I was prompted in a recent blog to recommend assessing the physical setting of a site first then go to more detailed investigation later, if necessary. (Ref. 1) This cost effective, staged approach works in other fields of engineering investigation, why not for slip, trip and fall accidents?

Use the data gained to identify in a second stage the most important components of the accident and how they relate. Then in a third stage focus the investigation on the parameters characterizing these components, rather than on the many dozens. This approach is reliable and cost effective.

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I was struck again on leafing through the literature on the many factors that could be investigated. I thought, I must make sure readers understand the cost effectiveness of this approach.

One exhaustive European study of the slip resistance of footwear has also been accepted by American firms that design, manufacturer and sell skid testing equipment. (Ref. 2) The study counted the following approximate numbers of parameters/factors for the four main components of an accident that would need to be investigated:

1. Floor covering component: … 34 parameters
2. Lubricant: …………………………….. 28
3. Shoe: ……………………………………… 23
4. Ambient parameters: …………. 22

Other researchers identified more components and fewer parameters but this gives you an idea of the possible magnitude of forensic investigations of slip, trip and fall accidents.

For example, take the shoe component from the above list. The 23 factors can be grouped under:

1. Type of shoe
2. Properties of the shoe material, and,
3. Design of the tread

An investigation of the Type of shoe would determine if the accident victim was wearing a leisure shoe or a work shoe/boot, or if the victim was barefoot.

Investigation of the Properties of the shoe material might look at the type of material, the additives present, the hardness, density, elasticity and strength of the shoe material, whether it was a single or dual layer sole and it’s chemical composition.

Investigating Design of the tread would determine the size and width of the shoe, the geometry and depth of the tread, it’s texture, it’s roughness, the edge finish, the amount of wear and if there were cleats.

This involves a lot of forensic engineering investigation – just of the 23 parameters in the shoe component.

Then add in all the factors associated with the Floor covering – as many as 34 depending on how you count them. And any Lubricants present, about 28 – like rain water in a foyer and cooking oil in a kitchen. And the 22 Ambient parameters, including weather and temperature, the many human factors, the floor gradient and lighting, and the existence or absence of handrails.

This could add up to an exhaustive engineering investigation – if its not done right – and a red light for both experts, litigants and insurers; Beware!

This has come out of one widely accepted study in Europe that is accepted in the U.S. And no question in Canada. I’ve read and seen how other American studies tweak the European work and add a little more to a forensic investigation.

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For sure, some of the many factors I’ve noted above would be covered off quickly after the physical setting of the accident site has been surveyed.

For example, was the victim wearing a recreational shoe or a work boot? Was it raining that day just outside the foyer? Was the victim walking or running? Were there handrails on the stairs, and did the ratio of step width to riser conform to the standard of practice for stair design?

Summary

I believe, considering the dozens of factors involved, (Ref. 2) – and hopefully you have a better understanding of this from the above – that slip, trip and fall accidents are prime candidates for peer review of the expert’s forensic investigation. (Refs 3, 4 and 5) Particularly if the investigation involves additional stages after initially assessing the physical setting of the accident site. (Ref. 1) Peer review is cast-in-stone in science and should be in applied science, like the investigation of slip, trip and fall accidents.

References

1. What does an engineering expert do at the scene of slip, trip and fall accidents? Posted February 5, 2021
2. Sebald, Jens, System oriented concept for testing and assessment of the slip resistance of safety, protective and occupational footwear, Pro Business Gmbh, Berlin 2009
3. Is there an argument for a peer review of a peer review? Posted January 11, 2020. A good read.
4. Ridding peer review of potential bias. Posted December 30, 2019. Another good read.
5. A Bundle of Blogs: On the need for peer review in forensic engineering and expert services. Posted November 29, 2019

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada February 18, 2021 ejorden@eastlink.ca)