TRUCK DRIVER WAS DOING PRE-OP CHECK AT START OF SHIFT ON #219 PRO-TRUCK. HE WAS DESCENDING THE ENGINE ACCESS LADDER WHEN HE SLIPPED. HE LANDED ON HIS FEET, FALLING ONLY ABOUT 1 FOOT. HE EXPERI ENCED A LOW BACK STRAIN THAT LATER RESULTED IN LOST TIME. WE RECENTLY RECEIVED MEDICAL CONFIRMATION OF THIS INJURY.