The literature over the past several years has demonstrated the direct link between scapular dyskinesias and shoulder dysfunction. For example, if someone lacks Serratus Anterior motor control, it can manifest as the pathoanatomic diagnosis of 'shoulder impingement syndrome.' Good SA strength is essential for normal upward rotation and posterior tipping of the scapula. Clinically when a patient lacks SA motor control, the patient may present with shoulder pain, neck pain, and/or thoracic or rib dysfunction. In this patient scenario, the upper trapezius, scalene muscles, rhomboids, and levator scapulae become dominant and hypertonic. Dominance pattens feed upon themselves until pain or significant dysfunction arises.
How the Patient will Compensate for Scapular Weakness
Since the scapular stabilizers are not functioning properly, the body develops creative compensations to complete specific movements. First, the patient may demonstrate excessive lower thoracic extension. With increased lower thoracic lordosis, the thoracic paraspinals become dominant. Each time the scapular stabilizers attempt to contract, the thoracic spine locks into extension and powers through the movement using the paraspinals. It will appear that the patient is hinging from the thoracolumbar junction. To retrain this pattern, you need to focus on core position. Have the patient find a neutral spine, then work on retraining the specific scapular dyskinesias. Retraining will often need to happen in a gravity eliminated position (sidelying, prone, or AAROM in supine) because these patients do not know how to activate the scapular stabilizers.
A second compensation is excessively using the shoulder external rotators without any scapular stability. This patient will have very dominant Teres Major and Minor muscles and Latissimus Dorsi. A neutral posture for them is retracting the shoulders without any upper thoracic extension. They appear to be in decent postural position, but in reality are lacking proximal/central stability. I often think about this compensation similar to someone who is hamstring dominant. The client appears to have good strength, but they are using prime movers to gain a false sense of stability.
In both scenarios, find neutral torso alignment first. This means engaging the deep Transversus Abdominus activation from a long torso position. From here, work on breathing mechanics, ribs mechanics, and engaging deficient muscles. Make sure the patient is not tipping their lower ribs to the pelvis to find a neutral core!
Check out the video below which demonstrates the 2 common postural compensations.
-Jim Heafner PT, DPT, OCS
OPTIM COMT Instructor