Is Kyphosis Related to Mobility, Balance, and Disability?

Objective: The aim of this study was to determine the association of increased kyphosis with declines in mobility, balance, and disability among community-living older adults. Design: The 18-mo follow-up visit data from 2006 to 2009 for 620 participants from the population-based Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly Boston Study of older adults was used. Cross-sectional multivariable regression analyses were performed to assess the relationship between kyphosis (measured using the kyphosis index) and measures of mobility performance (Short Physical Performance Battery), balance (Berg Balance Scale score), and disability (self-reported difficulty walking a quarter of a mile or climbing a flight of stairs). The authors then evaluated the men and the women separately. Adjustment variables included demographic factors (age, sex, race, and education), body mass index, self-rated health, comorbidities (heart disease, diabetes, stroke, and depressive symptoms), back pain, knee pain, and falls self-efficacy. Results: After full adjustment, greater kyphosis index was associated with lower Short Physical Performance Battery scores (adjusted beta = -0.08, P = 0.01) but not with lower Berg Balance Scale (adjusted beta = -0.09, P = 0.23) or self-reported disability (adjusted beta = 1.00; 95% confidence interval, 0.93-1.06) scores. In sex-specific analyses, kyphosis index was associated with only the Short Physical Performance Battery in the women. Conclusions: Greater kyphosis is associated with poorer mobility performance but not with poorer balance or self-reported disability. This association with the Short Physical Performance Battery was observed only among the women. Mechanisms by which increased kyphosis influences physical performance should be explored prospectively.