Levator Scapula and Shoulder Impingement
When a client comes in with a diagnosis of shoulder impingement, it really just labels an injury. That is, a soft-tissue structure (tendon or bursa) is being compressed between two unyielding structures (bones or ligament). The diagnosis does not tell us what is causing this compression.
Often, the the cause of a shoulder impingement is coming from inadequate movement of the scapula, from a combination of tightness and weakness in key muscles attaching to it.
For proper shoulder flexion or abduction, the scapula must be able to upwardly rotate, so the inferior angle points away from the body and abduct away from the vertebral spine. In fact, once you raise the arm to 90 degrees, most additional shoulder abduction occurs through abduction and rotation of the scapula.
Try this and see: Abduct one arm to 90 degrees (straight out at your side) and with your other hand, reach across the front of your body to feel the ribs just below your armpit. Now abduct your arm above your head. You should feel the scapula abducting and rotating into your hand.
When looking at impaired movement, we should naturally look to the muscle(s) that perform the opposite movement as a potential source of the problem. The muscle that performs downward rotation and adduction? The levator scapula.
The levator scapula functions to elevate and downward rotate the scapula by exerting an upward pull on the medial side of the superior angle of the scapula. This muscle is often short and tight from various causes, such as: general tension, sitting in front of a computer, or carrying a purse the size of a duffel bag. When tight, the levator scapula will provide resistance to the normal outward rotation and abduction of the scapula during shoulder flexion or abduction, limiting the ROM. Since our bodies are great at compensation, the glenohumeral joint will try to make up the missing ROM to allow a full flexion or abduction. This can cause compression of the supraspinatus tendon (or other structures) under the acromion leading to impingement.
A quick way to see if the levator scapula is tight is to simply look at the client from the back. If the shoulders appear hunched, or one side is higher than the other, the levator most likely needs to be released. For a more thorough view, you need to assess the shoulder in motion.
By releasing the levator scapula with massage and stretching, it can improve the ability of the scapula to rotate and abduct, leading to both improved shoulder ROM and decreased stress on the glenohumeral joint for movement.