If you have ever been told that you have a shoulder problem based on the position of your shoulder blade, or scapula, you might be able to rest a bit easier tonight. In a study published online today, researchers from VCU and USC tested the Scapula Diskinesis Test (SDT) to see if a positive result was indicative of pain or not. The test is commonly used by practicioners such as PTs and orthopedic physicians to determine if there is some type of dysfunction present. Simply, they watch the position of your shoulder blade as you move your arm, and if it sticks out too much (called winging) or if the rhythm doesn't match a standard ratio, the test is called positive, and they tell you (or they write a prescription) for Sick Scapula Syndrome.
To me, this is simply feeding the need to put a label on and diagnose all the "problems" that walk through the door, instead of looking at the complex system that is our body as a whole and determining what functional movements we have difficulty with. There is huge variation in movement strategies in our population, and it's unlikely that a test focused on slight variability from a "normal measurement" will have much relevance on treating injury. If your shoulder blade sticks out when you move it, but you can still do everything you need to with it, it moves just as far and as coordinated as the opposite side, and you have no pain, should we be labeling that as something that is sick??
Unsurprisingly, the study found was that there were no correlation to positive results with the SDT test when looking at raising the arm forward or out to the side. This means that a person with a positive result may have no pain at all, and a person with a negative result may have significant symptoms.
But my favorite part of the study was the difference between the examiner who knew if the patient had pain, and the one that didn't know. Simply being aware that the person was in pain caused the examiner to report a positive test 12% more often! So 1 in every 8 people that got tested now have a diagnosis based only on the fact that they said their shoulder was hurting.
Hopefully, study results like these will continue to steer the treatment of musculoskeletal issues towards testing that screens the ability of the individual to perform normal, functional movements with their entire body and compares the right and left differences. Fixing these issues typically results in much better outcomes and reduces potential bias based on the presence of symptoms.
- Observational Scapular Dyskinesis: Known-Groups Validity in Patients With and Without Shoulder Pain. Plummer et al. Journal of Orthopedic and Sports Physical Therapy. Vol 47 Issue 8, Aug 2017.