Falls are a leading cause of truck driver injuries
The safety issue arises when jumping from the cab, top step, fifth wheel area or a trailer deck area. This type of jump increases your chance of injury by impacting your joints, lower back and lower limbs.
Another type of jump from a dock level loading door by either a driver or a dock worker can also end in broken bones or other serious injuries, please do not get into this practice it will end in bad results. This is a voice of experience talking on this topic. In one particular case a driver had the truck step break and went to the pavement, knocked unconscious for an unknown amount of time, was found by a fellow worker. Over a year off from work was a result of the head and body injuries sustained from the fall.
The toolbox talk today is based around this type of jumping and the impact on your body. This is an excellent toolbox talk from WorkSafe BC and the importance to Always Maintain 3 Points of Contact at all times in and out of trucks and decks. A reminder though this tool box talk is from British Columbia, this type of fall is the leading cause of injury in Canada.
Here is the pdf of the three point of contact for your toolbox talk .