The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
I have some constant tingling/numbness in my left hand which I’m pretty sure is caused by my tight pec minor on that side. (Might be tight bicep problem too) Looking at the anatomy at http://www.zygotebody.com/ it looks like the nerves run under the pec minor. You might be compressing the nerves. Try coming at it obliquely by laying on your side or leaning into a door jam with the Gemini.