hurt my back doing situps!?

You did situps on the concrete. Hehe, there is your answer. You should be fine! It's probably just a little sore, swollen. Take a nice bath, get someone to give you a back rub. If nothing is hurting yu when you are flexing or bending then obviously nothing is pulled, or wrong with your back. You'll be fine! :)

And I give you a strong, virtual handshake for enlisting! Good luck

whats up superb Avitar! right it somewhat is instructions on a thank you to do sit down united statesprecise that can assist you you paintings this out ok sit down-united statesought to be executed while you lie on your decrease back along with your knees bent adequate for the soles of your ft to the touch the floor. place the two palms on your chest and slowly strengthen your head off the floor. strengthen your shoulders approximately one foot and then decrease them to the floor. try this slowly ten circumstances, relax some seconds and then do 2 extra instruments of ten. i think of in case you are trying this you may see the diversities on your neck to boot as your abs good success!