Stepping Carefully—Avoiding Little Slips and Big Stumbles!
By Andréanne Labrecque, P.Eng.
Did you know that in 2022, falls were responsible for 7,189 deaths among Canadians aged 65 and older. Among children, 12% of fall-related injuries involved falling on or from stairs [1] . Falls are also a common workplace hazard. Each year, approximately 20 percent of workplace injuries in B.C. are related to slips, trips, and falls [2] . Regardless of the setting, these incidents can lead to insurance claims. Let’s explore how forensic experts investigate such cases.
But first, let’s delve into how we walk and how slips, trips, and falls occur.
Human ambulation is made up of several small cyclic movements that can be broken down into phases: the stance phase and the swing phase. A human step begins with the initial contact of the heel against the ground and continues with the stance phase. This is followed by the swing phase (without ground contact).
This is followed by the swing phase (without ground contact). The stance phase accounts for 60% of the walking cycle, while the swing phase represents 40%, as shown in Figure 1.
Figure 1 : Phases of the normal gait cycle[3]
It is, in fact, surprising that we don’t fall more often! Walking is essentially an exercise in balance. Each step prevents a fall as our centre of mass moves over the support leg’s balance point.
Our brain also anticipates movement, activating the appropriate muscles in preparation for the next phase. However, this same anticipation makes us vulnerable to slips and trips, as unexpected obstacles are not properly processed by the brain, leading to instability.
Definitions
Let’s define and distinguish a few terms related to falls.
A slip occurs when the foot (or shoe) loses traction against the floor surface, causing a loss of balance.
A trip results from a loss of balance when the foot’s movement is interrupted by an obstacle or an unexpected event.
A fall occurs when a person descends to the ground or a lower level, often unintentionally or accidentally, and can be the result of a slip or trip, when the person was unable to regain balance.
What are the most common causes of slips?
- Icy patches;
- Wet surfaces or floors;
- Surface contamination by substances such as dust, powder, granules, lint, etc.;
- Polished floors or freshly waxed surfaces;
- Sloped floors.
And what are the most common causes of trips?
- Changes in elevation, such as unmarked steps or ramps;
- Irregular walking surfaces (holes or raised areas).
Stairs are often involved in fall incidents. Sometimes, the problem is damaged steps, uneven risers, irregular treads or nosings (Figure 2). Poor lighting conditions can also play a role.
Figure 2 : Terminology of the various parts of a staircase
Regulations
The National Building Code specifies several requirements for stair dimensions. Each step must be of a uniform size, and there are minimum and maximum rise and run dimensions. In some cases, the edges of steps and the beginning and end of ramps must be marked with a contrasting colour or pattern.
There are also requirements for step surfaces, some of which must be slip-resistant. The Code also includes guidelines on the number, height, and location of handrails.
Other causes of slips, trips and falls are related to indoor floor surfaces, such as uneven surfaces, poor maintenance, loose floor coverings, or unsecured rugs and carpets. Some architectural finishes can also become slippery when wet.
Techniques and Equipment
Special techniques and equipment are sometimes needed to investigate slips, trips and falls. The first step is to collect data and take various measurements on site. These will help to determine whether dimensions comply with Code requirements and provide a clear picture of the site layout.
For example, a lux meter (Figure 3) can be used to measure light intensity. This device provides a reading in lux. For emergency staircases, the Code generally requires a brightness level of 50 lux.
Figure 3 : Example of a lux meter
For floor surface characteristics, devices such as tribometers measure the coefficient of friction to determine whether a surface is considered slip-resistant.
Figure 4 shows a tribometer that replicates the movement of a heel during a step. The foot of the device, mounted on a mechanical arm, is propelled by a CO2 cartridge which drives the piston. This ensures constant speed and pressure on the foot. A ball joint between the foot and the piston allows movement at different angles.
The operator adjusts the angle of the incidence of the foot until it slides against the surface. The angle at which sliding occurs provides a value for the coefficient of friction. Tests can be performed in wet or dry conditions (by applying a solution to the surface).
Figure 4 : English XL tribometer
Required Information
When dealing with a fall-related loss, it is essential to obtain as much detailed information as possible about the circumstances and location of the incident. This information can be obtained from the fall victim or from witnesses present at the time. If there are surveillance cameras nearby, secure copies of the footage as soon as possible.
Take photographs of the location and the surrounding area immediately after the incident, as conditions can change quickly. If available, a medical report detailing the injury related to the fall and any pre-existing conditions of the claimant can be valuable.
Whatever questions you may have about fall-related incidents, a forensic investigator such as one of our experts at CEP Forensic can provide answers and guide you in managing the claim associated with the event.