Second only to automobile accidents, falls are the leading cause of injury and deaths. Of these, accidents due to slipping or tripping form a large proportion. Slips  and trips occur on floors, streets, walkways, stairs, etc. Although both slips and trips result in falls, they are otherwise quite different. A slip is associated with insufficient resistance between a foot and the walking surface, while a trip involves much more resistance than the victim had anticipated. A third type of fall results from a loss of balance. This can occur when one expects a surface to provide support, but it does not, such as while descending a staircase with an unanticipated long rise height step.