The Shoulder Horizontal Adduction Strength Test measures the maximum isometric force produced as the arm moves across the body in the transverse plane. Using the Anker, the assessment provides an objective and repeatable measure of shoulder horizontal adduction strength in a standardised position.
Horizontal adduction strength contributes to pushing movements, tackling, throwing follow-through, racquet sports, swimming, pressing exercises and upper-limb force production. The assessment is useful for baseline strength profiling, side-to-side comparison and monitoring changes over time.
The primary muscles assessed include the pectoralis major, anterior deltoid and coracobrachialis, with assistance from the short head of biceps brachii 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, shoulder mobility and functional performance.
The Shoulder Horizontal Adduction Strength Test is an isometric assessment where the client attempts to move the arm across the chest while maintaining a stable shoulder and trunk.
The test is typically performed with the shoulder abducted to 90° and the elbow flexed to 90°, allowing force to be generated primarily through the horizontal adductors while minimising compensatory movement.
The fixed resistance provided by the Anker allows consistent testing when the same positioning, anatomical landmarks and instructions are reproduced during each assessment.
Explain that the assessment measures how strongly they can bring their arm across their body.
Record any:
shoulder pain
chest pain
previous shoulder injury
previous surgery
stiffness
neurological symptoms
fatigue
Complete one or two familiarisation trials before maximal testing.
Position the client:
seated upright
feet flat on the floor
trunk supported
shoulder abducted to 90°
elbow flexed to 90°
forearm in neutral rotation
Maintain identical positioning during every reassessment.
Ensure:
the scapula remains in a neutral position
the humerus is 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 placing the load cell directly over the elbow joint.
Record the contact point to improve repeatability.
Prevent movement of:
trunk
scapula
opposite shoulder
pelvis
The effort should come from shoulder horizontal adduction rather than trunk rotation.
Use consistent verbal instructions.
"Push your arm across your body."
"Increase the pressure smoothly."
"Push as hard as you can."
"Hold."
"Keep breathing."
Use:
1–2 familiarisation trials
2–3 maximal trials
3–5 second contractions
30–60 seconds rest
Record either:
highest force value, or
average of recorded trials
Use the same scoring method during reassessment.
the trunk rotates
the shoulder elevates
the elbow changes position
the scapula excessively protracts
the load cell slips
pain limits maximal effort
the client starts before instructed
The assessment may be useful for:
baseline shoulder strength assessment
side-to-side comparison
athlete profiling
monitoring strength over time
objective reporting using Measurz
monitoring response to exercise
client education
The assessment should not be used as a stand-alone diagnostic or return-to-sport assessment.
The primary outcome is peak isometric shoulder horizontal adduction force.
Additional Measurz metrics 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 stability
rotator cuff integrity
shoulder mobility
throwing mechanics
sporting performance
Higher force values generally indicate greater horizontal adduction strength.
Lower values may reflect:
pain
previous injury
fatigue
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.
Upper-limb dynamometry has demonstrated excellent reliability when joint position, stabilisation and lever arm are standardised. Baseline comparison and repeated testing using identical procedures are generally more meaningful than comparing absolute force values between different devices.
A side-to-side difference greater than approximately 10% may warrant further assessment when accompanied by symptoms or reduced function.
Youth
Interpret relative to growth, coordination and sporting participation.
Adults
Useful for baseline strength assessment and monitoring progress.
Older adults
Interpret alongside upper-limb function and activities of daily living.
Athletes
Useful for throwing, racquet sports, swimming, rugby, AFL, combat sports and strength athletes.
Clients with persistent symptoms
Interpret alongside pain, confidence and functional performance rather than strength alone.
Common errors include:
trunk rotation
shoulder elevation
elbow movement
inconsistent load cell placement
scapular compensation
inconsistent verbal cueing
Limitations include:
results are specific to the testing position
pain may reduce force production
strength alone does not determine shoulder function
published Anker-specific normative values remain limited
The assessment may be useful for:
baseline shoulder assessment
athlete monitoring
side-to-side comparison
progress tracking
Measurz reporting
client education
Maximal isometric shoulder horizontal adduction strength.
Pectoralis major, anterior deltoid and coracobrachialis.
Peak force.
Yes. Bilateral assessment provides meaningful comparison.
No. It measures muscle force only.
Measures maximal isometric shoulder horizontal adduction strength.
Primarily assesses the pectoralis major and anterior deltoid.
Peak force is the primary outcome measure.
Consistent positioning improves repeatability.
Measurz provides additional force-time metrics.
Compare with previous assessments and the opposite limb.
Bohannon, R. W. (1997). Archives of Physical Medicine and Rehabilitation, 78(1), 26–32.
Mentiplay, B. F., et al. (2015). PLOS ONE, 10(10), e0140822.
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.
