Associations of Lower-Limb Phase Angle with Locomotion and Motor Function in Japanese Community-Dwelling Older Adults

Whole-body phase angle (PhA) is associated with motor function and geriatric diseases. However, it was unclear which parts of the upper- or lower-limb PhA were involved. This study investigated the differences in the PhA of the upper and lower extremities and their relationships with frailty, locomotive syndrome indices, and motor function in community-dwelling older adult participants. This study was a cross-sectional observational study. In 69 community-dwelling older adults, the PhA at each measurement site (whole body, upper limbs, and lower limbs), motor function, Kihon Checklist (KCL), and 25-Geriatric Locomotive Function Scale (GLFS-25) were measured. This study examined differences in each PhA and its relationship with motor function and geriatric diseases. Multiple regression analysis was performed using GLFS-25 as the dependent variable and sex and lower-limb PhA as independent variables. In this cohort (mean age: 72.3 ± 5.7 years; 18 males and 51 females), lower-limb PhA was significantly lower than upper-limb PhA. Unlike other PhAs, lower-limb PhA was related to grip strength, TUG, F/w, and GLFS-25. Multiple regression analysis showed that the lower-limb PhA was independently related to GLFS-25. Cellular health of the lower extremity is associated with gait, standing function, and indicators of locomotive syndrome.