If you’re suffering with shoulder pain or you’re somebody who helps others with shoulder pain, you may have encountered a battery of tests to help you figure out what’s causing the shoulder pain.
In the medical world, there’s a diagnosis called “shoulder impingement” or subacromial impingement that you can test for. There are at least 11 very popular physical tests for shoulder impingement. As with anything, not all tests are of equal value. So one question you might ask yourself is: “what are the best tests for shoulder impingement?”
In this article, we’re going to look at a research study that tried to determine the best tests for shoulder impingement and see what the researchers found!
The value of physical tests for subacromial impingement syndrome: a study of diagnostic accuracy examined the sensitivity, specificity, and overall accuracy of 11 shoulder impingement tests. You’ll be surprised to see how the tests performed, and you’ll learn what the results mean for you.
If you’d like to watch a video discussion of this study, check out this video:
What shoulder impingement tests are in the running?
Two of the most commonly used shoulder impingement tests are Neer’s sign and Hawkins and Kennedy. These are the front-runner tests in this study. Behind them are:
- Painful arc
- Abduction weakness
- Abduction pain
- External rotation weakness
- External rotation pain
- Empty can weakness
- Empty can pain
- Full can weakness
- Full can pain
Many non-medical professionals, like myself, often have the impression that these tests are all quite accurate and can definitively tell you why you’re in pain. If you test positive on a test, you’ve got the problem the test is looking for! It’s simple!
Unfortunately, not all tests are created equal, so we need to look more closely at just how accurate these tests are so we can find the best tests for shoulder impingement.
How did they set up this study on shoulder impingement tests?
The researchers took 34 people and did ultrasound scanning on their shoulders to use as the standard. If the ultrasound showed signs of shoulder impingement, then that was considered the correct answer. Ideally, the physical tests would match up to the findings of the ultrasound.
For example, if you were in the study, they would take an ultrasound of your shoulder. Then they’d run you through the 11 physical tests. If the ultrasound said you had shoulder impingement, then you had shoulder impingement. They’d then want to see which physical tests agree with that finding.
Understand this concept to understand the best tests for shoulder impingement.
To fully appreciate the results you need to understand the idea of “SPECIFICITY.” You may want to brush up on the idea of specificity here on wikipedia.
Basically, specificity tells you how good a test is at giving you a correct answer when someone DOES NOT have the condition the test is looking for. For example, if you do NOT have shoulder impingement, how good is the test at telling us that you DON’T have shoulder impingement?
Let’s go bigger. If have 100 people without shoulder impingement, will the test tell us that all 100 don’t have shoulder impingement? Or will it tell us 70 don’t and 30 do?
If the test has good specificity, it will tell us 100 people DON’T have shoulder impingement. That’s 100% specificity. If it tells us 30 people have shoulder impingement (that’s 30 wrong answers), then it has a specificity of 70%.
We can agree that a test that gives us that many wrong answers isn’t that good, right? Right. We don’t want 30 false positives out of 100. We want ZERO false positives if we can get it!
What was the most accurate test for shoulder impingement?
When running through all the patients and all the tests, the most accurate test for shoulder impingement was the Hawkins and Kennedy test. That means it was the one that was most often in agreement with the ultrasound. It scored a total accuracy of 74.1% – a solid C grade…
Does that make it the best test for shoulder impingement?
The specificity for Hawkins and Kennedy was 50%.
You read that correctly. 50% specificity.
That means if you did NOT have shoulder impingement, there was still a 50% chance Hawkins and Kennedy would give you a positive reading – a FALSE positive!
So not only is it only only 75% accurate overall, it’s also really good at giving you false positives.
Okay, so what about the second most accurate?
The second most accurate test for shoulder impingement was abduction pain. This is basically just lifting your arm out to the side. If you have pain doing it, it’s a positive result.
This test had an accuracy of only 57.6%. Specificity of 75%.
Pretty poor numbers.
What about the other tests? What about Neer’s sign?
Okay, so we’re still looking for the best tests for shoulder impingement. Okay.
Well, the other tests for shoulder impingement had even worse accuracy numbers. Neer’s sign, one of the shoulder impingement tests that gets a lot of good press, had accuracy of 54.5% and specificity of 0%!
That means Neer’s sign NEVER CORRECTLY IDENTIFIED A NEGATIVE CASE and was overall only as good as a coin toss.
The painful arc is another really common shoulder impingement test, and it was only 31% accurate with a specificity of 50%.
The numbers were all over the place with terrible accuracy and terrible specificities. In short, all the tests performed abysmally!
So what are the best shoulder impingement tests?
Based on this study, the shocking answer is that there are no best tests for shoulder impingement! They simply don’t exist!
Let’s put this in perspective. Imagine your dentist tells you he has a test for cavities. It’s 74.1% accurate, but a positive reading could be wrong 50% of the time. Would you trust that test to determine if you have cavities? Absolutely not!
What if you had two tests? Let’s add the second test. It’s accurate 57.6% of the time and a positive reading could still be wrong 25% of the time!
You’d be looking at your dentist with great skepticism. With accuracy and specificity numbers this bad, these shoulder impingement tests actually look to be more like elaborate diagnostic theater than useful tests.
The study looked at all these results and concluded: “As the predictive values of these tests are shown to be variable in this study it indicates that the clinical tests identified have limited use in informing diagnosis.”
In short: these shoulder impingement tests don’t work.
As trainers and mobility coaches, we are most interested in helping people build strength and mobility gradually and safely. We aren’t particularly concerned with medical diagnoses like “shoulder impingement” because the test results are so unreliable and don’t seem to mean much (what are you going to do with a positive result that has a 50% chance of being wrong?). And, as you can read in other articles on our site, surgery for shoulder impingement no longer seems to be the great holy grail it was once sold as.
We encourage you to find someone who will help you gradually and progressively increase your shoulder range of motion. If you can’t find someone, be that someone for yourself! There are tons of resources available online on YouTube (like our Shoulder Playlist). We also have a shoulder program that you may find helpful.
It’s your body. It’s your life. Take control!