Failures in ergonomics practice rarely arise from singular, catastrophic deficiencies. More commonly, they reflect subtle but consequential misalignments between human capability, task demands, and the environments in which activities are performed. This presentation draws on lessons learned through a series of ergonomics investigations undertaken while providing expert opinion in litigated matters involving fatalities or serious injuries. These matters, examined retrospectively and under conditions of scrutiny, provide a distinctive lens on how and why systems fail to achieve an effective fit with the people who use them.
Across multiple cases involving elements of the built environment, access systems, and manual task design, consistent patterns emerge. These include reliance on assumptions about user behaviour that do not hold in practice; insufficient allowance for variability in users, conditions, and contexts of use; and changes over time—such as wear, contamination, or modification—that alter system performance in ways not anticipated at the design stage. Importantly, these issues are typically not attributable to an absence of guidance or standards, but rather to a disconnect between design intent and actual use.
The approach outlined integrates physical evidence, site inspection, task reconstruction, and reference to relevant technical materials to identify the mechanisms by which misfit arises. From this, a set of transferable insights is derived, focusing on recognising where design assumptions commonly break down, identifying latent conditions that increase risk, and emphasising the importance of designing for everyday use rather than idealised conditions.
The purpose of the presentation is not to address questions of liability, but to translate experience gained in the investigation of serious injury events into practical guidance for ergonomics practitioners. In doing so, it illustrates how insights developed under forensic conditions can inform more robust, defensible, and effective ergonomics practice, consistent with achieving a better fit between people, systems, and environments.