the time of the fall. The second phase of a fall involves a failure of the systems for maintaining upright posture to detect and correct this displacement in time to avoid a fall. This failure is generally due to factors intrinsic to the individual, such as loss of sensory function, impaired central processing, and muscle weakness. The third phase is an impact of the body on environmental surfaces, usually the floor or ground, which results in the transmission of forces to body tissue and organs. The potential for injury is a function of the magnitude and direction of the forces and the susceptibility of tissues and organs to damage. A fourth phase, although not part of a fall, concerns the medical, psychological, and health care sequelae of the fall and attendant injuries. These sequelae effect the degree of damage and disability resulting from the fall. Approaches to preventing falls and their consequences should focus on factors related to each of these phases.
Falls with certain initiating characteristics (e.g., loss of consciousness, stroke, overwhelming external force from a motor vehicle accident, or violence) are often excluded from the definition of falls in older persons.56 The causes of these falls are different from the typical fall associated with neuromuscular and sensory impairment in an older person and are therefore a distinct topic. The committee concurs in this exclusion; consequently, such falls will not be covered in this chapter.
In 1986, there were 8,313 deaths from falls reported in the United States for persons aged 65 and older, making falls the leading cause of death from injury in the elderly.94 This number, derived from death certificates, may underestimate the number of deaths in which falls are a contributing factor.27,49 The rate of fall-related deaths rises rapidly with age for whites aged 70 and older; it rises less dramatically for nonwhites 75 and older (Figure 15-1). By age 85, approximately two-thirds of all reported injury-related deaths are due to falls.6 Older men are more likely than older women to die from a fall; the highest mortality rate occurs in white men aged 85 and over (171 per 100,000), followed by white women aged 85 and over (127 per 100,000). The rate of mortality from falls has declined in recent decades77 (Figure 15-2), which may reflect increased survival of hip fracture patients92 and improved trauma care.95 Some studies suggest