Ergonomic design interventions--a case study involving portable ladders.

Portable ladders are one of the most ancient tools conceived by man. They remain ubiquitous and indispensable even today. It is interesting to note that there is little difference between the makeshift portable ladders used throughout history and some still used today. The design of portable ladders seems to have simply evolved, rather than been subject to formal design process, including ergonomic criteria. An analysis of 277 fatalities associated with ladders was conducted to describe the pattern of ladder fatalities and identify and assess ergonomic design controls. All ladder fatalities analysed were found to contain multiple human, equipment (ladder) and environmental causative factors. It is hypothesized that significant gains with regard to reducing future fatalities can be achieved by applying ergonomic design principles to ladders to accommodate predictable and undesirable human behaviour. Without effective future change, the only prediction that can be made is that the pattern of ladder fatalities will simply continue.