Despondent Cyclist Laments Failing Erector Spinae Muscles!

Well, I think it's my erector spinae muscles that are aching so much. Something down there hurts quite a bit, and I'm not sure what brought the pain on (sitting at the office?). Part of me thought I should ride on this lovely morning to exercise the offending area, but I opted to drive lest I strain something all the more. Tomorrow, my massage therapist pal will hopefully knead this malady out of existence!