Nick,

You can easily modify your movements to reduce or eliminate the jarring. Do not jump down from the truck. Use a ramp. Do not lift with a jerking motion. A chiropractor or physical therapist can teach you how to set yourself before doing a lift. I routinely lifted 100 to 150 pound cast iron sinks off the floor into a hole in the kitchen counter without a problem. I learned to stand in front of the load, square myself to the load and bend down to lift the load.

I have plenty of opportunity to jump down from truck deck levels but do not. Instead, I step down. I have a 16,000 pound crawler loader where the last step is 24 inches. I am even careful to step down from that low height. My brain and neck appreciates the extra care.

A request of your boss to accommodate an easier step down is in line with OSHA standards.