Related Experiment Video
Updated: Mar 11, 2026

The Ladder Rung Walking Task: A Scoring System and its Practical Application.
Published on: June 12, 2009
Evaluation of a "walk-through" ladder top design during ladder-roof transitioning tasks
P Simeonov1, H Hsiao1, J Powers1
1Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA.
Abstract:
This study evaluated the effect of an extension ladder "walk-through" top design on kinetic and kinematic behaviors and the outward destabilizing forces induced on the ladder during transitioning at elevation. Thirty-two male participants performed stepping tasks between a ladder top and a roof at simulated elevation in a surround-screen virtual-reality system. The experimental conditions included a "walk-through" and a standard ladder top section supported on flat and sloped roof surfaces. Three force platforms were placed under the ladder section and in the roof to measure propulsion forces during transitions. A motion measurement system was used to record trunk kinematics. The frictional demand at the virtual ladder base was also calculated. The results indicate that under optimal ladder setup (angle 75.5 °), the frictional demand at the ladder base remains relatively small for all experimental conditions. Also, the "walk through" ladder top eased the ladder-to-roof transitions but not the roof-to-ladder transitions.
Related Concept Videos
Design Example: Traverse Angle Computations
Design Example: Managing Concrete Workability
Simpson's Rule II
Design Consideration
The factor of safety is another key...
Design Example: Maintaining Level of an Embankment
Method of Sections: Problem Solving I

