O'Brien Test

What is the O’Brien test?

The O’Brien test is a simple procedure that healthcare professionals use to assess shoulder pain. It can detect a cartilage (labral) tear or an acromioclavicular (AC) joint problem. It’s also called the active compression test.

When is the O’Brien active compression test performed?

Your shoulder is a large and complex joint. The O’Brien test focuses on your AC joint and labrum.

Your AC joint is one of four shoulder joints, where two bones meet. In your AC joint, the acromion (top outer edge of your shoulder blade, or scapula) meets the collarbone (clavicle). The O’Brien test can help diagnose a problem in your AC joint, such as separation in your joint or cartilage wear and tear.

Your labrum is a bumper-shaped piece of cartilage that lines the rim of the socket bone of your shoulder (glenoid). It helps stabilize the main ball-and-socket joint of your shoulder where the socket part of your shoulder blade (glenoid) and ball of the upper arm bone (humerus) meet. The O’Brien test can help diagnose a tear in the top or superior part of your labrum. A superior labrum tear is also called a SLAP tear, which stands for superior labrum, anterior to posterior.

The O’Brien test can also rule out other problems, such as:

• Rotator cuff tear.
• Shoulder impingement syndrome.
• Acromioclavicular joint arthritis or separation.

Who performs the shoulder O’Brien test?

Healthcare providers who may perform the O’Brien test include:

• Athletic trainers.
• Orthopedists (bone and joint specialists).
• Physical therapists.
• Primary care providers.

How does the O’Brien test for your shoulder work?

A healthcare provider asks you to:

• Raise your arms to 90 degrees (parallel to the floor) with your elbows fully extended. You may be sitting or standing.
• Bring your arms toward the center of your body slightly (10 to 15 degrees).
• Rotate your arms inward. The tops of your hands will face toward each other, and your thumbs will point down. Your elbows will face toward the outside of the body. This is called pronation.

Your healthcare provider presses down on your arms while standing in front of you or behind you. They ask you to resist the pressure and push the arms upward.

Next, the healthcare provider asks you to rotate your arms the other way. Your palms will face the ceiling, and your elbows will face the floor. This is called supination. Again, your healthcare provider presses down on your arms and asks you to resist.

What does a positive O’Brien test mean?

A positive O’Brien test means that you have pain in the first position but less pain in the second position. You must have reduced pain in the second position for the O’Brien test to be positive.

If the pain is deep in your shoulder, that may indicate a labral tear. With a labral tear, the test may also cause a clicking sound.

If the pain is closer to the surface at the top of your shoulder, that can mean you have an issue with your AC joint instead.

How do I prepare for the O’Brien test?

You don’t have to do anything to prepare for the active compression test. It’s a common procedure usually performed in a doctor’s office.

What should I expect after the O’Brien test?

After the test, your healthcare provider will talk to you about the results and what they might mean. They’ll also tell you whether you should have any other tests.

Is the O’Brien test reliable?

The active compression test can be positive in patients who have healthy shoulders. It’s one of many tools a healthcare provider uses to assess shoulder pain. It usually must be combined with other tests for an accurate, comprehensive diagnosis.

When should I know O’Brien test results?

You’ll know the results of the O’Brien test immediately. But it may be only one step in assessing shoulder pain. Your healthcare provider also may recommend:

• X-ray, CT scan or MRI to take pictures inside your shoulder.
• Blood tests to measure chemicals in the blood that indicate conditions such as gout or rheumatoid arthritis.
• Shoulder arthroscopy, a minimally invasive procedure used to examine your shoulder joints.

A note from Cleveland Clinic

The O’Brien test is a simple procedure to assess shoulder pain. It can help a healthcare provider determine whether you have a labral tear or an acromioclavicular joint problem. If you have shoulder pain, talk to a healthcare provider about what tests and treatments you might need.