Changeling a punch plate on the second deck of scalping screen. EE stated he felt a pull in his lower back. Declined med attention at this time. Called supervisor at 5:30pm on 10/31/11 and stated his back was stiff and sore, but he would wait until morning and see how it felt. Called supervisor at 5:30 am on 11/1/11 and requested to see a doctor because his back still hurt.