Gait Variability Detects Women in Early Postmenopause With Low Bone Mineral Density

Background Women in early postmenopause and with low bone mineral density (BMD) may exhibit early markers for physical frailty as a result of sarcopenia and osteopenia. Objective The purpose of this study was to determine whether women in early postmenopause and with low BMD exhibit decreased physical performance and differences in gait variability and fall and fracture rates. Design This study was an observational cohort design with participants assigned to groups on the basis of BMD status. Methods Fifty-four women, 31 with low BMD and 23 with normal BMD, participated. This study was conducted in a university research facility. Physical performance was measured by assessment of dynamic balance (timed backward tandem walk test), strength (handheld dynamometry of isometric quadriceps muscle force production), and free gait speed. Gait variability was assessed on the basis of the coefficient of variation for temporal-spatial gait characteristics. Falls and fractures were assessed for the year after initial testing. Results Significant between-group differences were found for step time and stance time variability. Limitations The limitations of this study included group assignment on the basis of the results of the most recent bone density scan within the preceding 2 years. Conclusions Women in early postmenopause and with low BMD exhibited increased gait variability in step time and stance time but did not exhibit differences in balance, strength, or gait speed. Gait variability may be more sensitive for detecting differences in women in early postmenopause and with or without low BMD than more typical measures of physical performance.