In the beginning, to ensure a reliable, cost effective investigation, s/he should do no more than capture the physical scene where the accident happened – and do this quickly before conditions change.

An expert does this by carrying out as many as 13 different tasks at or near the specific location of the accident indoors or outdoors.

For example, if the accident occurred indoors:

1. Video and photograph the site as seen by the victim and as seen from a drone,
2. Measure the slope of floors and ramps, and the width and rise of stairs
3. Record the nature and surface condition of the materials forming these features,
4. Measure the location and construction of handrails and guardrails,
5. Record the presence of debris, liquids or dust at the location of the slip, trip or fall accident, and,
6. If the shoe or boot is available, examine and record it’s construction

Carrying out these tasks and others is basically an elaborate visual site assessment. Nor is it unlike a topographic survey outdoors that might be done by a provincial land surveyor.

Use the data from this work to show the scene in accurate drawings and photographs. Make, what we call in engineering, as-built or as-constructed drawings. These can also be rendered today with the software that is available in very impressive 2D and 3D formats.

Components of accidents

The expert should refrain initially doing more because these types of accidents have several components. The relevance of each of these to one another and to the accident can’t be evaluated – and the significant one(s) focused on – till the physical setting is nailed down. Trying to do otherwise is expensive – a waste of time and money.

A list of the components of the slipping- or tripping-while-walking hazard looks like the following: (Refs 1, 2 and 3)

1. Person
2. Activity
3. Floor covering (walking or working surface)
4. Lubricant
5. Footwear (slider)
6. Ambient and environment parameters

Each component contains a lot of parameters that are far too numerous to list here. A few are noted in the following:

The condition of the person involved can be crucial. For instance, gender, age, experience and personal situation help determine how much caution a person uses.

Some activities require more foot traction than others. For instance, walking normally in a straight line is least demanding. Walking fast, turning or stopping is more risky.

The floor covering is likely to be different for walking surfaces compared to working. The properties of the floor are important in traction. These are determined by no less than two and half dozen parameters.

A lubricant can be any substance between the walkway and the footwear that reduces slip resistance. Water is just one. And it can get on the floor in different ways both inside and out. For instance, at drinking fountains and sinks indoors and by lawn sprinklers outdoors.

An accident occurs when there’s insufficient traction between footwear and the walking or working surface. A couple of dozen properties characterize the contact between the footwear and the floor in determining traction. Material properties and tread are of paramount importance.

(Ice cleats on boots won’t necessarily save you. I found this out this morning while cleaning wet snow from the timber stairs up to my deck. I slipped on the stairs but can run on ice with these cleated boots. So why the slip? February 2, 2021)

For sure, the environment influences the slipping-while-walking-hazard. Parameters like weather in general – sunshine, rain, snow, wind and humidity. But also lighting, surface slope, handrails, and room equipment and furniture.

***

The engineering and scientific literature has identified numerous factors in the slip, trip and fall hazard. (Refs 1, 2 and 3) Legal and claim settlement practice manuals have identified others relevant to resolving disputes arising from these accidents. (Ref. 4)

The engineering expert must focus on the big picture initially – the setting of the accident – and do this quickly. And in the process identify the relevant components and parameters for more detailed investigation. This is the only way forward in reliably and cost-effectively determining the cause of slip, trip and fall accidents.

References

1. Sebald, Jens, System oriented concept for testing and assessment of the slip resistance of safety, protective and occupational footwear, Pro Business Gmbh, Berlin 2009
2. Sotter, George, P.E., Ph.D., Stop Slip and Fall Accidents!, Sotter Engineering Corporation, California, 2014
3. Di Pilla, Steven, Slip, Trip and Fall Prevention, A Practical Handbook, 2nd edition 2010 ESIS, Inc. CRC Press, Boca Raton
4. Turnbow E, Charles, Slip and Fall Practice 2nd edition, Revision 17 2012 James Publishing, Inc.

(Posted by Eric E. Jorden, M.Sc., P.Eng. Consulting Professional Engineer, Forensic Engineer, Geotechnology Ltd., Halifax, Nova Scotia, Canada February 5, 2021 ejorden@eastlink.ca)