BACKGROUND: Only a portion of the increased variability in gait parameters observed in ageing can be explained by age and gait speed alone. Other factors, like musculoskeletal changes of the spine, might contribute to higher variability of gait parameters, slower walking speed and subsequently increased fall-risk in ageing.
RESEARCH QUESTION: Are spinal posture and mobility related to 3D-accelerometry based gait analysis, functional performance and fall-risk in ageing?
METHODS: Forty elderly presenting increased fall-risk (OFR, 80.6 ± 5.4yrs), 41 old controls (OC, 79.1 ± 4.9yrs), and 40 young controls (YC, 21.6 ± 1.4yrs) were assessed for spinal posture and mobility (SpinalMouse®), gait analysis (DynaPort MiniMod), and functional performance (grip strength, grip work, timed-get-up-and-go-test, performance-oriented mobility assessment).
RESULTS: Compared to OC, OFR showed significantly (p < .05) larger trunk inclination angle (INC), smaller sacral extension mobility, slower walking speed, and lower medio-lateral step and stride regularity. Thoracic kyphosis angle (TKA) was similar in all groups. INC and sacral extension mobility showed the highest correlation with walking speed, gait parameters, functional performance and fall-risk. INC (OR = 1.14) and sacral extension mobility (OR = 1.12) can moderately explain fall-risk in elderly participants and showed fair capacity to discriminate OFR from OC, the diagnostic value on fall-risk is however low (best probabilistic cut-off value, INC: -0.83° [sensitivity = 70%, specificity = 61%, PPV = 64%, NPV = 68%, LR+ = 1.79, LR- = 0.49, AUC = 0.71]; sacral extension mobility: 8.5° [sensitivity = 70%, specificity = 73%, PPV = 72%, NPV = 71%, LR+ = 2.61, LR -= 0.41, AUC = 0.71]).
SIGNIFICANCE: Larger trunk inclination and smaller sacral extension mobility (i.e. hip extension mobility) are moderately related to increased fall-risk, gait alterations, lower muscle performance and worse functional mobility in ageing. Contrary to our hypothesis, TKA showed no relation with parameters of gait and/or fall-risk. INC and sacral extension mobility have fair discriminative power to distinguish older persons with increased fall-risk from those without and might be considered as therapeutic targets.