The results suggest that control of lateral stability may be an important area for fall-preventative intervention. The ability of a simple and safe force-plate measure of spontaneous postural sway to predict future falling risk suggests a possible clinical application as a preliminary screening tool for risk of falling.

A cross-sectional study was performed to investigate the association between fear of falling and postural performance in the elderly. One hundred ambulatory and independent volunteers (aged 62-96) were subjected to five types of balance tests: (a) spontaneous postural sway, (b) induced anterior-posterior sway, (c) induced medial-lateral sway, (d) one-leg stance, and (e) a clinical balance assessment scale. Pseudorandom platform motions were used in the induced-sway tests. The subjects were classified into both "faller"/"nonfaller" and "fear"/"no-fear" categories, to allow the influence of fear of falling and falling history to be separated in the analyses. Subjects who expressed a fear of falling were found to exhibit significantly poorer performance in blindfolded spontaneous-sway tests and in eyes-open, one-leg stance tests. The clinical scale was the only balance measure that showed a significant association with retrospective, self-reported falling history. We could not ascertain whether the fear of falling affected balance-test performance in an artifactual manner, or whether the fear and poorer performance were related to a true deterioration in postural control. Until this issue can be resolved, balance-test performance should be interpreted with caution when testing apprehensive individuals. Furthermore, studies of postural control and falling should allow for the potentially confounding influence of fear of falling.

Psychological indicators of balance confidence are important to measure both in conjunction with balance test performance and as a legitimate focus of rehabilitation. Of the various indicators assessed here, the dichotomous fear-of-falling question appears to have the least utility. Perceived need for personal assistance to ambulate outdoors has merit as an initial clinical screening question for discriminating persons on the basis of both physical ability and confidence. The ABC scale appears to have the greatest utility as an evaluative index for older persons at a moderate to high level of functioning.

A double-blind study was undertaken to determine the relationship (if one exits) between the extent of postural sway in standing of individual elderly subjects and their frequency of falling. A total of 205 subjects were studied; their average age was 81.8 years. Thirty per cent of the men, and 46% of the women, had one or more falls; the proportion of all subjects with one or more falls was 42%. The average speed of sway was significantly greater (P less than 0.05) for those who fell one or more times in a year than for those who did not fall. In this group of institutionalized elderly, there was no sex-related difference in the mean speed of sway; moreover, no age-related trend was demonstrated by the regression of mean speed upon age for all subjects. The mean speed of sway even for the non-fallers was found to be greater than that measured in a sample of non-institutional elderly subjects studied in the past. Thus, mean speed of postural sway was found to be only of statistical value for determining the risk of falling among these institutionalized elderly. We found postural sway to be an indicator of a tendency to fall, but the difference was less than might have been expected. No trend of increasing postural sway correlating with the increased frequency of falls was found.

Relative to questionnaires, performance measures were not found to be psychometrically superior, more acceptable to respondents, easier to administer, or easier to interpret. Neither type of measure by itself distinguishes between motivation and capability, reflects adaptations made in everyday living, or accounts for personal preferences or reasons for difficulty.