The Relationship Between Hip Displacement In The Anteroposterior Direction And Life-space Mobility Among Older Women

Abstract

PURPOSE: The ability to recover one’s balance using a hip-based strategy is important to avoid falls, but many older adults have limited hip flexibility. This study aimed to clarify the relationship between hip displacement during voluntary motion (Hip-D) in the anteroposterior direction and life-space mobility, and to examine whether Hip-D could be used to independently distinguish the quality of one’s life-space mobility by comparing the results on the Life-Space Assessment (LSA) scale. METHODS: Hip-D and physical functions related to fall prevention were measured in 319 community-dwelling older women. Hip-D was defined as the maximum moving distance of the great trochanter in the anteroposterior direction. The participants were also classified into good and poor life-space mobility groups based on their LSA scores. The ability of the Hip-D and physical functioning tests to distinguish the above groups was determined using DeLong’s test of the area under the receiver operating characteristic curve (AUC) for each test. RESULTS: Hip-D was significantly greater in the good life-space group (25.2 ± 6.9 cm) than in the poor life-space group (17.3 ± 5.1cm). The LSA score was moderately correlated with Hip-D (r = 0.51, p < 0.05) but only weakly with the fall-related physical functioning parameters (|r| = 0.15-0.39). Hip-D had the highest AUC (0.824, 95%CI: 0.776-0.872) among all parameters, and the Hip-D cutoff value was 20.9 cm. The AUC for Hip-D was significantly greater than those for all fall-related physical functioning parameters (AUC = 0.591-0.754) in an examination based on DeLong’s test. CONCLUSIONS: Hip-D measurements of older adults were easy to obtain and were moderately correlated with life-space mobility. As such, this approach represents a useful way to predict life-space mobility. Hip-D measurements proved to be more reliable for this purpose than the other fall-related physical functioning parameters studied. It will be necessary the care prevention exercise to improve Hip-D (at least over 21 cm) for older adults.