Ladder falls remain one of the most dangerous and common events that workers experience every year. As such, much has been done to ensure that ladders are designed properly and that workers know how to use them safely. For instance, workers are told to always have three points of contact when climbing, to never carry tools up a ladder and to pay attention to weight limits.

All of these things can and do help, but safety may start long before anyone actually gets on a ladder. Workers need to know how to set it up and where to do so, as placement of the ladder itself changes just how safe that ladder is.

For instance, when working near doors, workers always want to make sure that the door opens away from the ladder. This is true even when they don’t expect anyone to use the door. If someone comes through unexpectedly, the door can strike the bottom of the ladder and knock the worker to the ground.

Workers also need to ensure that the surface they put the ladder on is flat, stable and not too slick for the ladder’s feet. Even missing one of these signs — setting the ladder on loose dirt that can shift under weight, for instance — can be enough that the ladder will move notably once in use. It may have looked safe initially, but it becomes much less safe at the critical moment when the worker ascends.

Even setting a ladder up safely does not guarantee that an injury will not take place. Those who get hurt on the job must know what options they have.