper-limb performance profiling

• objective reporting using Measurz

• educating clients using measurable outcomes

FAQs

What does the Wrist Flexion Strength Test measure?

It measures maximal isometric wrist flexion strength.

Which muscles are primarily assessed?

Flexor carpi radialis, flexor carpi ulnaris and palmaris longus.

Which metric should be used routinely?

Peak force is the primary outcome measure.

Should both wrists be tested?

Yes. Bilateral testing allows meaningful comparison.

Can this assessment diagnose wrist pathology?

No. It measures muscle force only.

Key Takeaways

• Measures maximal isometric wrist flexion strength.

• Primarily assesses the wrist flexor muscles.

• Peak force is the primary routine outcome measure.

• Consistent positioning and metacarpal contact point improve repeatability.

• Measurz provides additional force-time metrics.

• Compare results with previous assessments and the opposite limb.

References

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.

Stark, T., Walker, B., Phillips, J. K., Fejer, R., & Beck, R. (2011). Hand-held dynamometry correlation with the gold standard isokinetic dynamometry: A systematic review. PM&R, 3(5), 472–479.

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.