What is the purpose of the side-lying test (also known as the lateral decubitus test)?

From the Guidelines

The side-lying test, also known as the lateral side-lying recovery position, is recommended for unresponsive individuals who are breathing normally, as it may help increase total airway volume and decrease stridor severity, according to the 2015 American Heart Association and American Red Cross guidelines update for first aid 1. When performing this test, it is essential to extend one of the person's arms above the head and roll the body to the side so that the person's head rests on the extended arm, then bend both legs to stabilize the body.

• The test is not recommended for individuals with suspected neck, back, hip, or pelvic injuries, as rolling them onto their side may cause further injury 1.
• If the person is unresponsive and not breathing normally, basic life support guidelines should be followed instead 1.
• The side-lying test is a simple and effective way to help maintain a patient's airway and breathing, and it is an essential skill for first aid providers to learn, as emphasized in the 2015 guidelines update 1. Key considerations when using the side-lying test include:
• Ensuring the person's airway is clear and they are breathing normally
• Avoiding movement that may cause further injury, especially in cases of suspected neck, back, hip, or pelvic injuries
• Following basic life support guidelines if the person is unresponsive and not breathing normally The 2015 American Heart Association and American Red Cross guidelines update for first aid provides the most recent and highest-quality evidence for the use of the side-lying test, and it is essential to follow these guidelines to ensure the best possible outcomes for patients 1.

From the Research

Side Lying Test

• The side lying test is not explicitly mentioned in the provided studies, however, some studies discuss various physical examination tests used to assess hip instability, which may be relevant to the side lying test.
• The study 2 discusses the diagnostic accuracy of three physical examination tests, including the abduction-hyperextension-external rotation (AB-HEER) test, the prone instability test, and the hyperextension-external rotation (HEER) test, in assessing hip microinstability.
• Another study 3 mentions the use of physical examination tests, such as the anterior apprehension, abduction-extension-external rotation, and prone external rotation tests, to diagnose hip microinstability.
• These studies suggest that physical examination tests can be useful in diagnosing hip instability and microinstability, but do not provide specific information on the side lying test.

Hip Instability Tests

• The study 4 mentions the use of hip instability tests, such as the posterior impingement and dial tests, to confirm the presence of instability.
• The study 2 discusses the use of the AB-HEER test, prone instability test, and HEER test to assess hip microinstability, and finds that the AB-HEER test is the most accurate.
• The study 3 discusses the use of a combination of physical exam maneuvers, including the anterior apprehension, abduction-extension-external rotation, and prone external rotation tests, to diagnose hip microinstability.

Diagnosis of Hip Instability

• The study 5 discusses the diagnosis and treatment of hip instability, and mentions the use of traction views of the affected hip to diagnose hip instability.
• The study 4 mentions the use of patient history, physical examination, and imaging studies to diagnose hip instability.
• The study 6 discusses the initial treatment of hip instability, which often begins with physical therapy to strengthen dynamic stabilizers and allow time for resolution of acute symptoms.