Recommendations for their design and use
Falls brought about by slips, trips, twisted ankles, or missteps are a significant category of accident in the workplace environment. In order to avert the hazards that can result from the use of stairways and floor coverings, the planning process should also focus on user-friendly, biomechanically optimised design and not just purely architectural or technical safety features.
What are the causes?
Accidental falls make up approximately 20 per cent of all accidents each year and are therefore responsible for high costs and long periods of absence from work.
When an accident has happened, an inspection of the stairway or pedestrian area will often find it can be regarded as intact from a technical point of view, it is neither dirty nor damaged, and design and construction regulations have been complied with. Where no obvious defects are detected, there is sometimes a temptation to conclude accidents are attributable to human error, "carelessness", "clumsiness", or a "lack of concentration" for instance.
"Clean and intact" is not the same as "safe"
Apart from causes such as behavioural errors on the part of users, even stairways or pedestrian areas that appear to be in immaculate condition may have serious hidden flaws in their design. Structural parameters such as the dimensions of steps and landings or the characteristics of treads and nosings may be incorrect or surfaces may not be sufficiently slip-resistant. What are known as perceptual conditions (e.g. lighting, the use of colour, markings) may also be poorly adapted to the human motor control system.
Facilitating undisrupted movement rhythms
Walking up stairs is a learned form of rhythmic motion that is adjusted to the specific parameters of each stairway. An automated sequence of movements reduces the amount of mental strain involved in climbing stairs.
The situation is, however, very different if
- riser heights vary over the course of the stairway,
- the nosings are difficult to make out,
- the end of the stairway or start of the landing is not noticed in good time,
- the normal stride length does not match the dimensions of the steps or landings, or
- disruptive variables (such as inappropriate footwear, the carrying of loads, obstacles, objects left on the stairs, or distractions) adversely affect the flow of movements.
If one of these problems is encountered, or even several of them simultaneously, they can cause uncertainties that lead to falls. It is therefore vital to bear in mind that undisrupted movement rhythms and the user-centred design of pedestrian areas are decisive, key variables for the prevention of accidental falls.