Assessment of the best gait parameter in relation to bone status in community-dwelling young-old and old-old women in Japan.

Even if physical exercise contributes to bone health of the elderly, intense activities have the potential to worsen the risk of osteoporosis. This fact and the inevitable decrease of mobility with age increase the likelihood that the mobility parameter that best benefits bone health differs with age. The aim of this study was to objectively assess the gait parameter that most strongly influences bone health of young-old and old-old women. Subjects comprised 200 community-dwelling elderly women (132 young-old, 68 old-old) registered at welfare centers for the aged. Bone status was examined in the right heel by quantitative ultrasound (QUS) and indicated as stiffness index (SI). Gait parameters including usual and maximum walking speed (UWS and MWS, respectively), daily walking steps (DWS), obstacle-negotiating gait, and stair-climbing were examined objectively. Other bone-related physical factors (body components, handgrip strength, and masticatory function) were measured and adjusted while performing assessment. After adjustment for covariates, multiple linear regression analysis showed that MWS had the strongest association with SI in young-old women and DWS had the strongest association with SI in old-old women. To prevent osteoporosis, brisk walking exercise and engaging in movement in everyday life, respectively, should be advocated for young-old women and old-old women in Japan.