The Cervical Rotation Lateral Flexion Test is a neck and upper thoracic assessment commonly used to observe whether cervical rotation followed by lateral flexion is limited, uncomfortable or asymmetrical. It is often taught as a first rib mobility test and may be used when neck, shoulder girdle, upper-limb or thoracic outlet-type symptoms are being considered. A positive finding may include restricted movement, asymmetry, familiar symptom reproduction or altered end-feel. The test should not be used alone to confirm first rib dysfunction, thoracic outlet syndrome or a specific anatomical cause of symptoms.

Introduction

The Cervical Rotation Lateral Flexion Test, often abbreviated as the CRLF Test, is commonly used in the assessment of neck, shoulder girdle and upper-limb symptoms. It is often associated with first rib mobility assessment because the final lateral flexion component may be limited when the first rib or cervicothoracic region does not move as expected.

In practice, the test is usually performed by rotating the cervical spine away from the side being assessed, then laterally flexing the neck. The professional observes whether the movement is restricted, asymmetrical, uncomfortable or symptom-producing.

Although the test is widely taught, interpretation should be cautious. Neck and shoulder symptoms can be influenced by cervical joints, upper thoracic mobility, scalene sensitivity, neural mechanosensitivity, rib mobility, posture, muscle guarding and thoracic outlet-related presentations. A positive CRLF Test may support further assessment, but it does not confirm one structure or condition.

Quick Summary

Test name: Cervical Rotation Lateral Flexion Test
Also known as: CRLF Test, Cervical Rotation Lateral Flexion Test for First Rib Mobility
Body region: Cervical spine, first rib, cervicothoracic junction and shoulder girdle
Purpose: Assess movement restriction or symptom response during cervical rotation and lateral flexion
Commonly associated with: First rib mobility assessment, neck/shoulder symptoms and thoracic outlet reasoning
Positive finding: Restricted lateral flexion, asymmetry, altered end-feel or familiar symptom reproduction
Negative finding: Expected movement without meaningful restriction, asymmetry or familiar symptoms
Best used with: Cervical ROM, first rib palpation, upper-limb neurodynamic testing, Adson’s Test, Halstead Test, Eden Test, Roos Test and shoulder assessment
Key limitation: A positive test does not confirm first rib dysfunction or thoracic outlet syndrome.

What Is the Cervical Rotation Lateral Flexion Test?

The Cervical Rotation Lateral Flexion Test is a movement-based assessment of the cervical and upper thoracic region. The professional positions the client’s neck in rotation, then adds lateral flexion. The side being assessed depends on the protocol used, but the test is commonly interpreted in relation to first rib mobility and cervicothoracic movement.

A meaningful finding may include limited movement compared with the opposite side, reproduction of familiar neck or upper-limb symptoms, discomfort around the scalene or first rib region, or a firm or blocked end-feel. Because several structures can influence the test, the result should be recorded descriptively rather than used as a diagnosis.

Why It Is Used

The CRLF Test is used to assess whether cervical and upper thoracic movement is limited or symptom-provoking in a pattern that may be relevant to first rib, cervicothoracic or thoracic outlet assessment reasoning.

It may be useful when a client reports neck pain, shoulder girdle symptoms, upper-limb paraesthesia, symptoms influenced by overhead activity, or discomfort around the scalene and first rib region. The test may also help guide whether first rib palpation, cervical ROM, shoulder assessment or thoracic outlet provocation testing should be explored further.

What It Assesses

The Cervical Rotation Lateral Flexion Test assesses:

• Cervical rotation and lateral flexion movement quality
• Possible first rib or cervicothoracic movement restriction
• Side-to-side movement asymmetry
• Symptom response during combined cervical movement
• End-feel during lateral flexion
• Scalene, upper trapezius or upper thoracic sensitivity
• Whether movement findings fit the client’s neck, shoulder or upper-limb symptoms

It does not directly assess vascular compression, brachial plexus compression or a single anatomical structure.

Who It Is Useful For

This test may be useful for adults with neck pain, shoulder girdle symptoms, upper-limb symptoms, suspected first rib involvement, cervicothoracic stiffness or symptoms that appear influenced by posture, breathing, overhead activity or neck position.

It may also be useful for professionals learning to assess movement quality and symptom behaviour around the cervicothoracic region. It should be avoided or modified when cervical movement is not safe or tolerated.

When to Use This Test

Use the CRLF Test when:

• First rib or cervicothoracic movement is part of the assessment reasoning
• The client reports neck, shoulder girdle or upper-limb symptoms
• Cervical rotation and lateral flexion can be performed safely
• You want to compare sides
• You can monitor familiar symptom reproduction
• The result will guide further assessment rather than stand alone

When Not to Use or When to Be Cautious

Use caution or avoid the test when there is acute trauma, suspected cervical fracture, suspected cervical instability, inflammatory instability, severe osteoporosis risk, dizziness, vascular symptoms, neurological deterioration, unexplained severe headache, recent cervical surgery or symptoms requiring urgent medical review.

Stop the test if dizziness, nausea, visual symptoms, neurological symptoms, severe pain, sharp symptom increase, faintness or distress occurs.

Equipment Required

The Cervical Rotation Lateral Flexion Test requires minimal equipment:

• Chair or treatment table
• Pain and symptom rating scale
• Symptom-location recording method
• Optional inclinometer or cervical ROM device
• Measurz app for structured documentation
• Optional video for setup and movement review
• Optional MAT notes for cervical, shoulder and thoracic outlet findings

Within Measurz, this test can be recorded alongside cervical ROM, shoulder ROM, first rib palpation notes, upper-limb neurodynamic tests, Adson’s Test, Halstead Test, Eden Test, Roos Stress Test and neurological screening. Measurz features such as video recording, inclinometer measures and structured test notes can help improve repeatability and comparison across sessions.

Step-by-Step Protocol / Practice

Setup

Explain that the test checks how the neck and upper rib region move during combined rotation and side bending. Clarify baseline symptoms before testing, including neck pain, shoulder symptoms, upper-limb paraesthesia, heaviness or headache symptoms.

Client position

The client sits upright or lies supine depending on the protocol used. Sitting is common for simple movement observation, while supine may allow greater relaxation and examiner control.

Examiner/professional position

Stand or sit near the client so the head, neck and shoulder girdle can be supported and observed. Monitor symptoms and safety throughout.

Hand placement

Support the head and neck gently. If testing supine, one hand may guide cervical rotation while the other guides lateral flexion. Avoid compressing the jaw, throat or sensitive anterior neck tissues.

Stabilisation

The client should remain relaxed. The shoulder girdle should not be aggressively depressed unless a specific modified protocol is being used and documented.

Movement or force direction

A common sequence is:

1. Bring the cervical spine into rotation away from the side being assessed.
2. Add lateral flexion away from or toward the side depending on the protocol being used.
3. Compare range, symptom response and end-feel with the opposite side.
4. Record the side assessed, direction used and symptom response.

The movement should be slow and controlled. Do not force end range.

Instructions

Ask:

“Tell me if this produces neck, shoulder or arm symptoms.”
“Tell me if the symptom feels familiar.”
“Let me know if you feel dizziness, tingling, numbness or anything unusual.”
“Tell me if one side feels more restricted or uncomfortable than the other.”

Positive finding

A positive finding may include reduced movement, asymmetry compared with the other side, firm or blocked end-feel, familiar symptom reproduction, or discomfort around the first rib/scalene/cervicothoracic region.

Negative finding

A negative finding is expected movement without meaningful restriction, asymmetry, familiar symptom reproduction or concerning symptoms.

Stopping criteria

Stop if dizziness, nausea, visual disturbance, neurological symptoms, sharp pain, marked symptom worsening or client distress occurs.

Safety notes

Avoid aggressive end-range movement. Use extra caution when upper-limb neurological or vascular symptoms are present.

Positive and Negative Test Interpretation

A positive Cervical Rotation Lateral Flexion Test may suggest altered movement in the cervical, cervicothoracic or first rib region. It may support further assessment of the first rib, upper thoracic spine, scalene region, shoulder girdle, thoracic outlet symptoms or upper-limb neural sensitivity.

A positive test does not confirm first rib dysfunction, thoracic outlet syndrome, rib elevation or a specific tissue source. Movement restriction may be influenced by cervical joint stiffness, muscle guarding, neural sensitivity, shoulder girdle position, pain irritability or examiner technique.

A negative test means the tested movement did not show a meaningful restriction or familiar symptom response. This does not fully exclude first rib, cervical, shoulder or thoracic outlet involvement, especially if symptoms are provoked by other positions or activities.

Sensitivity, Specificity and Diagnostic Accuracy

At the time of writing, high-quality diagnostic accuracy evidence reporting sensitivity, specificity or likelihood ratios for the Cervical Rotation Lateral Flexion Test as a stand-alone diagnostic test appears limited.

A 2022 study by Koppenhaver and colleagues examined the validity of the CRLF Test and manual examination in predicting whether people with neck pain may benefit from manipulation directed to the first and second rib. The study is useful because it reflects the test’s role in clinical reasoning, but it does not mean the CRLF Test confirms first rib dysfunction or diagnoses a condition.

A Delphi investigation into first rib dysfunction in people with neck and shoulder pain found that experts considered the CRLF Test useful, but also questioned its diagnostic accuracy and interpretation in isolation. The same work emphasised a cluster of findings rather than reliance on one test.

Therefore, the CRLF Test should be interpreted as a movement and symptom-response assessment rather than as a stand-alone diagnostic accuracy test.

Reliability and Validity

Reliability may depend on examiner experience, client position, amount of cervical rotation, amount of lateral flexion, force applied, symptom criteria and whether range is measured objectively.

Validity is stronger when the test finding is interpreted alongside a cluster of relevant findings such as painful or restricted neck movement, shoulder girdle loading symptoms, upper-limb neurodynamic findings, first rib palpation sensitivity, scalene sensitivity and response to related movements. Validity is weaker when the test is interpreted alone.

To improve consistency, professionals should record the exact protocol, side assessed, range, end-feel, symptom response and comparison side.

Common Errors and Limitations

Common errors include:

• Forcing end-range cervical movement
• Not recording which side was assessed
• Using different protocols across sessions
• Assuming a positive test confirms first rib dysfunction
• Ignoring dizziness or vascular symptoms
• Not comparing both sides
• Failing to record familiar symptom reproduction
• Treating general neck stiffness as diagnostic
• Not documenting end-feel or symptom location
• Using the test alone to guide decisions

Limitations include variable protocol descriptions, limited stand-alone diagnostic evidence, overlap with cervical and shoulder symptoms, and difficulty isolating first rib movement.

Practical Applications

The CRLF Test can help professionals observe whether combined cervical movement is limited or symptom-provoking. It may guide further assessment of cervical ROM, first rib palpation, shoulder girdle movement, thoracic outlet symptoms and upper-limb neural sensitivity.

It is also useful for education because it teaches professionals to record movement restriction and symptom behaviour carefully. A clear Measurz record allows the professional to compare side-to-side findings and monitor whether movement or symptoms change over time.

How to Record This in Measurz

In Measurz, record:

• Test name: Cervical Rotation Lateral Flexion Test
• Client position: seated or supine
• Side assessed
• Direction of rotation
• Direction of lateral flexion
• Range or estimated restriction
• Measurement method if used
• End-feel
• Pain or symptom score before, during and after
• Symptom location
• Symptom quality
• Whether symptoms were familiar
• Dizziness, vascular or neurological symptoms if present
• Result: positive, negative, unclear or unable to test
• Comparison side
• Confidence in result
• Related first rib palpation, cervical ROM, shoulder ROM, upper-limb neurodynamic and thoracic outlet findings
• Reason for stopping if relevant
• Retest date if relevant

Recording these details improves repeatability, communication, assessment reasoning, client education, monitoring over time and reporting quality.

Related Tests / Internal Links

• Cervical Flexion Rotation Test
• Cervical Distraction Test
• Spurling’s Test
• Bakody Sign
• Adson’s Test
• Halstead Test
• Eden Test
• Roos Stress Test
• Wright Test
• Cervical ROM Assessment
• Shoulder ROM Assessment
• Upper Limb Tension Test

FAQs

What is the Cervical Rotation Lateral Flexion Test used for?

It is used to observe cervical, cervicothoracic and possible first rib-related movement restriction or symptom response.

What is a positive CRLF Test?

A positive finding may include reduced range, asymmetry, altered end-feel or familiar symptom reproduction during the test movement.

Does the CRLF Test diagnose first rib dysfunction?

No. It may support first rib or cervicothoracic assessment reasoning, but it does not confirm first rib dysfunction on its own.

Is the test used for thoracic outlet syndrome?

It may be included in broader thoracic outlet reasoning, but it does not diagnose TOS.

What is a negative CRLF Test?

A negative result means no meaningful restriction, asymmetry or familiar symptom reproduction occurred during the test.

Why should the protocol be recorded?

Different variations exist, so recording rotation direction, lateral flexion direction and side assessed improves repeatability.

What should be recorded in Measurz?

Record side, movement directions, range, end-feel, symptoms, comparison side, confidence and related cervical or thoracic outlet findings.

Key Takeaways

The Cervical Rotation Lateral Flexion Test is a movement and symptom-response assessment.
It is commonly used in first rib and cervicothoracic assessment reasoning.
A positive result does not confirm first rib dysfunction or thoracic outlet syndrome.
The test is more useful when combined with a cluster of related findings.
Measurz should capture side, movement direction, range, symptoms, end-feel and related findings.

References

Koppenhaver, S. L., Morel, T., Dredge, G., Baeder, M., Young, B. A., Petersen, E. J., Fernández-de-Las-Peñas, C., & Gill, N. (2022). The validity of the cervical rotation lateral flexion test in predicting benefit after manipulation treatment to the first and second rib. Musculoskeletal Science and Practice, 62, 102629. https://doi.org/10.1016/j.msksp.2022.102629

Mastromarchi, P., & May, S. (2021). First rib dysfunction in patients with neck and shoulder pain: A Delphi investigation. Journal of Manual & Manipulative Therapy, 29(3), 181–188. https://doi.org/10.1080/10669817.2020.1819897

Masocatto, N. O., Da-Matta, T., Prozzo, T. G., Couto, W. J., & Porfirio, G. (2022). Thoracic outlet syndrome: A narrative review. Frontiers in Cardiovascular Medicine, 9, 802183. https://doi.org/10.3389/fcvm.2022.802183

Dessureault-Dober, I., Bronchti, G., & Bussières, A. (2018). Diagnostic accuracy of clinical tests for neurogenic and vascular thoracic outlet syndrome: A systematic review. Journal of Manipulative and Physiological Therapeutics, 41(9), 789–799. https://doi.org/10.1016/j.jmpt.2018.02.007