External Rotation Lag Sign

What are rotator cuff tears?

The rotator cuff comprises four muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) and their corresponding tendons surrounding the shoulder joint. It provides stability and allows for a wide range of arm movements. The rotator cuff is essential because it helps an individual lift, rotate, and reach overhead to guarantee pain-free shoulder movement for daily tasks and athletic activities.

When an individual falls on an outstretched arm or experiences degenerative changes due to aging and repetitive stress, rotator cuff tears can occur. These tears happen when the tendons of the rotator cuff muscles are torn, either partially or completely. Full-thickness tears, where the tendon is completely detached, are particularly severe and can significantly impair shoulder function. Older individuals and those whose occupations or sports involve repetitive overhead activities are more prone to rotator cuff tears.

Symptoms

Symptoms of rotator cuff tears typically include shoulder pain, weakness, and limited range of motion. The pain often worsens at night or with activities that involve lifting or rotating the arm. A grating sensation (crepitus) may also occur with certain shoulder movements (Athwal & Armstrong, 2022; Johns Hopkins Medicine, 2022). In clinical settings, the presence of lag signs during an External Rotation Lag Sign test can indicate the severity of the tear, helping healthcare professionals diagnose and manage the condition effectively.

How to diagnose rotator cuff tears

To diagnose rotator cuff injuries, doctors use a combination of medical history, physical exams, and imaging tests (Johns Hopkins Medicine, 2022; University of Pittsburgh Medical Center, n.d.). These methods help identify the presence, type, and severity of rotator cuff pathology.

Medical history and physical exam

A healthcare professional will first review the patient's medical history, focusing on any previous shoulder or muscle injuries. During the physical exam, they will assess the shoulder's range of motion and muscle strength while asking about shoulder pain and its impact on daily activities. They may also touch and press around the shoulder to check for tenderness or abnormalities. These steps help form the clinical diagnosis and identify any lag signs that might indicate rotator cuff disease.

Murrell and Walton (2001) state that if all three of the following tests: supraspinatus weakness, weakness in external rotation, and impingement are positive, or if two are positive in a patient aged 60 or older, there is a 98% chance of a rotator cuff tear. Their absence rules out the diagnosis.

X-ray

Another method for diagnosis is an X-ray. X-rays help rule out bone spurs or osteoarthritis as the cause of the patient's symptoms. This is a common first step in diagnosing rotator cuff injuries because they are quick and non-invasive.

Magnetic resonance imaging (MRI)

Aside from the aforementioned two, an MRI is essential for seeing the soft tissue in the shoulder, helping healthcare professionals determine if the rotator cuff tear is partial-thickness or full-thickness. An MRI can also reveal information about tendon retraction or tear patterns, such as supraspinatus tears, influencing surgical decisions. It is particularly useful for patients with severe symptoms or those considering surgery.

Ultrasound

Ultrasound is helpful for assessing the rotator cuff for signs of inflammation or tears as the shoulder is moved into different positions. This makes them ideal for evaluating patients with acute pain or needing an immediate assessment of thickness rotator cuff tears or a rotator cuff rupture.

What is the External Rotation Lag Sign test?

The External Rotation Lag Sign test evaluates the strength of the supraspinatus and infraspinatus muscles, which are key rotator cuff components. It helps diagnose shoulder issues by assessing muscle integrity and detecting tears, particularly in cases of impingement syndrome.

How to conduct the External Rotation Lag Sign test?

To conduct the test, just follow these steps:

1. Position the patient: The patient can be seated or standing.
2. Set the arm: The examiner passively flexes the patient's elbow to 90 degrees while keeping the shoulder at 20 degrees of elevation in the scapular plane, with the arm in near maximum external rotation.
3. Support the elbow: The examiner supports the elbow and holds the arm in external rotation at the wrist.
4. Test the lag: The patient is asked to maintain the position as the examiner releases the hold at the wrist, assessing the shoulder's degree of lag or movement.

Scoring

To evaluate the External Rotation Lag Sign test, the examiner should look for the degree of lag. This is the patient's inability to maintain the externally rotated shoulder position after the examiner releases their support.

• Negative test: The test is considered negative if the patient can keep the shoulder in the externally rotated position after the examiner releases the hold.
• Positive test: The test is positive if the patient cannot maintain the position and the shoulder rotates internally when the examiner releases the hold.

How does our External Rotation Lag Sign test template work?

To simplify your examination process, we’ve created a convenient External Rotation Lag Test template. Here’s how to use it:

Step 1: Download the template

Scrolling through our guide, you will see an image of our blank template. Hover on the image, then click on the download button.

Step 2: Use during examinations

Fill out the patient’s details and explain the procedure to them. Our template includes step-by-step instructions for both you and your patients. What's even more amazing is that it has sections to record the test result (whether positive or negative) and a space for additional notes on the patient’s test results or conditions.

Step 3: File for reference

Save the completed document for future reference. This will help you track the patient’s history and monitor their progress over time.

What are the next steps?

After diagnosing a rotator cuff tear, creating a tailored treatment plan for the patient is the most important step. You may recommend physical therapy to enhance shoulder strength and mobility and assess if surgery is required based on the severity of the tear and the patient's response to therapy. For severe tears or cases that don't seem to have an improvement, surgical intervention might be necessary. Other than that, regular follow-ups should be conducted to monitor the patient’s progress, adjust the treatment plan, and ensure optimal recovery.

References

Athwal, G. S., & Armstrong, A. D. (2022, June). Rotator cuff tears. American Academy of Orthopaedic Surgeons. https://orthoinfo.aaos.org/en/diseases--conditions/rotator-cuff-tears/

Hospital for Special Surgery. (2019, December 16). Rotator cuff pain, tears and other injuries & treatments. https://www.hss.edu/condition-list_rotator-cuff-injuries.asp

Johns Hopkins Medicine. (2022). Rotator cuff injury. https://www.hopkinsmedicine.org/health/conditions-and-diseases/rotator-cuff-injury

Murrell, G. A., & Walton, J. R. (2001). Diagnosis of rotator cuff tears. The Lancet, 357(9258), 769–770. https://doi.org/10.1016/s0140-6736(00)04161-1

University of Pittsburgh Medical Center. (n.d.). Diagnosing torn rotator cuff. Retrieved July 20, 2024, from https://nyulangone.org/conditions/torn-rotator-cuff/diagnosis