The Neck Lateral Flexion Strength Test measures how much force a client can produce when bending the head and neck sideways against resistance. It is commonly used to assess cervical side-flexion force output in a controlled isometric setup.

Neck lateral flexion strength can provide useful context for direction-to-direction neck strength profiling, contact sport, collision sport, helmeted sport, posture tolerance, occupational head and neck demands, progress tracking and comparison between right and left sides. The main contributors include the cervical lateral flexors, upper trapezius region, scalenes, sternocleidomastoid contribution and deeper stabilising muscles, although head position, shoulder position, trunk stabilisation and client confidence can all influence the result.

The Muscle Meter is a handheld dynamometry tool used to measure force output during push, pull and isometric strength assessments. When used on its own, the Muscle Meter primarily measures peak force, which is the highest force value produced during the test. When used with Measurz, Muscle Meter data can be recorded and analysed with a broader set of strength and force-time metrics, including peak force, impulse, torque, rate of torque development, rate of force development, time to peak and fatigue index.

For routine neck lateral flexion testing, peak force is usually the main metric. Force as a percentage of body weight may be useful if directly calculated from the client’s test force and body weight, but cervical strength is usually more meaningful when compared with the client’s own baseline, side-to-side profile, direction-to-direction profile and a matched protocol. Rate of force development and time to peak may be useful when rapid neck force production matters, such as contact sport, collision sport or high-speed sport contexts. Impulse may be useful if sustained force over a defined time window is intentionally tested. Fatigue index is only relevant if repeated or sustained lateral flexion efforts are part of the protocol.

The result can support assessment reasoning and progress tracking, but it does not diagnose neck pain, cervical pathology, nerve involvement, headache source, whiplash status, concussion risk or readiness for sport or work on its own.

What Is the Neck Lateral Flexion Strength Test?

The Neck Lateral Flexion Strength Test is an isometric cervical strength assessment where the client attempts to bend the head and neck sideways into the Muscle Meter, strap or fixed setup without visible movement. The device is usually placed against the side of the head, commonly near the temporal region or into a head strap positioned to capture side-bending force.

The movement direction is cervical lateral flexion. The purpose of the test is to measure how much side-bending head and neck force the client can produce in a specific position.

Consistent setup matters because body position, head position, neck angle, device placement, strap position, trunk stabilisation, shoulder position, jaw position, client effort and symptom response can all affect the result. This test measures force output in a specific setup. It does not fully measure neck endurance, motor control, pain source, cervical joint status, sport contact tolerance, concussion risk or work readiness on its own.

Step-by-Step Protocol / Practice

1. Prepare the client

Explain that the test measures how strongly they can push the head and neck sideways into the Muscle Meter. Record baseline neck symptoms, headache, dizziness, visual symptoms, jaw discomfort, shoulder symptoms, arm symptoms, paraesthesia, fatigue, recent contact exposure, recent training load and confidence with maximal effort.

Use at least one submaximal practice trial on each side so the client understands the force direction and how to build force smoothly without shoulder shrugging, jaw clenching, breath holding or trunk compensation.

2. Set the client position

Neck lateral flexion can be tested seated, standing or side-lying depending on the protocol and available setup. Seated or standing testing is practical but requires careful trunk and shoulder stabilisation. Side-lying or strap-stabilised testing may improve control in some settings.

Record:

• Seated, standing, side-lying or other position
• Test side
• Head and neck start position
• Cervical angle
• Trunk position
• Shoulder position
• Jaw position if relevant
• Device contact point
• Strap or head harness position if used
• Whether the trunk was stabilised
• Whether symptoms were present before testing

The head and neck should start in a neutral position unless another position is intentionally chosen. The shoulders should stay level and relaxed.

3. Set up the device or straps

For a handheld setup, the professional holds the Muscle Meter against the side of the head while the client pushes sideways into it. For stronger clients or improved repeatability, a strap-stabilised or fixed setup may be used.

If using a strap or head harness, record:

• Strap or harness position
• Anchor point
• Strap angle
• Strap length
• Device position
• Whether any pre-tension was used
• Whether the anchor or strap moved during testing

Handheld, strap-stabilised, head harness and fixed-frame scores should be recorded separately unless the protocol supports direct comparison.

4. Place the device, strap or handle

Place the Muscle Meter against the side of the head, commonly near the temporal region or into the head strap/harness contact point, depending on the chosen protocol. Avoid uncomfortable pressure around the ear, jaw, eye, cheekbone or sensitive structures.

The force direction should be cervical lateral flexion. The client should push the head and neck sideways into the device without shrugging, rotating the head, leaning the trunk or clenching the jaw excessively.

5. Stabilise the position

Stabilise the trunk and shoulders so the client does not compensate with trunk side-bending, shoulder shrugging, shoulder elevation, head rotation, jaw clenching or whole-body effort.

The aim is controlled cervical lateral flexion force in the chosen position.

6. Give clear instructions

Use consistent instructions such as:

“Push the side of your head into the device as hard as you can and hold.”
“Build up smoothly, then push hard.”
“Keep your shoulders and body still.”
“Do not rotate your head.”
“Keep your jaw relaxed where possible.”
“Keep breathing.”
“Tell me if you feel neck pain, headache, dizziness, tingling, visual symptoms or anything unusual.”

Use the same wording at retest where possible.

7. Record trials

Use 1–2 practice trials per side, then record 2–3 maximal trials per side. A common contraction duration is 3 seconds, although 3–5 seconds may be used if it is recorded and repeated consistently. Rest for 30–60 seconds between trials, or longer if symptoms, dizziness, headache, fatigue or apprehension occur.

Record whether the final score uses the best trial or the average of recorded trials. Either approach may be used if it is applied consistently. Record side order and repeat it at retest where possible.

8. Identify invalid trials

Repeat or mark a trial as invalid if:

• The trunk side-bends or rotates
• The shoulder lifts or shrugs
• The head rotates instead of side-bending
• The head position changes before the effort
• The jaw clenches strongly or changes the setup
• The device slips
• The strap or anchor moves
• The client pushes with the body instead of the neck
• Pain, headache, dizziness or neurological symptoms limit effort
• The client starts before the device is ready
• The client holds their breath excessively
• The professional cannot hold the device steady

9. Record symptoms

Record neck pain, headache, dizziness, visual symptoms, jaw symptoms, shoulder symptoms, arm symptoms, paraesthesia, confidence, apprehension and symptom response after testing. Do not repeatedly test through worsening symptoms, significant dizziness, neurological symptoms or high pain.

For retesting, match the same body position, side order, head position, device placement, strap setup, instructions, contraction duration, rest period, scoring method and symptom recording.

Why It Is Used

The Neck Lateral Flexion Strength Test is used to quantify cervical side-bending force output in a repeatable setup. It may be useful for:

• Baseline neck strength assessment
• Monitoring change over time
• Right-to-left comparison
• Comparing lateral flexion with flexion and extension
• Supporting contact sport and collision sport strength profiling
• Supporting helmeted sport or occupational head-load assessment reasoning
• Tracking symptom response to resisted cervical side-bending
• General neck strength profiling
• Client education
• Fitness and performance progress tracking

The test should support assessment reasoning. It should not be used as a stand-alone diagnostic, concussion-risk or clearance measure.

What It Measures

The test primarily measures isometric cervical lateral flexion force output in the chosen setup. It reflects the client’s ability to produce side-bending head and neck force while controlling trunk and shoulder position.

It may provide useful information about:

• Cervical lateral flexion force capacity
• Right-to-left force difference
• Direction-to-direction comparison
• Force relative to body weight, if calculated
• Confidence producing neck force
• Symptom response during resisted lateral flexion
• Change in force over time
• Relationship between neck strength and related sport, work or daily-life tasks

It does not directly measure:

• Cause of neck pain
• Headache source
• Cervical joint status
• Nerve function
• Concussion risk
• Whiplash status
• Neck endurance
• Sport contact readiness
• Work readiness

Understanding the Result, Reference Values and What to Look For

What a higher or lower result may suggest

A higher score may suggest greater cervical lateral flexion force output in that specific setup. A lower score may suggest reduced side-bending force output, but the reason should be interpreted carefully.

Lower force may be influenced by pain, apprehension, poor familiarisation, fatigue, guarding, inconsistent device placement, poor trunk stabilisation, shoulder shrugging, jaw clenching, headache, dizziness, reduced confidence or fear of symptoms.

One result should not be interpreted in isolation. Interpretation is strongest when the same setup is repeated over time and reviewed alongside symptoms, confidence, neck range of motion, neck flexion strength, neck extension strength, opposite-side lateral flexion strength, endurance, sport demands, work demands and functional goals.

What can influence the result

Important influences include:

• Neck pain
• Headache
• Dizziness or vestibular symptoms
• Apprehension
• Poor familiarisation
• Fatigue
• Guarding
• Head and neck angle
• Head rotation
• Trunk stabilisation
• Shoulder position
• Shoulder shrugging
• Jaw clenching
• Device placement
• Strap angle
• Breath holding
• Client confidence
• Professional strength if using handheld resistance

Normative, reference and comparative values

Published Muscle Meter-specific universal norms for neck lateral flexion are limited. Reference values should therefore be used as context only and not as direct targets unless the protocol is closely matched.

More user-friendly comparison data include:

• In healthy young adults tested with fixed-frame dynamometry, neck strength showed a broad range across directions, approximately 38–383 N in men and 15–223 N in women. These broad ranges show how much sex, body size, neck size and protocol can influence results.
• A study of healthy women using a specialised cervical strength setup reported average maximal isometric cervical strength values across directions and found that age and anthropometric variables can influence results. This supports matching comparison data by sex, age, body size and protocol wherever possible.
• Handheld dynamometry protocols for cervical strength have reported moderate-to-excellent reliability when trunk stabilisation, device placement and contraction duration are standardised. This supports using the same setup for retesting rather than relying on broad universal values.
• In one handheld dynamometry protocol, maximal contractions were sustained for 3 seconds, repeated 3 times, with 1 minute rest between repetitions and 3 minutes rest between movement directions. This is a useful practical template for repeatable testing.
• For side-to-side comparison, a difference of around 10% or more is often worth reviewing more closely, especially if it matches symptoms, previous injury, confidence changes, sport exposure or work demands. This should not be used as a strict pass/fail cut-off.
• For repeated testing, the client’s own baseline, repeatability and symptom response are usually more useful than broad population values.
• If force is recorded as a percentage of body weight in Measurz, use it mainly for internal comparison over time. Bodyweight percentage should not be treated as a universal neck lateral flexion target unless the comparison data use the same calculation and protocol.

These values and comparisons are best used as context. They can help structure interpretation, but they should not be used as diagnostic, concussion-risk, clearance or pass/fail cut-offs.

Practical interpretation priorities

Use this order:

1. Compare with the client’s own baseline.
2. Compare right and left lateral flexion.
3. Compare lateral flexion with flexion and extension where relevant.
4. Review force relative to body weight where calculated.
5. Consider symptoms during and after testing.
6. Consider confidence and effort quality.
7. Review whether compensations were present.
8. Compare with neck range of motion and endurance where relevant.
9. Relate the result to sport, work, posture or daily-life demands.
10. Retest under the same conditions to monitor change.
11. Do not use reference values as pass/fail criteria.

What to look at for each relevant Muscle Meter metric

Peak force
Use for maximum neck lateral flexion force output, baseline strength, side-to-side comparison, direction-to-direction comparison and progress tracking. Look for best score or average score, consistent setup, change from baseline, symptom response and whether compensations occurred.

Force as percentage of body weight
Use only when calculated directly from test force and body weight. It may help internal monitoring, but it should not be treated as a universal target unless the comparison data use the same protocol.

Torque
Use only when a lever arm is measured and a more biomechanical interpretation is needed. It should not be used as normative data unless the reference data match the setup closely.

Rate of force development
Use when rapid neck force production matters, such as contact sport, collision sport or high-speed sport contexts. Look for early force production and whether rate of force development changes while peak force stays similar.

Time to peak
Use to understand whether force is produced quickly or gradually. A slower time to peak may reflect caution, symptom concern, poor cueing or a true force-production difference.

Impulse
Use only if a defined sustained force window is intentionally tested. It may help when the aim is to understand force maintained over a brief contraction.

Fatigue index
Use only if repeated or sustained neck lateral flexion efforts are part of the protocol. Look for drop-off across repeated trials and whether the decline matches symptoms, fatigue or apprehension.

Assessing and Providing Context for Different Client Populations

Youth clients
Consider growth, maturity, confidence, attention, sport exposure and careful symptom screening. Use conservative familiarisation and avoid forcing maximal efforts if symptoms occur.

Adults and general fitness clients
Use the test for baseline neck strength, progress tracking and comparison with other neck directions. Compare results with posture tolerance, range of motion, endurance and symptoms.

Older adults
Consider comfort, dizziness, headache, balance, neck mobility, fatigue and confidence. Use gentler familiarisation and avoid repeated maximal efforts if symptoms are provoked.

Athletes and sport clients
Consider contact, collision, grappling, heading, motorsport, combat sport and high-speed sport demands. Neck strength can support profiling, but it should not be used alone to judge concussion risk or sport readiness.

Workplace and manual task clients
Consider helmets, head-mounted equipment, driving, machinery operation, prolonged postures, overhead work and repeated head movement. Do not use one score to clear work duties.

Clients returning after injury
Use the test to monitor force output, confidence and symptom response. Strength alone should not confirm readiness.

Clients with pain or persistent symptoms
Pain, headache, dizziness, fear, guarding, fatigue, apprehension and confidence may reduce force. Record symptom response carefully and compare with related tests.

Higher body mass clients
Absolute force and force relative to body mass may both be useful. Interpret results in relation to goals, symptoms, neck size and functional demands, not assumptions about body size.

Reliability, Validity and Measurement Considerations

Repeatability improves when the same setup is used each time. Record and standardise:

• Same body position
• Same side order
• Same head and neck position
• Same cervical angle
• Same trunk stabilisation
• Same shoulder position
• Same jaw instruction
• Same device placement
• Same strap or harness setup, if used
• Same anchor height and distance, if used
• Same contraction duration
• Same rest period
• Same instructions
• Same scoring method
• Same symptom and compensation recording

Neck strength testing is highly setup-dependent. Small changes in head position, device placement, trunk stabilisation or symptom response can change the score. For stronger clients, handheld resistance may be limited by professional strength. Strap-stabilised or fixed setups can improve repeatability.

Common Errors and Limitations

Common errors include:

• Trunk side-bending or rotating
• Shoulder shrugging
• Head rotation instead of lateral flexion
• Jaw clenching
• Device placement changing between trials
• Head position changing before the effort
• Breath holding
• Testing through worsening headache or dizziness
• Strap or anchor movement
• Poor familiarisation
• Comparing different protocols directly
• Treating the score as a diagnosis

Limitations include:

• Testing is setup-dependent
• Manual resistance may be limited by professional strength
• Muscle Meter-specific universal norms may be limited
• Published cervical strength values vary by device, posture and population
• Pain, headache, dizziness, fear or guarding can reduce force output
• Peak force does not measure endurance or motor control
• Strong force or symmetry does not automatically indicate readiness for contact sport or work

Practical Applications

The Neck Lateral Flexion Strength Test may be useful for:

• Baseline cervical strength assessment
• Monitoring response to exercise or intervention
• Right-to-left neck strength comparison
• Direction-to-direction neck strength profiling
• Contact sport and collision sport strength profiling
• Occupational neck strength profiling
• Comparing with neck flexion, extension, rotation, range of motion and endurance tests
• Client education
• Fitness and performance progress tracking

Ideas to Make the Result Better

If force is low on both sides, consider assessing neck flexion strength, neck extension strength, neck range of motion, endurance, posture tolerance, confidence, symptoms and familiarisation.

If one side is lower, compare with symptoms, side-specific sport or work demands, previous injury, cervical range of motion, shoulder symptoms and test setup.

If symptoms limit the result, record symptom location and type, review test position and compare with related findings rather than forcing repeated maximal trials.

If force improves but symptoms remain, consider reviewing endurance, range of motion, work/sport exposure, posture tolerance and recovery between sessions.

If the client is improving, keep the same test setup and monitor whether force, symptoms, confidence and function improve together.

Recommended Standard Protocol Summary

Position: Seated, standing, side-lying or chosen neck lateral flexion test position
Start position: Head and neck neutral unless otherwise specified
Joint or trunk angle: Record cervical, trunk and shoulder position
Trials: 1–2 practice trials, then 2–3 recorded trials per side
Contraction duration: Commonly 3 seconds, or 3–5 seconds if used consistently
Rest: 30–60 seconds between efforts; longer if symptoms occur
Metric: Peak force, side-to-side difference, plus percentage of body weight if directly calculated
Attachment or device setup: Muscle Meter against side of head or connected to a head strap/harness with consistent contact point
Final score: Best trial or average of trials
Key retesting requirement: Same body position, side order, head position, device placement, stabilisation, instructions, contraction duration, rest and scoring method

FAQs

What does the Neck Lateral Flexion Strength Test measure?

It measures isometric cervical side-bending force output in a specific setup.

Should both sides be tested?

Yes. Testing both sides allows right-to-left comparison, which is often more useful than interpreting one isolated value.

Should the result be recorded as percentage of body weight?

It can be if calculated directly from force and body weight, but neck lateral flexion is usually best interpreted using baseline comparison and a matched retest protocol.

Are there universal neck lateral flexion norms for the Muscle Meter?

Published universal Muscle Meter norms for this exact protocol appear limited. Broad cervical strength values exist, but they vary by device, position, sex, body size and protocol.

What numerical values are available for comparison?

Healthy young adult cervical strength ranges have been reported broadly across directions, including approximately 38–383 N in men and 15–223 N in women. These broad ranges show why matched protocols are more useful than universal targets.

Can this test diagnose neck pain or concussion risk?

No. It can measure force output and symptom response, but it does not diagnose a condition or determine concussion risk on its own.

What can make the result unreliable?

Changing head position, trunk movement, shoulder shrugging, jaw clenching, device slipping, pain, headache, dizziness, fatigue and inconsistent instructions can affect results.

What should be recorded in Measurz?

Record side, position, head and neck angle, device placement, peak force, symptoms, confidence, compensations, bodyweight-relative value if calculated, scoring method and related findings.

Key Takeaways

• The Neck Lateral Flexion Strength Test measures isometric cervical side-bending force output.
• Peak force is usually the main routine Muscle Meter metric.
• Right-to-left comparison is especially useful.
• Published cervical strength values vary substantially by device, body position, stabilisation, sex and body size.
• Percentage of body weight should only be used when calculated directly from force and body weight.
• Baseline comparison, symptom response and retesting consistency are more useful than broad norms.
• Measurz should capture side, setup, symptoms, force, confidence, compensations and retesting conditions.

References

Abichandani, D., Tong Yuk Ting, J., Elgueta Cancino, E., Althobaiti, S., & Falla, D. (2023). Measures of neck muscle strength and their measurement properties in adults with chronic neck pain: A systematic review. Systematic Reviews, 12, 6. https://doi.org/10.1186/s13643-022-02162-5

Catenaccio, E., Mu, W., Kaplan, A., Fleysher, R., Kim, N., Bachrach, T., Sears, M. Z., Jaspan, O., Caccese, J., Kim, M., Wagshul, M., Stewart, W. F., Lipton, R. B., & Lipton, M. L. (2017). Characterization of neck strength in healthy young adults. PM&R.

Gorla, C., Martins, T. de S., Florencio, L. L., Pinheiro-Araújo, C. F., Fernández-de-las-Peñas, C., Martins, J., & Bevilaqua-Grossi, D. (2023). Reference values for cervical muscle strength in healthy women using a hand-held dynamometer and the association with age and anthropometric variables. Healthcare, 11(16), 2278. https://doi.org/10.3390/healthcare11162278

Salo, P. K., Ylinen, J. J., Mälkiä, E. A., Kautiainen, H., & Häkkinen, A. H. (2006). Isometric strength of the cervical flexor, extensor, and rotator muscles in 220 healthy females aged 20 to 59 years. Journal of Orthopaedic & Sports Physical Therapy, 36(7), 495–502. https://doi.org/10.2519/jospt.2006.2122

Versteegh, T. H., Beaudet, D. A., Greenbaum, M., Hellyer, L., Tritton, A., & Walton, D. M. (2015). Evaluating the reliability of a novel neck-strength assessment protocol for healthy adults using self-generated resistance with a hand-held dynamometer. Physiotherapy Canada, 67(1), 58–64. https://doi.org/10.3138/ptc.2013-66