More about how the shoulder blade works with the shoulder and how bad shoulder girdle strength can cause shoulder impingement. The image and movie clip below show shoulder blade elevation, with the actress in the video showing LESS elevation and upward rotation on the left than the right.
The space between the ball (humeral head) and the shelf above (acromium) which sits on the shoulder blade is where impingement of one or two of the rotator cuff tendons happens (supraspinatus or infrapinatus).
Here is an image of a normal shoulder and one with impingement:
If the shoulder blade is hanging low (like the one on the left in the video) the space for the tendon is a lot smaller. So doing shoulder blade strengthening exercises to elevate the shoulder blades will help with shoulder blade pain itself.
The serratus anterior muscle is THE core muscle of the shoulder and arm. It lifts and supports the shoulder blade and arm from below and underneath. This muscle is key to good posture.
During the day at work, school, and chores and sports, to remind the serratus anterior to contract and help you have good posture and reduce pain, here is a video:
If you are interested in research on the serratus anterior and shoulder pain, here is a link to an article: http://www.aott.org.tr/index.php/aott/article/view/4897/2610
Do you have neck pain, especially from sitting for a long time? I recently took a long flight and after a while my neck and upper shoulders started to become stiff. What exercises help that?
Of course stretching your neck and shoulders helps like this:
BUT there is another tight muscle that strains your neck and it is, SURPRISE, the latissimus muscle! It is located below the shoulder blades and when tight, pulls the shoulder blades down straining the muscles on top of the shoulder blade which connect to the neck such as the upper trapezius, levator scapulae and rhomboids. Here is a picture:
Here it is: the fix for shoulder blade/scapular weakness on one side that makes progressing your P90X workout, or any upper body workout for that matter, harder.
If you follow the above links you will see how to strengthening one-sided shoulder girdle problems. When the shoulder girdle is weak, it can cause winging. If it is just a little weak, like it is with this lady, then you may have headaches, because of the stretch to the upper trapezius. You might also develop rotator cuff impingement due to this problem.
How do you develop shoulder blade weakness? Usually it hppens because you might have an arm injury, which can make your muscle weak as they try to protect you and stop you from using an injured body part. Other causes can be prolonged computer use in which your arms and shoulder are held in the shoulder forward position.