The Shoulder Adduction Strength Test measures the maximum isometric force produced as the arm is drawn towards the side of the body. Using the Anker, the assessment provides an objective and repeatable measure of shoulder adductor strength in a standardised position.
Shoulder adduction is an important movement during climbing, swimming, rowing, gymnastics, lifting, pulling and many occupational tasks requiring upper-limb force. The assessment is useful for baseline strength profiling, side-to-side comparison and monitoring changes over time.
The primary muscles assessed include the latissimus dorsi, pectoralis major, teres major and coracobrachialis, with assistance from the long head of the triceps brachii depending on shoulder 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, shoulder mobility and functional performance.
The Shoulder Adduction Strength Test is an isometric assessment where the client attempts to pull the arm towards the body while maintaining a stable shoulder girdle and trunk.
The assessment is commonly performed with the shoulder abducted to approximately 90° and the elbow extended or comfortably flexed, depending on the Anker configuration. The objective is to isolate shoulder adduction while minimising compensation from the trunk or scapula.
The fixed resistance provided by the Anker allows consistent testing when the same client position, anatomical landmarks and verbal instructions are reproduced at every assessment.
Explain that the assessment measures how strongly they can pull their arm down towards their side.
Record any:
shoulder pain
upper arm pain
neck pain
previous shoulder injury
previous surgery
neurological symptoms
fatigue
Perform one or two submaximal familiarisation contractions before maximal testing.
Position the client:
seated upright
feet flat on the floor
trunk supported
shoulder abducted to approximately 90°
elbow comfortably extended or slightly flexed
forearm in neutral rotation
Maintain identical positioning during every reassessment.
Ensure:
the scapula remains neutral
the humerus remains level with the shoulder
the elbow remains aligned with the shoulder
the wrist remains relaxed
Position the Anker load cell against the medial aspect of the distal humerus, approximately 5 cm proximal to the medial epicondyle.
Avoid direct contact over the elbow joint.
Record the contact point to improve repeatability.
Prevent movement of:
trunk
pelvis
opposite shoulder
scapular elevation
The effort should occur through shoulder adduction rather than trunk side flexion or rotation.
Use consistent verbal instructions.
"Pull your arm towards your side."
"Increase the pressure smoothly."
"Push as hard as you can."
"Hold."
"Keep breathing."
Use the same 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 the recorded trials
Maintain the same scoring method during future assessments.
the trunk leans
the trunk rotates
the shoulder elevates
the elbow changes position
the load cell slips
pain limits maximal effort
the client starts before instructed
The assessment may be useful for:
establishing baseline shoulder strength
comparing left and right limbs
monitoring changes over time
athlete performance profiling
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 return-to-sport assessment.
The primary outcome is peak isometric shoulder adduction 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:
shoulder mobility
rotator cuff integrity
shoulder stability
movement quality
sporting performance
readiness for work or sport
Higher force values generally indicate greater shoulder adduction strength.
Lower force values may reflect:
pain
fatigue
previous injury
reduced effort
inconsistent positioning
movement compensation
Interpret results by considering:
previous assessments
left versus right comparison
symptoms during testing
movement compensations
functional demands
Published Anker-specific normative values are currently unavailable.
Shoulder dynamometry studies demonstrate excellent repeatability when testing position, stabilisation and lever arm remain consistent. Because force values vary between testing systems, comparison with the client's own baseline and repeated assessments using the same protocol are generally more meaningful than comparison with published values.
A side-to-side difference of approximately 10% or greater may warrant further assessment when accompanied by symptoms or functional limitations.
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 swimmers, climbers, rowers, gymnasts, rugby players and strength athletes.
Clients with persistent symptoms
Interpret alongside pain, confidence and functional performance rather than strength alone.
Common errors include:
trunk leaning
trunk rotation
shoulder elevation
elbow movement
inconsistent load cell placement
inconsistent verbal cueing
Limitations include:
results are position-specific
pain may reduce maximal force production
strength alone does not determine function
published Anker-specific normative values remain limited
The assessment may be useful for:
baseline shoulder assessment
monitoring progress
side-to-side comparison
athlete profiling
objective reporting within Measurz
educating clients using measurable outcomes
It measures maximal isometric shoulder adduction strength.
Latissimus dorsi, pectoralis major, teres major and coracobrachialis.
Peak force is the primary outcome measure.
Yes. Bilateral testing allows meaningful side-to-side comparison.
No. It measures muscle force only and should be interpreted alongside other assessment findings.
Measures maximal isometric shoulder adduction strength.
Primarily assesses the latissimus dorsi, pectoralis major and teres major.
Peak force is the primary routine outcome measure.
Consistent positioning and load cell placement improve repeatability.
Measurz provides additional force-time metrics.
Compare results with previous assessments and the opposite shoulder.
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.
