EE was cleaning rock off EE's trailer with a broom after being loaded with 2-4"" rock by a loader. EE was unable to reach all of the rock with the broom so EE climbed up on the trailer finish cleaning off. As EE was getting down, EE jumped the 3 1/2 feet to the ground and felt a pop in EE's lower leg, resulting in a trimalleolar fracture of the right ankle.