And now- my opinion on the Grasshoppers problem- which I hope has just gone away by now. If you were tired or overdid ab work, the hip flexors, tendons right at the front of the hip that attach the quadriceps to the ilia, take over the load. A lot of ab exercises aren't very ab because they involve the hip flexors more than the abs. The one you were doing will do that. You probably strained one of them, and a few days of rest and ibuprofen will fix it up. Stinky Ben Gay is good too. And heat.
Maybe you should change your ab work for a while and find exercises that just burn up the gut mucles with no hip flexor involvment. Really good ab work is SO onerous, but worth it.

Lizzie