I was right. I pulled something on the Conductive Row. Or maybe I didn't stretch enough. Or the right way. Here is the stretch I didn't do, but probably should have:
This site has ten basic stretches to do after your workout. Had I read these before trying the conductive row, I may not be as achy now. Live and learn, I guess.And according to www.active.com, I should've warmed up my back before attempting to use those muscles. Arm circles are a good warm-up.
Hopefully my pain is your gain. Warm-up before exercise, do the correct stretches afterward.