The Cervical Rotation Lateral Flexion Test is used to assess whether cervical lateral flexion is restricted after rotating the neck, often as part of first rib mobility assessment. A 2022 study examined whether the test predicted benefit from manipulation to the first and second rib, supporting the need to treat it as one clinical finding rather than a stand-alone decision rule.
A client reports neck and shoulder girdle symptoms, often with tightness near the upper trapezius, scalene or first rib region. Neck movement may feel restricted, and shoulder girdle loading may reproduce symptoms. The Cervical Rotation Lateral Flexion Test may help assess whether movement is limited in a way that could be consistent with first rib or upper thoracic contribution.
The test should not be used alone to diagnose first rib dysfunction. Current expert and validity literature suggests that first rib assessment should include multiple findings, such as neck movement, palpation, neural tests and response to loading.
Test name: Cervical Rotation Lateral Flexion Test
Also known as: CRLF Test
Body region: Cervical spine, first rib, upper thoracic region and shoulder girdle
Purpose: Assess cervical lateral flexion restriction after rotation, commonly in first rib assessment
Positive finding: Restricted lateral flexion compared with the other side or expected range
Negative finding: No meaningful restriction or side-to-side difference
Best used with: Neck ROM, first rib palpation, shoulder girdle loading, upper limb neurodynamic testing and thoracic outlet screen
Key limitation: It should not be used alone to diagnose first rib dysfunction or decide treatment
The Cervical Rotation Lateral Flexion Test is performed by rotating the neck, then laterally flexing the cervical spine. The test is often used to assess whether the first rib or upper thoracic region may be contributing to restricted movement.
Protocols vary, so exact positioning and interpretation criteria should be recorded clearly.
The test is used to observe whether lateral flexion is restricted after cervical rotation and whether the finding fits with first rib or upper thoracic symptoms.
It may help inform whether further first rib, scalene, thoracic outlet, cervical or shoulder girdle assessment is useful.
The test assesses movement restriction and sometimes symptom response during a combined cervical movement. It does not directly measure first rib position or prove first rib dysfunction.
This test may be useful for clients with neck pain, shoulder girdle symptoms, upper trapezius or scalene-region symptoms, symptoms with shoulder girdle loading, or suspected first rib contribution.
Use when first rib or upper thoracic contribution is part of the reasoning and the client can tolerate cervical rotation and lateral flexion safely.
Use caution with dizziness, vascular symptoms, acute trauma, suspected instability, severe neck pain, neurological symptoms, thoracic outlet vascular signs or symptoms that worsen rapidly with cervical positioning.
Chair or standing space
Pain/symptom scale
Measurz recording workflow
Optional video notes
Optional first rib palpation notes
Position the client sitting or standing upright.
The client maintains relaxed shoulders and neutral trunk posture.
Stand behind or beside the client to observe neck motion and shoulder elevation.
Manual contact may be used to guide the head and monitor shoulder girdle movement, depending on the selected method.
Avoid shoulder hiking, trunk lean and excessive cervical extension.
Rotate the cervical spine toward one side, then laterally flex the head away or according to the selected protocol. Repeat on the opposite side.
Ask the client to report pain, tightness, pulling, neural symptoms, dizziness or familiar symptoms.
A positive finding is restricted lateral flexion or meaningful side-to-side difference, especially when it fits the client’s symptom pattern.
A negative finding is no meaningful restriction or symptom reproduction.
Stop if dizziness, neurological symptoms, vascular symptoms, sharp pain or poor tolerance occurs.
Do not force cervical motion. Record whether the finding is movement restriction, symptom reproduction or both.
A positive CRLF Test may suggest restricted cervical/upper thoracic movement that could be related to first rib or shoulder girdle mechanics. It does not diagnose first rib dysfunction.
A negative test suggests no obvious restriction under the tested setup. It does not exclude first rib, cervical, shoulder or thoracic outlet contribution.
Interpretation is stronger when combined with first rib palpation, neck ROM, shoulder girdle loading, upper limb neural testing, thoracic outlet screening and response to movement.
A 2020 Delphi investigation on first rib dysfunction reported that experts considered the cervical rotation lateral flexion test useful, but questioned its diagnostic accuracy and interpretation when used in isolation.
A 2022 study examined the validity of the CRLF Test for predicting benefit after manipulation to the first and second rib, but this should not be interpreted as confirming diagnostic accuracy for first rib dysfunction.
No stand-alone sensitivity, specificity or likelihood ratio values are listed.
Current evidence suggests the test may have clinical use as part of a broader assessment, but its validity as a stand-alone first rib diagnostic test is uncertain. Expert consensus supports using it alongside neck movement, shoulder girdle loading, palpation and neural tests rather than alone.
Common errors include forcing cervical motion, not comparing sides, ignoring shoulder hiking, treating restriction as a diagnosis, failing to record symptoms and using the test alone to decide treatment.
Limitations include variable protocols, cervical mobility influence, thoracic contribution, symptom overlap, examiner technique and uncertain stand-alone diagnostic accuracy.
Use the Cervical Rotation Lateral Flexion Test to document combined cervical movement restriction and symptom response. It may help guide further first rib, cervical, neural or shoulder girdle assessment.
Record test name, direction tested, side of restriction, pain score, symptom location, movement quality, degree of restriction if measured, shoulder compensation, dizziness or neurological symptoms, comparison side, confidence in result and related findings.
Add first rib palpation, neck ROM, shoulder ROM, upper limb neurodynamic tests, thoracic outlet screen and shoulder girdle loading notes.
Neck Rotation Test
Neck Lateral Flexion Test
Adson’s Test
Roos Stress Test
Wright Test
Upper Limb Tension Test
Shoulder ROM Tests
Thoracic Mobility Assessment
It assesses cervical lateral flexion restriction after cervical rotation, often as part of first rib assessment.
No. It may support clinical reasoning but does not diagnose first rib dysfunction on its own.
Restricted lateral flexion or meaningful side-to-side difference, especially if it matches the symptom pattern.
Neck ROM, shoulder girdle loading, first rib palpation, neural testing and thoracic outlet screening.
Record direction, side, restriction, symptoms, compensation, dizziness or neurological symptoms and related findings.
The CRLF Test assesses combined cervical movement restriction.
It is often used in first rib assessment but is not diagnostic alone.
Current evidence questions isolated interpretation.
Use it with neck, shoulder, neural and first rib findings.
Measurz should capture side, restriction, symptoms and related tests.
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. Needs verification.
Mastromarchi, P., & May, S. (2020). First rib dysfunction in patients with neck and shoulder pain: A Delphi investigation. Musculoskeletal Science and Practice, 50, 102251. Needs verification.
