Adson's Test: Thoracic Outlet Syndrome (TOS), Positive, Wrist, Physical Therapy Purpose, Protocol & Diagnosis

Adson's Test:

• What is Adson's Test?
• Thoracic Outlet Syndrome (TOS)
• Positive Adson's Test
• Wrist Assessment
• Physical Therapy Purpose
• Protocol
• Diagnosis

What is Adson's Test?

Adson's Test is a physical examination maneuver used to evaluate patients for thoracic outlet syndrome (TOS), particularly when compression of the subclavian artery or brachial plexus is suspected. The test was developed by Dr. Alfred W. Adson and is commonly performed during orthopedic, neurological, and physical therapy assessments. It helps determine whether symptoms such as numbness, tingling, pain, or weakness in the arm may be related to compression of the neurovascular structures as they pass through the thoracic outlet.

Although Adson's Test is widely taught and remains part of many musculoskeletal examinations, it should not be used as the sole diagnostic tool. A positive result only suggests the possibility of thoracic outlet syndrome and must always be interpreted together with the patient's history, physical examination, and imaging or electrodiagnostic studies when necessary. The test is quick, non-invasive, and requires no special equipment, making it a valuable screening maneuver in clinical practice.

Thoracic Outlet Syndrome (TOS)

Thoracic outlet syndrome refers to a group of disorders caused by compression of the nerves, arteries, or veins that pass through the thoracic outlet, the space between the collarbone and the first rib. Depending on the structure involved, TOS is classified as neurogenic, venous, or arterial. Neurogenic TOS is the most common form and often presents with arm pain, numbness, tingling, and muscle weakness, while arterial or venous TOS may cause changes in skin color, swelling, coldness, or diminished pulses.

Adson's Test primarily evaluates possible arterial compression by assessing changes in the radial pulse during specific neck and arm movements. However, because thoracic outlet syndrome is a complex condition with overlapping symptoms, clinicians usually combine Adson's Test with other provocative maneuvers such as Wright's Test, Roos Test, or the Costoclavicular Test. Imaging studies, nerve conduction tests, and vascular ultrasound may also be needed to confirm the diagnosis and determine the exact site of compression.

Positive Adson's Test

A positive Adson's Test occurs when the patient's symptoms are reproduced and there is a noticeable reduction or disappearance of the radial pulse while the test is being performed. The patient may report numbness, tingling, pain, heaviness, or weakness in the affected arm. Some individuals may also experience a feeling of coldness or discomfort due to temporary vascular compression.

It is important to recognize that a diminished radial pulse alone does not confirm thoracic outlet syndrome because healthy individuals may also demonstrate pulse changes during extreme shoulder or neck positions. Therefore, clinicians place greater emphasis on reproducing the patient's typical symptoms rather than relying solely on pulse changes. A positive Adson's Test should prompt further evaluation but should not be considered definitive evidence of TOS without additional clinical correlation.

Wrist Assessment

During Adson's Test, the examiner places two or three fingers over the patient's radial artery at the wrist to monitor the pulse throughout the maneuver. The wrist itself is not being tested; instead, the radial pulse serves as an indirect indicator of blood flow through the subclavian artery. Any decrease or disappearance of the pulse may suggest compression of the vascular structures as the neck and shoulder are positioned.

Maintaining consistent finger pressure over the radial artery is essential because excessive pressure by the examiner can falsely weaken the pulse. The wrist should remain relaxed throughout the examination while the examiner focuses on changes in pulse strength and the patient's symptoms. Accurate pulse assessment improves the reliability of the test and helps reduce false-positive findings.

Physical Therapy Purpose

In physical therapy, Adson's Test is used as a screening tool during the assessment of patients with neck pain, shoulder pain, upper extremity numbness, or suspected thoracic outlet syndrome. Physical therapists use the results alongside posture evaluation, muscle flexibility testing, cervical spine examination, and functional movement analysis to determine whether neurovascular compression may contribute to the patient's symptoms.

The findings help guide rehabilitation planning rather than establish a final diagnosis. If thoracic outlet syndrome is suspected, treatment often focuses on posture correction, stretching of tight scalene and pectoralis muscles, strengthening of the scapular stabilizers, ergonomic education, and nerve gliding exercises. Repeating the test during follow-up visits may also help monitor changes in symptoms after therapy, although improvement should always be judged using overall clinical progress rather than the test result alone.

Protocol

The standard protocol for Adson's Test begins with the patient either sitting or standing comfortably while the examiner palpates the radial pulse of the affected arm. The patient's shoulder is positioned in slight extension and external rotation. The patient is then instructed to rotate the head toward the tested side, extend the neck, and take a deep breath while holding it briefly. Throughout the maneuver, the examiner carefully observes changes in the radial pulse and asks whether familiar symptoms are reproduced.

After completing the maneuver, the patient relaxes, and the examiner compares findings with the opposite side. The test should be performed gently to avoid unnecessary discomfort. If dizziness, severe pain, or neurological symptoms occur, the maneuver should be stopped immediately. Because no single provocative test has high diagnostic accuracy, Adson's Test is generally combined with other examination techniques to improve overall clinical assessment.

Diagnosis

Adson's Test contributes to the clinical diagnosis of thoracic outlet syndrome but is not considered diagnostic by itself. Modern clinical practice emphasizes combining patient history, symptom patterns, physical examination findings, and confirmatory investigations. Depending on the suspected type of TOS, additional studies may include Doppler ultrasound, CT angiography, MR angiography, MRI, electromyography (EMG), and nerve conduction studies.

A comprehensive diagnostic approach helps distinguish thoracic outlet syndrome from other conditions that can produce similar symptoms, including cervical radiculopathy, rotator cuff disorders, peripheral neuropathy, carpal tunnel syndrome, cubital tunnel syndrome, and vascular disease. Early and accurate diagnosis allows appropriate treatment, whether conservative management through physical therapy or, in selected severe cases, surgical decompression of the thoracic outlet.