Shoulder pain while in aero position?

Are your shoulders riding up towards your ears?  I learned here to keep the shoulders down away from the ears.  And in everyday life think about walking around "shoving you shoulder blades into your back pockets"

Its made my debilitating pain go away.

Oh and ride more!

I also used to have pain in my shoulders when I was in aero position (yes even with a fitting).  So I played with positioning of the aero pads and extensions until I made a discovery.  My aero bar extensions were too far apart relative to my elbow pads.  This was causing a slight outward rotation of my shoulders and putting me an an awkward position that went beyond my comfortable limits of flexibility.  It didn't show up in fitting and on short rides, but after some time on the road the pain would get worse.

The best way I can explain it is this...  while sitting at your desk, lean forward and rest your elbows on the desk as if you are in aero position on your bike.  Space your elbows at a relatively comfortable position similar to the spacing of your bike setup.  Now move your hands apart so that your forearms are nearly parallel, or maybe angled in very slightly.  That's probably typical of most aero bar setups.  This is how mine was set up and where I felt pain.  Now, while keeping your elbows spaced exactly where they are, move your hands closer together, so that they are nearly touching.  (your forearms should now form a triangle with your chest.  This position suddenly relieved that stress in my shoulders and was MUCH more comfortable. 

Once I discovered this, now the problem for me was that my elbow pads were attached to the aero extensions, so there was no way to move the hand position closer without also moving my elbow pads closer.  I'm wide in the shoulders so my natural and comfortable position is to have my elbows spaced wider.  So I switched my bars for something that had a fixed aero extension spacing that was close together, and still allowed me to space the elbow rests further apart.  Now I'm very comfy with no more shoulder pain. 

There's never one perfect answer that works for everyone.  This worked for me.  ?I don't know if your situation is similar, but if it is, I hope this was helpful.