Everyone has had at least one fall in their lives, whether during childhood when learning how to walk or more occasionally during adult life. We know that we have developed avoidance and protective reactions which make it possible to reduce their consequences in most instances.

On the scientific plane, one of the main difficulties to be resolved is that the very concept of what constitutes a fall remains vague because it covers many different situations.

In 1987, the Kellog International Working Group on the prevention of falls among the elderly defined falls as being 'an involuntary movement towards the ground or a lower level, which does not occur as a consequence of being violently thrown off balance, losing consciousness or the sudden appearance of paralysis following a vascular accident or an epileptic seizure.'

This definition has been used in various research projects and has sometimes been extended to cover falls caused by dizziness, syncopes and the other consequences of epileptic seizures and cardiovascular accidents, which can all lead to a loss of consciousness and injuries.

For over 20 years, a lot of research has been carried out across the world in an attempt to develop a reliable device to detect falls among seniors.