Why do I get horrible muscle spasms (?) below my sternum when I bend or twist?

[IamKW]

It’s been about a year of this, and it affects how I choose to move. I asked my ob/gyn if it was diastasis recti or a hernia, so she sent me for a CT. Absolutely everything looked fine, per the radiologist’s report. It’s really painful! I have to raise my arms up and massage the area between the top of my ribs for several minutes before it subsides. Does anyone know what this is?