Arm length is an anthropometric measurement used to record the length of the upper limb or a defined upper-limb segment. It can be useful in health, fitness, sport, workplace, rehabilitation and performance settings because it provides context for reach, body proportions, equipment setup, upper-limb testing and some sport or work tasks.
Arm length can be measured in different ways depending on the purpose. Some protocols measure upper arm length, such as acromion to olecranon. Others measure full upper-limb length, such as acromion to fingertip. Because different methods produce different values, the method must be recorded clearly.
In Measurz, arm length can be useful when reviewed alongside arm span, hand span, forearm girth, arm girth, grip strength, pinch strength, shoulder range of motion, elbow range of motion and sport or work-specific tasks.
Arm length should not be interpreted as a performance score by itself. A longer arm may provide reach advantages in some activities, but performance also depends on strength, control, mobility, coordination, skill and task demands.
Arm length measurement records the distance between defined upper-limb landmarks.
Common methods include:
Upper arm length: acromion to olecranon
Full arm length: acromion to middle fingertip
Segmental arm length: upper arm, forearm or hand measured separately
Protocol-specific arm length: based on the assessment system being used
For Measurz, the most practical method should match the purpose of the test.
If the goal is to record upper-arm segment length for body measurement profiling, the acromion-to-olecranon method is useful.
If the goal is to record reach-related upper-limb length, acromion-to-middle-fingertip may be more useful.
The key is to record the exact landmarks used and repeat the same method each time.
Arm length measurement may be used to:
Record upper-limb body proportions
Add context to arm span
Add context to hand span
Support reach-based sport or workplace assessment
Support equipment setup
Support upper-limb profiling
Compare left and right upper-limb length
Add context to strength, grip or functional testing
Support growth and development tracking where appropriate
Create more complete Measurz body measurement records
Arm length is most useful when interpreted with other measurements and performance data. For example, reach-based tasks may be influenced by arm length, but they are also influenced by shoulder mobility, trunk position, strength, coordination and skill.
Arm length measures the distance between selected upper-limb landmarks.
It may provide useful information about:
Upper-limb segment length
Reach context
Body proportions
Side-to-side comparison
Equipment setup
Relationship to arm span and hand span
Sport or work task context
Growth and development context where appropriate
It does not directly measure:
Strength
Power
Mobility
Coordination
Pain source
Injury status
Joint health
Grip strength
Functional capacity
Readiness for sport or work
Performance ability
Arm length is best interpreted as a body measurement, not as a stand-alone functional test.
To measure arm length in Measurz, you will need:
Flexible non-elastic measuring tape or anthropometry tape
Optional anthropometer or segmental measuring device
Measurz app
Clear anatomical landmarks
Optional skin-safe marker
Notes field for side, landmarks and position
A non-elastic tape is recommended because stretchy tapes can affect repeatability.
Explain the purpose of the measurement clearly.
A useful explanation is:
“We are going to measure your arm length so we can record your upper-limb profile and compare it with other measurements such as arm span, hand span and strength results.”
Ask the client to remove bulky clothing that blocks landmarks.
Before testing, record:
Side tested
Measurement method
Landmarks used
Arm position
Any shoulder, elbow, wrist or hand limitation
Any reason the result may not compare directly with previous sessions
Choose the method that matches the assessment purpose.
Common options include:
Upper arm length
Measured from the acromion at the shoulder to the olecranon at the elbow.
Full arm length
Measured from the acromion at the shoulder to the tip of the middle finger.
Segmental arm length
Measured in separate sections, such as upper arm, forearm and hand.
Record the method clearly in Measurz.
Use a consistent position.
For upper arm length:
Client may sit or stand upright
Shoulder relaxed
Arm hanging naturally by the side
Elbow relaxed or positioned according to your protocol
For full arm length:
Client may stand or sit upright
Arm relaxed by the side or extended depending on protocol
Elbow straight if measuring to fingertip
Wrist and fingers positioned consistently
The same position should be used at retest.
For upper arm length, identify:
Acromion: bony point at the top/outside of the shoulder
Olecranon: bony point of the elbow
For full arm length, identify:
Acromion
Tip of the middle finger
If appropriate, mark the landmarks with a skin-safe marker.
Place the zero end of the tape at the starting landmark.
Run the tape in a straight line to the end landmark.
Check that the tape is:
Straight
Not twisted
Not following an unnecessary curve
Lightly tensioned
Aligned with the intended segment
Record the result in centimetres.
If side-to-side comparison is needed, repeat the same method on the opposite arm.
Use the same landmarks, same position and same tape path.
For improved confidence, take two measurements.
If values differ more than expected, recheck the landmarks and repeat.
A practical approach is to record the average of two close measurements.
Enter the result into Measurz with clear notes.
Useful notes include:
Right or left arm
Arm length value
Measurement unit
Upper arm length or full arm length
Landmarks used
Arm position
Number of trials
Any movement or positioning limitation
Any reason the result may not compare directly with previous sessions
The main score is arm length, usually recorded in centimetres.
Interpretation should consider:
Measurement method
Landmarks used
Right-left comparison
Relationship to arm span
Relationship to hand span
Shoulder, elbow and wrist position
Body height and proportions
Sport or work demands
Upper-limb strength results
Grip and pinch strength results
Range of motion results
Functional assessment findings
A longer arm may provide a reach advantage in some activities, but it does not automatically mean better performance. A shorter arm does not automatically mean poorer performance.
Arm length should be interpreted as a body proportion measure and reviewed alongside other Measurz data.
There are no simple universal “good” or “bad” arm length norms.
Arm length varies by height, age, sex, body proportions, population background and the exact landmarks used.
Large anthropometric datasets can provide reference values for specific populations, such as military, ergonomic or national survey samples. These values are useful only when the measurement method and population are relevant.
For most Measurz users, the most useful comparisons are:
The client’s own recorded value
Right-left comparison
Arm length compared with arm span and hand span
Arm length in relation to sport, work or equipment demands
Arm length alongside upper-limb strength, mobility and function
Use arm length as a profile measurement, not as a pass/fail score.
Arm length can be reliable when measured with a consistent method.
Reliability improves when:
The same landmarks are used
The same side is measured
The same arm position is used
The same tape or measuring device is used
The same tape path is used
The same number of trials is taken
Notes are recorded clearly in Measurz
Arm length is valid as a body segment measurement when the landmarks are identified correctly. It is not a direct measure of strength, mobility, function, injury status or performance.
Common errors include:
Not recording the landmarks used
Mixing upper arm length and full arm length
Measuring to the wrist in one session and fingertip in another
Letting the tape curve unnecessarily
Measuring with the elbow bent when it should be straight
Not recording side
Not recording arm position
Measuring over bulky clothing
Treating arm length as a performance score
Limitations include:
Landmarking can be difficult
Different methods produce different values
Arm length does not measure strength
Arm length does not measure mobility
Arm length does not measure coordination
It does not diagnose injury or explain symptoms
It should not be used alone for sport or work decisions
Arm length may be useful for:
Upper-limb profiling
Arm span and reach context
Hand span comparison
Equipment setup
Sport-specific profiling
Workplace task setup
Grip and reach-related assessment context
Growth and development tracking where appropriate
Measurz body measurement reports
For example, arm length may provide context in sports or tasks where reach matters, but performance still depends on mobility, strength, timing, skill and control.
When recording arm length in Measurz, include:
Client name
Test date
Right or left arm
Arm length value
Measurement unit
Upper arm length or full arm length method
Landmarks used
Arm position
Number of trials
Any shoulder, elbow, wrist or hand limitation
Any reason the result may not compare directly with previous sessions
For best results, use the same landmarks, same side and same arm position each time.
Measurz can help organise arm length alongside arm span, hand span, forearm girth, arm girth, grip strength, pinch strength, shoulder range of motion and other upper-limb results.
Arm length is the distance between selected upper-limb landmarks, such as the shoulder to the elbow or shoulder to the fingertip.
The best method depends on the purpose. Upper arm length often uses acromion to olecranon. Full arm length may use acromion to the middle fingertip.
Yes, if side-to-side comparison is relevant.
No. Arm span measures fingertip-to-fingertip distance across both arms. Arm length measures one arm or one upper-limb segment.
No. Arm length varies widely and depends on the exact method used.
No. Arm length is a body measurement, not a performance test.
Yes. It may provide useful context for reach, grip position and equipment fit.
No. It should be interpreted alongside other Measurz assessment findings.
Arm length measures a defined upper-limb distance.
The exact landmarks must be recorded clearly.
Upper arm length and full arm length are different measurements.
There are no simple universal “good” or “bad” arm length norms.
Arm length may provide useful context for reach, equipment setup and sport or work demands.
Arm length does not directly measure strength, mobility, injury status or performance.
It should be interpreted alongside other Measurz assessment findings.
Gordon, C. C., Blackwell, C. L., Bradtmiller, B., Parham, J. L., Barrientos, P., Paquette, S. P., Corner, B. D., Carson, J. M., Venezia, J. C., Rockwell, B. M., Mucher, M., & Kristensen, S. (2014). 2012 Anthropometric Survey of U.S. Army Personnel: Methods and summary statistics. U.S. Army Natick Soldier Research, Development and Engineering Center.
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Marfell-Jones, M., Stewart, A., & de Ridder, H. (2012). International standards for anthropometric assessment. International Society for the Advancement of Kinanthropometry.
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