Relationship Between Kyphotic Posture and Falls in Community-Dwelling Men and Women

Abstract

STUDY DESIGN: A cohort study using data from the Locomotive Syndrome and Health Outcome in Aizu Cohort Study, a population-based prospective cohort study of residents of the towns of Tadami and Minamiaizu in Fukushima Prefecture, Japan. OBJECTIVE: The aim of this study was to clarify the association between kyphotic posture and falls, and to investigate the presence or absence of sex differences. SUMMARY OF BACKGROUND DATA: In our literature review, we found no studies focusing on sex differences in the association between kyphotic posture and falls. METHODS: We included subjects aged more than 40 years who participated in annual health check-ups from 2009 to 2010. We analyzed the effects of kyphotic posture, measured using the wall-occiput test (WOT), on falls, adjusting for potential confounders, such as age, body mass index, symptoms of depression, sedative medication, and other comorbidities. RESULTS: We enrolled a total of 1418 subjects into primary analyses (593 men, 825 women; mean [standard deviation] age, 68.1 [7.7] yrs). We then stratified subjects into the following groups according to the degree of kyphotic posture: nonkyphotic posture (n = 1138, 80.3%), mild kyphotic posture (n = 172, 12.1%), and severe kyphotic posture (n = 108, 7.6%). We observed no significant difference in the severity of kyphotic posture between men and women (P = 0.18). Overall, 284 subjects (20.0%) experienced at least one fall during the one-year period. After adjustment for potential confounders using a logistic regression model, we observed a significant association between severe kyphotic posture and falls for men [odds ratio (OR) 2.14 (1.01-4.57); P = 0.048]. In contrast, we observed no significant association for women [OR for severe kyphotic posture 0.80 (0.43-1.50), OR for mild kyphotic posture 0.91 (0.53-1.57)]. CONCLUSION: We identified a sex difference in the association between kyphotic posture and falls in community-dwelling adults. In particular, severe kyphotic posture might only increase the incidence of falls in men. LEVEL OF EVIDENCE: 3.