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Function of the Shoulder Blades

A solid foundation is an important feature of any structure. When the foundation is faulty, it causes problems with the rest of the related areas. If one part of your home’s foundation begins to sink, you might find cracks in the walls running all the way to the top of your house. A properly functioning foundation is the main goal of core strengthening. Taking a step beyond the core, the shoulder blade provides the foundation for proper shoulder joint function and shoulder health.

Problems with shoulder pain, especially chronic pain caused by overuse, can often be traced to a complication with shoulder blade mobility. Possible problems with the shoulder blade can include:

  • Not enough movement of the shoulder blade in the correct directions (hypomobility).
  • Too much movement of the shoulder blade or lack of strength to hold the shoulder blade still when the arm moves or lifts something (hypermobility).
  • Improper starting position of the shoulder blade (static or postural impairment).

Each issue could potentially cause problems in the shoulder joint itself (the ball and socket joint between the arm bone and the shoulder blade). The entire shoulder complex is made up of the arm, the shoulder blade and the collarbone. It is only rigidly attached to the body (at the sternum) at the end of the collarbone on the top of the chest. The shoulder blade is attached to the upper back and neck through muscles that are flexible and vary in strength and endurance. The good news is that this arrangement allows for a wide mobility range for the arm. The bad news is that muscles are responsible for most of the alignment and function of the shoulder. Muscles can become tired, overstretched, tight and painful.

Since the shoulder blade shares muscles with the upper back and neck, pain in these areas can be caused by issues with the shoulder blade, not just the spine itself. So, exactly what about the shoulder blade position and movement makes it so important? If the shoulder blade is out of position or does not move properly, muscles that are moving the neck or arm can end up overstretched or overworked in an attempt to overcompensate. For example, if the shoulder blade is too mobile, the rotator cuff will need to work harder to lift the arm since both ends of the muscle are moving. For a muscle to work at its best, one end needs to be held still or stable. Think of trying to push something while standing on ice. You cannot get much “oomph” behind your push because your feet are not on a firm foundation. If the rotator cuff is overworked, it is at a greater risk of injury. Likewise, if the shoulder blade is not mobile enough, the space underneath the end of the shoulder blade and above the arm bone (subacromial space) becomes limited as the arm moves overhead. If the shoulder blade cannot move out of the way to maintain the space, the arm bone and the underside of the shoulder blade make contact with each other. Two problems result from this: First, the rotator cuff tendons live in the subacromial space. Contact of the bones pinches and injures the rotator cuff tendons. Secondly, when the bones contact each other, bone spurs and arthritis are likely to occur.

Obviously, the shoulder blade plays an extremely important role in the proper function of the shoulder, neck and upper back. To fend off pain and injury, or to prevent problems, the function should be either restored or maintained depending on the condition from which you are starting. To improve your shoulder function, follow the shoulder exercises we have provided. As always, if you have an injury or pain that limits your movement or causes severe pain see your medical provider or therapist for an individualized diagnosis and treatment plan.