An employee was using a pallet jack to move a container from inside a box truck to a lift gate. The employee set the container on the lift gate. When the lift gate was lowered, the pallet jack and the container shifted, and the container knocked the employee to the ground. His right leg was caught between the lift gate and its support and was broken in three places between the knee and the ankle; his right arm struck the ground and was broken between the elbow and the wrist.