Stairs are associated with falls, especially when step dimensions are inconsistent. However, the mechanisms by which inconsistencies cause this higher risk are mostly theoretical. In this experimental study we quantified the effect of inconsistent rise heights on biomechanical measurements of stepping safety from younger (n = 26) and older adults (n = 33). In ascent, both groups decreased foot clearance (~9 mm) over the inconsistently higher step (F(1,56) = 48.4, p < 0.001). In descent, they reduced foot contact length on the higher step by 3% (F(1,56) = 9.1, p < 0.01). Reduced clearance may result in a toe-catch potentially leading to a trip, while reduced foot contact lengths increase the risk of overstepping which may also lead to a fall. These effects occurred because participants did not alter their foot trajectories, indicating they either did not detect or were not able to adjust to the inconsistent rise, increasing the likelihood of a fall. Consistent stair construction is vital, and existing inconsistencies should be identified and safety interventions developed.

楼梯与跌倒有关，尤其是在台阶尺寸不一致时。但是，不一致导致这种较高风险的机制大部分是理论上的。在这项实验研究中，我们量化了不一致的上升高度对年轻人（n = 26）和老年人（n = 33）的踩踏安全性的生物力学测量的影响。在上升过程中，两组的脚步间隙在不一致的较高步长下均减小（〜9 mm）（F（1,56）= 48.4，p <0.001）。在下降时，他们将较高步的脚部接触长度减少了3％（F（1,56）= 9.1，p <0.01）。减小的间隙可能会导致脚趾卡住，从而可能导致绊倒，而减小的脚接触长度会增加踩踏的风险，这也可能导致跌倒。发生这些效果是因为参与者没有改变他们的脚部轨迹，表示他们没有检测到或无法适应不一致的上升，从而增加了跌倒的可能性。始终如一的楼梯构造至关重要，应识别现有的不一致之处并制定安全干预措施。