The effect of postural changes on slip and fall accidents
"Injury in U.S.A" identified the role of falls in producing injury throughout all segments of the nation. The economic and social costs arising from falls have been established in numerous sources, both nationally and from the international literature. "Injury in U.S.A." also indicated the potential role of epidemiology in identifying the significant features of falls, the need for a basic understanding of the energy exchange mechanism involved and the subsequent rehabilitation processes required. It appears unlikely that any other major cause of injury has an etiology so little researched and consequently, so little understood, which in turn has prevented the development of an intervention strategy or a scientifically based control technology of falls. Also, tribometric research on rubber-like materials confirms the need for dynamic data from human gait and slipping. So far, unfortunately, this problem has been underestimated by many investigators of slipping accidents, who did not consider slips and falls to be complicated phenomena from both tribological and biomechanical aspects. In most walking the heel slides upon heel strike. Usually, the sliding motions are unnoticed by the subject and occur even without lubricant. Under certain circumstances, these microslips develop into uncontrolled slides which in turn lead to the most common type of fall. However, a larger number of slips are clearly stopped at a distance of a few centimeters or less. This study reports on the relationship between foot attitude, two-dimensional slip patterns, body segment motion, the forces involved through the whole of the slip:stop cycle for a two walking speeds and two levels of slipperiness design.