What is shoulder impingement?
When the muscles of our rotator cuff become subjected to repeated pinching in between the rounded head of the humerus bone and the acromion process (a bony prominence from the shoulder blade that forms a roof over top of the ball and socket joint) shoulder impingement is occurring. This pinching may only be a discomfort or may not even produce pain at first, but with repetition, our rotator cuff muscles will become inflamed. This repetitive pinching of your rotator cuff can gradually lead to small or even large tears of your rotator cuff muscles.
Why does impingement occur?
Factors contributing to this condition:
- Repetitive and/or prolonged overhead movements can place the shoulder in a position where it is more likely to be impinged.
- Swimming
- Hanging holiday decorations
- Painting walls or ceilings
- Picking up your kids
- Posture
- posture impacts the positioning of your shoulder blade and therefore the positioning of the bony roof of the shoulder. If the bony roof hangs forward over the shoulder more than it should, any upward reaching position would be more likely to produce impingement.
- The anatomy of one’s shoulder can also affect the likelihood of impingement.
- People with more rounded acromion processes and some have bone spurs or other degenerative changes that can make impingement and rotator cuff muscle irritation more likely.
- Strength and control of the rotator cuff muscles.
- The role of the rotator cuff muscles is to not only help move the shoulder in various directions, but also to help provide stability of the ball and socket joint. The socket part of the joint is actually fairly shallow. So as the arm is reaching upward, if the rotator cuff does not have adequate strength or control, the ball end of the arm can slip upward resulting in impingement.
- Weak muscles around the shoulder blade
- If the muscles around the shoulder blade are weak or do not coordinate well with the rest of the shoulder, then you are going to end up with an unstable foundation on which the rotator cuff muscles work.
Physical therapy can help!
The good news is that physical therapy can help to avoid and treat shoulder impingement issues. A physical therapist is trained to be able to determine if you are experiencing impingement related shoulder pain and to assess posture, flexibility, muscle strength, stability, coordination, joint mobility, and muscle tone in order to determine which factors are contributing to this impingement.
They can then help teach you how to address the underlying issues contributing to your pain in order to help you be able to move and use your arm without further irritation of the rotator cuff muscles.
By: Rachel Herrmann, PT, DPT
