THE WELDER WAS CARRYING AN 8 LB BEARING SLEEVE. HE TURNED SIDEWAYS TO ENTER A DOORWAY AND HE STEPPED DOWN AT THE SAME TIME (APPROX. 16"") TO THE NEXT LEVEL. HE THEN FELT A SHARP PAIN IN HIS LOW ER BACK. HE HAS RECEIVED THREE CHIROPRACTIC TREATMENTS SINCE 12-26-01. NO RESTRICTIONS.