8.1 Cervical Spine & Thoracic Outlet Syndrome Tests

Cervical Spine & Thoracic Outlet Syndrome Tests

Clinical Core: Orthopedic provocation of the cervical spine and thoracic outlet requires precise knowledge of segmental neuroanatomy and biomechanics. In Canadian practice, therapists utilize validated clinical prediction clusters—such as Wainner's radiculopathy cluster—while rigorously screening for vertebrobasilar arterial insufficiency (VAI) before initiating manual treatment or joint mobilization.

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1. Principles of Cervical Orthopedic Provocation

Orthopedic special tests in the cervical spine are designed to isolate anatomical tissue sources responsible for neck pain, headache, and upper extremity paresthesias. Because the cervical spine houses both the spinal cord and exiting nerve roots while facilitating three-dimensional mobility of the cranium, assessment requires careful differentiation between localized zygapophyseal (facet) irritation, uncovertebral arthrosis, discogenic radiculopathy, and vascular compromise.

Biomechanics of the Intervertebral Foramen

The dimensions of the cervical intervertebral foramina change predictably during physiological spinal motion:

• Flexion and Contralateral Lateral Flexion: Widen the neural foramina and decompress the nerve root.
• Extension and Ipsilateral Lateral Flexion: Measurably narrow the foraminal diameter and cross-sectional area.

Provocative maneuvers exploit these kinematic changes to reproduce or relieve neurodynamic compromise.

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2. Cervical Radiculopathy & Wainner's Clinical Prediction Rule

Cervical radiculopathy arises when an exiting cervical nerve root is inflamed or mechanically compressed by a herniated nucleus pulposus, uncovertebral joint osteophytes (joints of Luschka), or facet hypertrophy. While individual orthopedic tests often lack diagnostic reliability in isolation, Wainner et al. (2003) established a multi-test clinical prediction rule (CPR) that provides exceptional diagnostic accuracy for cervical nerve root entrapment.

+---------------------------------------------------------------------------------+
|                   WAINNER'S CLINICAL PREDICTION RULE CLUSTER                    |
+-------------------+-------------------------------------+-----------------------+
| TEST NAME         | TESTING MECHANISM                   | POSITIVE CRITERION    |
+-------------------+-------------------------------------+-----------------------+
| 1. Spurling's A   | Extension, ipsilateral side-bending,| Sharp radiating pain  |
|    (Compression)  | axial downward compressive force    | down ipsilateral arm  |
| 2. Distraction    | Supine/seated axial traction force  | Relief/abolishment of |
|    Test           | (approx. 10–15 kg / 20–30 lbs)      | radicular arm pain    |
| 3. ULTT A         | Scapular depression, 110° abd, ext, | Peripheral pain or    |
|    (Median Bias)  | wrist/finger ext, contralateral sb  | >10° side difference  |
| 4. Cervical       | Active or passive cervical rotation | Measured rotation     |
|    Rotation       | to the involved, symptomatic side   | less than 60 degrees  |
+-------------------+-------------------------------------+-----------------------+
  2 Positive Tests: +LR 0.88 (post-test ~21%) | 3 Positive Tests: +LR 6.1 (post-test ~65%)
  4 Positive Tests: +LR 30.3 (post-test ~90%; specificity 99%, sensitivity 24%)

1. Spurling's Test (Neck Compression Test)

Spurling's test directly narrows the ipsilateral intervertebral foramen, driving articular osteophytes or disc material into the exiting nerve root:

• Spurling's Test A (Classic): The patient sits upright. The therapist passively moves the cervical spine into extension and ipsilateral lateral flexion toward the symptomatic side. The therapist then carefully applies a gradual downward axial compressive force through the cranium.
• Spurling's Test B: Adds ipsilateral cervical rotation to the extension and lateral flexion prior to axial compression, producing maximal foraminal closure.
• Positive Finding: Sharp, shooting, electrical, or lancinating radicular pain that radiates past the shoulder into the upper extremity following a distinct dermatomal pattern (e.g., thumb and index finger for C6, middle finger for C7).
• Critical Distinction: Localized neck soreness, paraspinal muscular cramping, or dull aching over the ipsilateral cervical facet pillar is not a positive Spurling's test; this represents facet joint irritation (cervical capsulitis or facet arthrosis) rather than true nerve root radiculopathy.

2. Cervical Distraction Test

The Cervical Distraction test serves as a mechanical counter-test to Spurling's, widening the neural foramina and relaxing dural sleeve tension:

• Execution: The patient lies supine with the head in neutral. The therapist stands at the head of the table, placing one hand beneath the patient's occiput and the other hand cupping the mandible or forehead. The therapist smoothly applies a sustained axial distraction force of approximately 10 to 15 kg (20 to 30 lbs) for 10 to 15 seconds.
• Positive Finding: The significant alleviation, mitigation, or complete abolishment of the patient's familiar radiating upper extremity radicular pain or paresthesia.
• Clinical Meaning: Alleviation of radicular symptoms confirms that foraminal decompression relieves nerve root impingement. If the patient only reports a reduction in localized muscular stiffness, the test is negative for radiculopathy.

3. Upper Limb Tension Test A (ULTT A / Elvey with Median Nerve Bias)

ULTT A assesses the mechanosensitivity and excursion of the cervical nerve roots (particularly C5, C6, and C7) and the median nerve:

1. Scapular Stabilization: The patient lies supine; the therapist depresses the shoulder girdle on the tested side.
2. Glenohumeral Abduction: Abduct the arm to 110° with the elbow flexed at 90°.
3. Distal Extension: Passively extend the patient's wrist and all fingers.
4. Forearm Supination: Supinate the forearm.
5. Elbow Extension: Passively extend the elbow while maintaining scapular depression and wrist extension.
6. Structural Differentiation / Sensitizer: The patient is asked to actively lateral-flex their cervical spine away from the tested side (contralateral side-bending). This increases proximal neural tension. Then, they lateral-flex toward the tested side (ipsilateral side-bending), which slacks the nerve root.

• Positive Finding: Reproduction of the patient's familiar upper extremity symptoms, a significant difference in elbow extension range (>10°) between limbs, and symptom alteration during cervical lateral flexion (worsening with contralateral bending, improving with ipsilateral bending).

4. Ipsilateral Cervical Rotation <60°

• Procedure: The therapist measures active or passive cervical rotation toward the symptomatic side using a goniometer or inclinometer.
• Positive Finding: Rotation range of motion less than 60°.
• Clinical Significance: Acute inflammation of the nerve root and dural sleeve induces involuntary protective spasm of the ipsilateral rotator musculature (splenius capitis, levator scapulae, upper trapezius) to prevent foraminal narrowing.

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3. Cervical Arterial Dysfunction & Vertebral Artery Testing (VAT)

The vertebral arteries arise from the subclavian arteries, enter the transverse foramina of C6, ascend through C6 to C1, sweep over the posterior arch of the atlas within the suboccipital triangle, and enter the skull through the foramen magnum to form the basilar artery. The vertebrobasilar system supplies the brainstem, cerebellum, and occipital lobes.

   SUBCLAVIAN ARTERY ---> TRANSVERSE FORAMINA (C6-C1) ---> POSTERIOR ARCH OF ATLAS
                                                                   |
                                                            FORAMEN MAGNUM
                                                                   |
   BRAINSTEM & CEREBELLUM <--- BASILAR ARTERY <--- VERTEBRAL ARTERY JUNCTION

Hemodynamics of Cervical Rotation & Extension

When the head is rotated fully to one side, the contralateral vertebral artery is stretched and compressed against the transverse process of the atlas and the posterior atlantoaxial membrane. In a healthy vascular system, the ipsilateral vertebral artery maintains adequate compensatory perfusion. However, if the ipsilateral artery is compromised by atherosclerosis, dissection, or anatomical hypoplasia, extreme cervical rotation and extension can induce brainstem ischemia.

Vertebral Artery Test (VAT / Wallenberg Test / DeKleyn's Test)

• Patient Setup: The patient is positioned supine (strongly preferred over seated because a patient who experiences a syncopal drop attack while seated is at immediate risk of falling).
• Procedure:
  1. The therapist supports the patient's cranium and slowly guides the neck into passive full cervical extension.
  2. The therapist then slowly rotates the head fully to one side and adds ipsilateral lateral flexion.
  3. The position is held steadily for 30 seconds.
  4. Throughout the test, the therapist maintains direct eye contact with the patient, observes the pupillary responses, and engages the patient in conversation (e.g., counting backwards or answering simple questions) to monitor speech and cognitive clarity.
  5. The therapist returns the head to neutral for 20 to 30 seconds of rest before repeating the procedure on the opposite side.

The Red Flag Symptom Complex: The "5 Ds and 3 Ns"

Reproduction of any of the following cardinal signs constitutes a positive test and indicates vertebrobasilar insufficiency:

Mandatory Clinical Action for Positive VAT

1. Immediate Cessation: Stop testing immediately and return the patient's head to neutral.
2. Emergency Escalation: Keep the patient supine and calm, monitor vital signs, and refer for emergency medical evaluation or immediate vascular imaging (Doppler ultrasound, MR angiography).
3. Absolute Contraindication: A positive VAT or reported history of the 5 Ds and 3 Ns is an absolute contraindication to end-range cervical joint mobilization, aggressive myofascial stretching of the suboccipital triangle, and mechanical cervical traction.

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4. Thoracic Outlet Syndrome (TOS) Provocative Tests

Thoracic Outlet Syndrome describes compression of the neurovascular bundle—consisting of the brachial plexus (C5–T1 roots/trunks) and the subclavian artery and vein—as it travels from the base of the neck into the axilla. TOS is classified anatomically according to three distinct entrapment spaces:

1. Interscalene Triangle: Bound by the anterior scalene anteriorly, the middle scalene posteriorly, and the first rib inferiorly. Houses the brachial plexus trunks and subclavian artery (the subclavian vein passes anterior to the anterior scalene).
2. Costoclavicular Space: Bound by the clavicle anteriorly, the first rib posteriorly, and the subclavius muscle. Houses the divisions of the brachial plexus and both subclavian vessels.
3. Subcoracoid / Pectoralis Minor Space: Bound by the pectoralis minor tendon anteriorly, the coracoid process superiorly, and the ribs/chest wall posteriorly. Houses the cords of the brachial plexus and axillary vessels.

   INTERSCALENE TRIANGLE             COSTOCLAVICULAR SPACE            SUBCORACOID TUNNEL
   [Ant. & Mid. Scalenes]            [Clavicle & 1st Rib]             [Pectoralis Minor]
             |                                |                                |
      Adson's Maneuver                   Eden's Test                     Wright's Test
             \                                |                               /
              +-------------------------------+------------------------------+
                                              |
                                     ROOS TEST (EAST)
                               [3-Minute Dynamic Endurance]

1. Adson's Maneuver (Interscalene Triangle)

• Target Structure: Anterior scalene muscle compressing the subclavian artery and brachial plexus against the first rib.
• Procedure: The patient sits upright with the arm abducted 30° and slightly extended. The therapist palpates the radial pulse at the wrist. The patient is instructed to fully extend their neck, rotate their head toward the symptomatic side, take a deep breath, and hold it for 15 to 30 seconds.
• Positive Finding: Significant diminution or complete obliteration of the radial pulse, accompanied by reproduction of the patient's familiar paresthesias down the arm.
• Modified Adson's (Halstead Maneuver): The patient rotates the head away from the symptomatic side, extending the neck. This variant specifically stretches and tests the middle scalene muscle.

2. Eden's Test / Costoclavicular Test

• Target Structure: Costoclavicular space (clavicle and first rib).
• Procedure: The patient sits upright in an exaggerated "military posture"—chest thrust forward, shoulders depressed and drawn backwards into maximal retraction. The therapist monitors the radial pulse bilaterally.
• Positive Finding: Marked reduction or absence of the radial pulse, accompanied by tingling or numbness along the medial arm, forearm, and ulnar hand (C8–T1 distribution).
• Mechanism: Retraction and depression of the clavicle mechanically narrows the space between the clavicle and the first rib, compressing the neurovascular bundle.

3. Wright's Hyperabduction Test (Pectoralis Minor / Subcoracoid Space)

• Target Structure: Subcoracoid space beneath the pectoralis minor tendon.
• Procedure: Performed with the patient seated or supine. The therapist palpates the radial pulse and passively hyperabducts the patient's arm to 180° in the coronal plane, accompanied by full glenohumeral external rotation. The position is held for 1 minute.
• Positive Finding: Disappearance or significant weakening of the radial pulse, accompanied by ischemic heaviness or paresthesias in the extremity.
• Mechanism: The pectoralis minor tendon is stretched taut across the coracoid process, compressing the underlying axillary artery and brachial plexus cords against the thoracic wall.

4. Roos Test / Elevated Arm Stress Test (EAST)

• Target Structure: General screening for neurovascular TOS across all three anatomical portals.
• Procedure: The patient sits upright with bilateral shoulders abducted to 90°, externally rotated to 90°, and elbows flexed to 90° ("surrender" position). The patient is instructed to slowly open and close their hands into tight fists once every second for 3 full minutes.
• Positive Finding: Inability to maintain the test position for the full 3 minutes, progressive ischemic pain, weakness, drooping of the arms, profound tingling down the fingers, or visible pallor or cyanosis of the hands.
• Clinical Significance: Considered the most clinically sensitive provocative screening test for TOS. A healthy individual experiences mild muscular fatigue in the forearm and shoulder, but no neurological or ischemic signs.

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5. Cervical & TOS Special Test Matrix

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6. Clinical Application Vignette

A 44-year-old administrative assistant presents with a 6-week history of numbness and tingling in the right lateral forearm, thumb, and index finger, exacerbated by prolonged keyboard use and looking up at an elevated monitor. Static palpation reveals hypertonicity in the scalenes and suboccipitals.

During assessment:

• Spurling's A reproduces sharp, electrical shooting pain down the anterolateral forearm into the thumb and index finger (C6 dermatome).
• Cervical Distraction completely relieves the tingling in the hand.
• ULTT A reproduces the exact lateral forearm symptoms at 30° of elbow flexion, which intensifies when the patient tilts their head to the left (contralateral side-bending).
• Active cervical rotation to the right is restricted to 48° due to sharp pain.
• Adson's maneuver and Roos test are negative, with no change in radial pulse or reproduction of symptoms.

Clinical Reasoning: The patient tests positive on all 4 components of Wainner's clinical prediction rule (Spurling's, distraction, ULTT A, rotation <60°), which in Wainner's study corresponded to a post-test probability of about 90% for cervical radiculopathy (here, consistent with right C6). The negative TOS tests confirm that the primary pathology is cervical nerve root compression within the intervertebral foramen, not peripheral thoracic outlet entrapment.