Choosing the Best Clinical Tests for Shoulder Impingement Syndrome
At last count there were at least 20 different clinical tests to test patients with shoulder pain for subacromial impingement syndrome or SIS. And while that may seem like a good thing (so many helpful tests to choose from!), surgeons simply don't have the time to use each one on every patient with shoulder pain. Not only that, but by the end of all those tests, painful symptoms often get much worse.
The term impingement tells us something is getting pinched. Subacromial impingement syndrome occurs when the rotator cuff tendons rub against the roof of the shoulder, the acromion. Although SIS is one term, it actually represents a wide range of underlying pathologies. There could be a bursitis, rotator cuff tendinopathy, fracture, calcific tendinitis, or other change in the local anatomy contributing to the problem.
But before a plan of treatment can be determined, an accurate diagnosis is needed. That's where all these clinical tests come in. What surgeons, sports physicians, primary care physicians, and physical therapists need is a set of one to three clinical tests for subacromial impingement syndrome that are safe, reliable, and accurate.
In order to find such a set of accurate clinical tests for SIS, a group of researchers conducted a systematic review and meta-analysis. Systematic review means they carefully and systematically combed through all studies that might have had something to do with the subject. In this case their search found 1,338 articles that might qualify. On closer inspection, only 31 studies could actually be included.
A meta-analysis means when studies are too small to have much significance, they can be combined with other similar studies to reach statistical importance. They found five tests used and reported on most often in studies conducted around the world. These five tests included the Hawkins-Kennedy test, Neer's sign, the empty can test, the drop arm test, and the lift-off test.
Each of these tests is very familiar to physicians and others who examine patients with acute and chronic shoulder pain. These tests may recreate the impingement that is causing painful symptoms or stress weak muscles. Together, they help identify whether the problem is one of impingement, muscle strength/weakness, and whether the rotator cuff is partially or fully torn.
Athletes with sports injuries as well as adults with non-sports related injuries can be tested using these clinical tests. Each test has its own unique benefits and abilities in diagnosing shoulder problems. Accuracy in testing is essential to providing the best treatment for each shoulder problem.
After analyzing the data and reviewing the results from the 31 studies included, the authors made a few discoveries. All five of these tests are useful for diagnosing subacromial impingement syndrome. Three of these tests (Hawkins-Kennedy, Neer's, empty can) were better at ruling out (rather than ruling in) subacromial impingement syndrome (SIS). A negative Neer's sign is very reliable in showing that SIS is not the problem. When the drop arm and lift-off tests are positive, the likelihood of a SIS is strong.
The authors make several suggestions from the results of their study. First, they advise us that the Neer's sign, Hawkins-Kennedy test, and drop-arm test may provide some useful information but by themselves cannot yield an accurate diagnosis. The lift-off arm test is the most informative in confirming a subacromial impingement.
Other diagnostic test such as MRIs or arthroscopic exam may be needed to get the full picture of severity and underlying cause of the shoulder impingement. With an accurate diagnosis the most appropriate treatment can be prescribed whether that is physical therapy or surgery. In this way, unnecessary surgery can be avoided and overall costs of care reduced.
Marwan Alqunaee, RCSI, et al. Diagnostic Accuracy of Clinical Tests for Subacromial Impingement Syndrome: A Systematic Review and Meta-Analysis. In Archives of Physical Medicine and Rehabilitation. February 2012. Vol. 93. No. 2. Pp. 229-236.