On Improving Set-Up Angle Accuracy for Extension Ladders

Abstract

The set-up angle for a straight extension ladder can influence the likelihood that the ladder will either slip out from the base or tip over at the top. The present study examined different methods of determining the set-up angle for ladders. Sixty-eight lay persons set up an extension ladder at three different heights (3.0, 4.3, and 5.2 meters), each using one of six methods—Basic, Stand-Reach, “L” Sticker, 75.5 degrees, 4-to-1, or a Bubble level. Results demonstrated that the Basic method (where participants were given no specific instructions) produced significantly more shallow set-up angles than any of the other five methods. The Bubble condition (where a bubble-level was provided on the side rail of the ladder) produced performance that was closest to the criterion of 75.5 degrees. All of the other methods produced intermediate set-up angles that were between the Basic and the Bubble conditions. These results indicate that assistive devices can be useful in promoting less-shallow ladder set-up angles.