The Forearm Pronation Strength Test measures the maximum isometric force produced when the forearm rotates so the palm faces downward. Using the Anker, the assessment provides an objective and repeatable measure of forearm pronation strength in a standardised position.
Pronation strength contributes to gripping, manual handling, tool use, lifting, throwing, racquet sports, climbing and many occupational tasks requiring forearm control. Assessing pronation complements supination testing and provides a more complete profile of forearm rotational strength.
The primary muscles assessed are the pronator teres and pronator quadratus, with assistance from the flexor carpi radialis during stabilisation.
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, elbow and wrist mobility, grip strength and functional performance.
The Forearm Pronation Strength Test is an isometric assessment where the client attempts to rotate the forearm so the palm turns downward while maintaining a stable elbow and upper arm.
The assessment is commonly performed with the elbow flexed to 90° and the shoulder positioned against the trunk to minimise compensation and improve repeatability.
The Anker provides fixed resistance, allowing consistent testing when positioning, anatomical landmarks and instructions remain unchanged.
Explain that the assessment measures how strongly they can rotate their palm downwards without moving the elbow or shoulder.
Record any:
elbow pain
forearm pain
wrist pain
previous upper-limb injury
previous surgery
neurological symptoms
fatigue
Complete one or two familiarisation contractions before maximal testing.
Position the client:
seated upright
feet flat on the floor
trunk supported
shoulder adducted against the trunk
elbow flexed to 90°
forearm in neutral rotation
wrist neutral
Maintain the same positioning during every reassessment.
Ensure:
the upper arm remains against the trunk
the elbow stays flexed to 90°
the wrist remains neutral
the hand remains relaxed
Position the Anker load cell against the dorsal surface of the distal forearm, immediately proximal to the radial and ulnar styloid processes.
Avoid placing the load cell directly over the wrist joint.
Record the contact point for consistent retesting.
Prevent movement of:
trunk
shoulder
upper arm
elbow
The movement should occur only as an isometric forearm pronation effort.
Use consistent verbal cues.
"Turn your palm down."
"Increase the pressure smoothly."
"Push as hard as you can."
"Hold."
"Keep breathing."
Use identical instructions during every reassessment.
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 recorded trials
Maintain the same scoring method during future testing.
the elbow moves
the shoulder rotates
the trunk leans
the wrist flexes or extends
the load cell slips
pain limits maximal effort
the client starts before instructed
The assessment may be useful for:
establishing baseline forearm strength
comparing left and right limbs
monitoring changes over time
upper-limb strength profiling
athlete performance assessment
objective reporting using Measurz
monitoring response to exercise
client education
The assessment should support broader assessment reasoning and should not be used as a stand-alone diagnostic or clearance assessment.
The primary outcome is peak isometric forearm pronation 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:
elbow stability
tendon integrity
range of motion
hand dexterity
grip endurance
readiness for work or sport
Higher force values generally indicate greater forearm pronation strength.
Lower force values may reflect:
pain
fatigue
previous injury
reduced effort
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.
Forearm rotational dynamometry demonstrates good repeatability when elbow position, forearm position and stabilisation remain consistent. Because testing methods differ between devices, baseline comparison and repeated testing using identical protocols provide the most clinically useful information.
A side-to-side difference of approximately 10% or greater may warrant further assessment when accompanied by symptoms or reduced functional performance.
Youth
Interpret relative to growth, coordination and sporting participation.
Adults
Useful for baseline assessment and monitoring progress.
Older adults
Interpret alongside upper-limb function and daily activities.
Athletes
Particularly useful for racquet sports, climbing, baseball, cricket, golf and strength athletes.
Clients with persistent symptoms
Interpret alongside pain, confidence and functional performance rather than strength alone.
Common errors include:
shoulder rotation
elbow movement
wrist flexion or extension
excessive gripping
inconsistent load cell placement
inconsistent verbal cueing
Limitations include:
results are position-specific
pain may reduce maximal force production
muscle strength alone does not determine function
published Anker-specific normative values remain limited
The assessment may be useful for:
establishing baseline forearm strength
monitoring progress
side-to-side comparison
upper-limb performance profiling
objective reporting within Measurz
educating clients using measurable outcomes
It measures maximal isometric forearm pronation strength.
The pronator teres and pronator quadratus.
Peak force is the primary outcome measure.
Yes. Bilateral testing provides meaningful comparison.
No. It measures muscle force only and should always be interpreted alongside other assessment findings.
Measures maximal isometric forearm pronation strength.
Primarily assesses the pronator teres and pronator quadratus.
Peak force is the primary routine outcome measure.
Consistent positioning and forearm contact point improve repeatability.
Measurz provides additional force-time metrics.
Compare results with previous assessments and the opposite limb.
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.
