A novel biomechanical profiling approach surpasses the outcome of current tools for the prediction of stair falls

By Dr Thijs Ackermans

Stair negotiation is one of the most hazardous daily tasks for older adults, often resulting in falls. Indeed, falls on stairs have been identified as the leading cause of accidental death and place a substantial financial burden on the National Health Service in the UK. Identifying the individuals at risk for a fall is necessary to deliver effective fall prevention interventions. However, presently there are no specific screening tools for stair fall prediction. It is questionable whether generic fall screening methods can identify older people at risk for falls on stairs, especially as stair negotiation is a complex and specific skill. In this study, we aimed to investigate whether stair fallers could be differentiated from non-stair-fallers by biomechanical risk factors or physical and psychological parameters included in existing fall screening methods. In addition, we aimed to identify the individuals with the highest stair fall risk using a novel multivariate stepping profiling method.

Eighty-seven older adults negotiated an instrumented seven-step staircase (Figure) and performed assessments of physical and psychological function. We monitored falls and events of balance perturbation (combined as “hazardous events”) in daily life during a 12-month follow-up. We found that the physical and psychological parameters did not predict hazardous events on stairs. We further found that the Fall Risk Assessment Tool (FRAT), which is commonly used in the UK, classified only 1 out of the 17 stair fallers identified during the follow-up as being at risk for a fall. We found that single biomechanical risk factors could not predict hazardous events on stairs either. We then used K-means clustering to profile the overall stair negotiation behaviour of the older adults using biomechanical parameters indicative of fall risk as input (such as, foot clearance and the required coefficient of friction). This stepping profiling method identified that were linked with hazardous for stair ascent.

Our findings highlight the potential of our stepping profiling method to predict stair fall risk in older adults against the limited predictability of the FRAT and single parameter approaches currently used as screening tools. Future research should this novel method in larger populations in real life stair negotiation conditions to improve the predictive power and validate the stepping profiling method. This could eventually result in the development of targeted interventions for improving stair safety in older individuals.

Figure. Custom-built instrumented seven-step staircase used in the present study.

Publication

Ackermans, T., Francksen, N., Lees, C., Papatzika, F., Arampatzis, A., Baltzopoulos, V., Lisboa, P., Hollands M., O’Brien T., Maganaris, C. (2020). Prediction of balance perturbations and falls on stairs in older people using a biomechanical profiling approach: A 12-month longitudinal study. The Journals of Gerontology: Series A. https://doi.org/10.1093/gerona/glaa130

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