Falls in the elderly related to postural imbalance.

Abstract

prolonged serum levels exceeding 8-10 ,ug/ml. In cases 1 and 2 the immediate and dramatic changes occurred with levels greater than this. In case 3 lesser changes occurred even though the serum levels were in the "safe" range. The basal turn of the cochlea seems most vulnerable to both immediate and delayed effects, both of which may produce the dissociated pattern of AP response that is well recognised in high-tone sensory deafness of whatever cause.10The speed of onset of the observed effect suggests a direct action at a site in the cochlea, involving a temporary metabolic block-for example, interference with an energy requiring process or blocking of transport of cations across cell membranes. There is experimental and clinical evidence to show that aminoglycosides interfere with calcium metabolism (probably by binding).21-14 In the lateral line organ of the fish they may block potassium transport.15 Both these effects are rapid and may be reversed by administering the appropriate cation in solution. Other metabolic effects follow intoxication with aminoglycosides, although their speed of onset is not clearly established. Guinea-pigs treated with tobramycin sustain most outer hair cell damage in areas of the cochlea where there is the least amount and smallest granule size of glycogen-namely, the basal turn. The greatest oxygen consumption of the cochlea occurs in the basal turn, and is decreased by kanamycin.17 The adenosine triphosphatase hydrolysing system has been shown to be modified within the microstructures of the cochlea after the administration of aminoglycosides.'8 This may have an important effect on the function of the stria vascularis, which uses adenosine triphosphatase to support a sodium-potassium ion pump to maintain endolymphatic homoeostasis. The possibility that interference with protein synthesis caused of our observed changes is ruled out by their speed of onset.How our findings relate to long-term ototoxicity is not clear. Summary Two hundred and forty-three elderly people aged 60 to 96 years were questioned about their falls, and their sway was measured. For comparison sway was also measured in 63 younger subjects. Sway increased with age and was higher in women at all ages. There was no difference in sway between those with no history of falls and those who fell only because of tripping. In both sexes sway was significantly increased in people who fell because of loss of balance and in women whose falls were due to giddiness,

Obstacle negotiation kinematics: age-dependent effects of postural threat

“…It is also evident that tripping is one of the major causes of reported falls, accounting for half of the reported falls in the elderly each year (Overstall et al, 1977). Many factors play a role in determining whether or not an individual is at a risk for falling.…”

“…Indeed, external factors such as icy sidewalks, poorly lit hallways, narrow walkways, and obstacles frequently contribute to the challenge OA have in maintaining their balance. Tripping over obstacles is one of the most common causes of reported falls in the elderly (Overstall et al, 1977). In fact, uneven pavement was the leading cause of falls in one year (Crosbie & Ko, 2000).…”

Mirror versus stationary cross feedback in controlling the center of foot pressure displacement in quiet standing in elderly subjects

“…In addition to high medical expenses that falls pose to the public health service, the consequences for elderly persons are dramatic because of their association with physical and psychological trauma, reduced activity, loss of independence, decreased quality of life and even injury-related deaths. Although falling is a complex and multifactorial problem (5-7), decreased postural control is usually considered as a major contributing factor (8)(9)(10)(11)(12)(13)(14). More precisely, posturographic parameters of mediolateral (ML) postural sway measured in unperturbed stance were shown to be the most strongly associated with a history of falls and to be the best predictors for risk of falling in an elderly population (11,12).…”

Aging effects on joint proprioception: the role of physical activity in proprioception preservation

“…Moreover, Camicioli et al [13] showed that the disruption of proprioceptive input was the most important determinant of quantitative balance performance in subjects older than 80 years. Decline in lower limb proprioception has been linked to balance problems found in the elderly [26,34,36,80], which have, in turn, been associated with the higher incidence of falls [35,48,64,72]. Falls not only lead to subsequent personal and social consequences of injury and loss, but are also a major cause of death in older people.…”