Slips, trips, and falls

Abstract

Slips and trips started when primates evolved to take an upright stance and stood on two legs instead of four. This change meant the center of gravity for the primates instantly became higher. It also meant the level of support lessened creating an inherently unstable situation. Humans are the most likely animal to trip or slip because our world is full of distractions and we may not "see" small projections in our walking paths. The early paths humans took probably followed animal trails which were made of earth and rock. This type of surface is self-repairing. That is, earth/dirt is quite malleable and easily made flat with foot traffic. It is also re-routable in that if a path becomes blocked, a new path can be formed. For millennia, animals have dealt with blocked paths by finding another route which they then similarly trod down. The establishments of these new paths were aided by nature: rain turned them into quagmires and heat then dried them up to create new more flattened surfaces. In modern times, pedestrians in most urban environments generally walk down concrete and bitumen footpaths. The footpaths are a requirement for urban living and are more durable than a dirt path. People walk at a speed according to predictable terrain. If there is an acute change in the level of the walkway that is not readily observable and is out of step with the preceding pattern, the risk of a trip increases. If there is an acute change in the friction on the surface of the walkway that is not readily discernible, the risk of a slip on the surface increases.