Atlas Shrugged
Shrugging during an upper body exercise is a common compensation that is recognized by most movement specialists as a weakness issue. Typically associated with rotator cuff deficits, the shrugging motion is created to elevate the arm when there is a significant tear in the cuff. That compensation is also noted when there is no known rotator cuff pathology, however the same thought process is applied and may be underappreciating the complexity of the issue at hand.
An attempt to raise your arm overhead with the compensatory shrug is a movement strategy. There may be pathology present, but barring any tissue harm, it is the body’s way of achieving a desired action. If we cannot effectively compress the shoulder joint space, one option is to move that action to the spine. We can push it down, compress multiple vertebrae in the neck and upper back which gets us some version of the movement we are seeking. It may not be the optimal solution, but it can get the job done.
Limiting this behavior tends to be desirable as it too, has tradeoffs. The act of shrugging engages large muscles in the upper back that produce massive forces. Those forces not only aid in lifting the arm, but they also glue it to the spine. Those vertebrae we talked about earlier, they become adhered to one another. This is an incredible strategy to move heavy things or produce tremendous pounds of force. It is not the most useful way to reach something in your kitchen cabinet, or behind your back to put on your belt. Those activities, and ones like them, require greater refinement. The shoulder joint itself needs to move independently of the spine, and the upper arm needs to move independently of the shoulder blade. Achieving this degree of independence requires some muscle be selectively turned down or off, allowing others to participate more fully. That also promotes the more efficient use of connective tissues in the area. Coaching exercises like concentration curls, sled drags, landmine presses or cable rows can all be useful ways to re-establish joint mobility.
Shrugging is a viable strategy at times. It sacrifices the multidimensional nature of joint movement for force production. If the four dimensions of movement are needed for an activity, restoring the ability of tissues to move with respect to one another is paramount. Unlearning old habits, then training new ones might be one of the best ways to do so.
Austin Ulrich, Physical Therapist
