(See Attached) EE loading powder truck with 50 lb. bags of ANFO. EE stated he had aggravated his lower back and needed to go home and lay down. EE RTW 7/3 and worked full shift. We did not work on 7/4. EE came in 7/5 prepared his truck and started work. At 7:30 a.m. EE came to my office and stated he would make a doctor's appt. because his back was still painful.