Locomotive dysfunction and spinopelvic sagittal alignment in relation to falls and stumbling in community-dwelling adults: a cross-sectional study

Abstract Falls and stumbling are commonly analyzed as a single outcome, although only falls cause injury and the two events may have different correlates. We examined both in 531 adults from the 2021 Iwaki Health Promotion Project who answered separate questions about falls and stumbling and underwent standing full-spine lateral radiography. Logistic regression models included age, sex, skeletal muscle index, sleep medication use, the 25-question Geriatric Locomotive Function Scale (GLFS-25), and one spinopelvic sagittal parameter. Overall, 83 participants (15.6%) reported a fall, 165 (31.1%) stumbling, and 188 (35.4%) either event. GLFS-25 was associated with all outcomes in every age stratum: the adjusted odds ratio per point was 1.095 (95% CI 1.055–1.137) for either event and 1.062 (1.028–1.098) for falls alone. Removing its two anxiety items reduced the area under the curve only from 0.702 to 0.682. Sagittal alignment was significantly associated only with stumbling: a smaller sagittal vertical axis in participants aged < 65 years and a larger T1 pelvic angle in those aged ≥ 65 years. However, multinomial regression did not distinguish its associations with stumbling and falls. Locomotive dysfunction was associated with both events and can be assessed without equipment, whereas the radiographic findings should be considered hypothesis-generating.