This paper presents research concerning a specific, but common, hazard associated with excessive stepladder twist flexibility. Serious injury can result when, unbeknownst to a climber, only three of the ladder's four legs are in contact with the ground and there is a weight shift that causes the raised leg to suddenly impact the ground and dislodge the user. Test and analysis results are presented which show subtle causes of this hazard, as well as design improvements to reduce the possibility of their occurrence. The adequacy of existing stepladder safety standards to protect users from this type of accident is also questioned.
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