• Safety on stairs: Influence of a tread edge highlighter and its position

      Foster, Richard J.; Hotchkiss, John; Buckley, John G.; Elliott, David B. (2014-07)
      Background: Falls sustained when descending stairs are the leading cause of accidental death in older adults. Highly visible edge highlighters/friction strips (often set back from the tread edge) are sometimes used to improve stair safety, but there is no evidence for the usefulness of either. Objective: To determine whether an edge highlighter and its location relative to the tread edge affect foot placement/clearance and accidental foot contacts when descending stairs. Method: Sixteen older adults (mean ± 1 SD age; 71 ± 7 years) with normal vision (experiment 1) and eight young adults (mean ± 1 SD age; 24 ± 4 years) with visual impairment due to simulated age-related cataract (experiment 2) completed step descent trials during which a high contrast edge highlighter was either not present, placed flush with the tread edge, or set back from the edge by 10 mm or 30 mm. Foot placement/ clearance and the number of accidental foot contacts were compared across conditions. Results: In experiment 1, a highlighter set back by 30 mm led to a reduction in final foot placement (p b 0.001) and foot clearance (p b 0.001) compared to a highlighter placed flush with the tread edge, and the percentage of foot clearances that were less than 5 mm increased from 2% (abutting) to 17% (away30). In experiment 2, a highlighter placed flushwith the tread edge led to a decrease in within-subject variability in final foot placement (p = 0.004) and horizontal foot clearance (p = 0.022), a decrease in descent duration (p = 0.009), and a decrease in the number of low clearances (b5 mm, from 8% to 0%) and the number of accidental foot contacts (15% to 3%) when compared to a tread edge with no highlighter present. Conclusions: Changes to foot clearance parameters as a result of highlighter presence and position suggest that stairswith high-contrast edge highlighters positioned flushwith the tread edgewill improve safety on stairs, particularly for those with age-related visual impairment.