Weak hip flexor strength predicts progression of functional capacity decline due to locomotor system dysfunction in community-dwelling older adults: A longitudinal cohort study

Abstract

Purpose: It is critical to determine the risk factors for activities of daily living (ADL) disability caused by locomotor dysfunction. However, no longitudinal study has investigated the association between disability due to locomotive dysfunction and multidimensional factors. Therefore, we investigated the relationship between the progression of functional capacity decline due to locomotive dysfunction and multiple physical functions among older adults in a longitudinal study. Methods: The participants comprised of 433 community-dwelling older adults. Physical function was assessed at baseline, which included handgrip strength, maximal isometric strength of hip flexion, hip extension, hip abduction, knee extension, toe flexion (index for muscle strength), the 5-time chair-stand test (index for muscle power), the one-legged stance and timed ‘‘Up & Go’’ tests (index for balance function), the 30-s stair test (index for muscle endurance), and range of motion (ROM) (an index of joint condition). Functional capacity decline due to locomotive dysfunction was assessed using the 25-question Geriatric Locomotive Function Scale (GLFS-25) before and after a 12-month period. Based on changes in the GLFS-25 score compared with baseline, the non-decline and decline groups were operationally defined. Logistic regression analyses with the groups as the dependent variable and physical function as independent variables were performed. Results: Of the 433 participants, 189 (43.6%) were included in the decline group. Logistic regression analysis revealed hip flexor strength as a primary determinant in the progression of functional capacity decline. Conclusion: These results suggest that among physical functions, hip flexor strength influences the progression of disability resulting from locomotive dysfunction in older adults.