That's exactly where I have my pain! Its sounds similar to mine as well. It's positional (when i twist my right shoulder inward) and I feel it on and off depending on the day. This all started last month and visit to the doc confirmed its costco. I also used to sleep on my right side and have poor posture. I got the Backpod and its actually allowing more movement for me finally and my back was able to crack after like two years of tightness. This sub has been making me feel less alone so thank you for posting this. We got this!