Author(s): HIWA, T., INOUE, S., KUNIMASA, Y., KATO, R., AMANO, T., HASEGAWA, K., Institution: NIIGATA UNIVERSITY, Country: JAPAN, Abstract-ID: 1874

INTRODUCTION:
In Japan, prevention of falls among older individuals is an urgent social and public health problem, while proper methods for assessing fall risk have yet to be established. Conventional fall risk assessments primarily rely on static or single-task measures such as grip strength, the Timed Up and Go test, and the Functional Reach test. However, these measures are likely insufficient to evaluate dynamic physical abilities required to prevent falls, such as footstep reactions and movements to sudden fall induction. In this study, we developed a novel fall-induction device that induces stepping reactions to avoid falls following postural perturbation. The purpose of this study was to evaluate the usefulness of the fall-induction device for assessing fall risk in young adults, classified according to fall history and exercise habits.
METHODS:
A total of 117 healthy young adults (48 men, 69 women) were classified by fall history (with or without previous fall experiences, n = 21/96) and exercise habits (active or inactive, n = 49/68). Measurements included body composition, grip strength, and balance-related variables (e.g., the Functional Reach test) as conventional fall-risk assessments. In addition, new indices were obtained using the developed fall-induction device. Participants stood upright on the device board and shifted their body weight forward, which caused the board to tilt anteriorly and induced a stepping response to prevent falling. This device measured foot reaction time, time to establish a stable base of support, stepping distance, and footstep speed, thereby evaluating dynamic physical ability related to fall-prevention-like movements. Intergroup comparisons were conducted using an unpaired t-test or a two-way analysis of variance (ANOVA) with fall history and exercise habits as independent factors.
RESULTS:
Participants with a fall history showed shorter stepping distances and slower foot speed than those without a fall history (both p = .005). Within-sex analysis showed that the trend in stepping distance was apparent in males (p = .016) but not in females (p = .157). In addition, males with a fall history and exercise habits tended to alter foot speed with slower and faster responses, respectively (p = .053 and p = .079, respectively). Females with exercise habits showed faster movement time and footstep speed than those without exercise habits (p = .012 and p = .002, respectively). Furthermore, females with a fall history showed attenuated grip strength compared with those without a fall history (p = .002).
CONCLUSION:
Fall history showed negative, while exercise habits showed positive outcomes in stepping distance and foot speed, and biological sex likely modulates these effects. Notably, the group- and sex-dependent findings obtained from the fall-induction device were not clearly detected by conventional assessment measures, suggesting the potential of our device as a practical screening tool for early fall risk assessment in young healthy adults.