How the Sulcus Test for Shoulder Instability Works

Woman describing her shoulder pain in doctor's office

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If you have shoulder pain, you may be having difficulty performing normal activities like reaching, lifting, or sleeping comfortably. Shoulder pain can also limit your ability to work or participate in recreational activities.

One of the challenges of managing your shoulder pain is determining which structure in your shoulder is causing the problem. Sometimes the weakness of your rotator cuff can cause structures in your shoulder to become pinched. After trauma, a shoulder fracture or AC joint separation may be the cause of your pain. Sometimes a labrum tear can cause problems with your shoulder like pain or difficulty reaching overhead.

Shoulder instability can also cause shoulder pain. This occurs when your shoulder dislocates after trauma. You may experience congenital shoulder instability without any specific injury, a condition known as multi-directional instability.

If you visit a physical therapist to manage your shoulder pain, he or she will likely perform shoulder special tests to help determine the cause of your shoulder pain. Tests like the apprehension test and relocation test help determine if your shoulder labrum may be torn. Another test for shoulder instability is the sulcus sign.

What Is the Sulcus Test?

The sulcus sign occurs in people with inferior shoulder instability. This can occur after an injury to your shoulder labrum that supports the front and underside of your shoulder joint.

The sulcus sign is simple to look for in a clinical examination. Here is how you do it:

  • You need a friend to help you look for the sulcus sign.
  • Sit or stand comfortably with your painful arm at your side.
  • Bend your elbow 90 degrees.
  • Have your friend hold your arm just above your elbow and gently but firmly pull your arm down.
  • Watch the top of your shoulder joint and look for the sulcus sign, which is when a small notch appears at the area where your arm attaches to your body.
  • If you see a small notch in the top of your shoulder, it indicates shoulder instability and a possible labrum tear.
  • Compare your injured shoulder with your uninjured shoulder.

If you perform the test and notice a sulcus sign, there is a chance that you have shoulder instability. You should see your doctor to help you further diagnose your shoulder problem. A course of physical therapy for shoulder instability may be useful as well to start working on improving your shoulder stability and rotator cuff strength. This can help decrease your shoulder pain and improve the way your shoulder moves and functions.

Remember, performing special tests on yourself is no substitute for a full examination by your doctor. Checking in with your physical therapist is also a good idea if you suspect you are having a problem with your shoulder.

The sulcus sign is a simple test to determine if shoulder instability may be a cause of your shoulder pain. When you understand the cause of your pain, you can then be sure to get the proper treatment and get back to your normal activities quickly and safely.

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