Executive functioning, concern about falling and quadriceps strength mediate the relationship between impaired gait adaptability and fall risk in older people

Background: Reduced ability to adapt gait, particularly under challenging conditions, may be an important reason why older adults have an increased risk of falling. This study aimed to identify cognitive, psychological and physical mediators of the relationship between impaired gait adaptability and fall risk in older adults. Methods: Fifty healthy older adults (mean +/- SD: 74 +/- 7 years) were categorised as high or low fall risk, based on past falls and their performance in the Physiological Profile Assessment. High and low-risk groups were then compared in the gait adaptability test, i.e. an assessment of the ability to adapt gait in response to obstacles and stepping targets under single and dual task conditions. Quadriceps strength, concern about falling and executive function were also measured. Results: The older adults who made errors on the gait adaptability test were 4.76 (95%CI = 1.08-20.91) times more likely to be at high risk of falling. Furthermore, each standard deviation reduction in gait speed while approaching the targets/obstacle increased the odds of being at high risk of falling approximately three fold: single task - OR = 3.10,95%CI = 1.43-6.73; dual task - 3.42,95%CI = 1.56-7.52. Executive functioning, concern about falling and quadriceps strength substantially mediated the relationship between the gait adaptability measures and fall risk status. Conclusion: Impaired gait adaptability is associated with high risk of falls in older adults. Reduced executive function, increased concern about falling and weaker quadriceps strength contribute significantly to this relationship. Training gait adaptability directly, as well as addressing the above mediators through cognitive, behavioural and physical training may maximise fall prevention efficacy.