INTRODUCTION Poor lighting has been associated with stair falls in young and older adults. However, current guidelines for illuminating stairs seem arbitrary, differ widely between sources, and are often difficult to interpret. AIMS Here we examined the influence of real-world bulb illumination properties on stair descent safety in young and older adults, with a view to generating preliminary evidence for appropriate lightbulb use/stair illumination. METHODS Stair tread illumination (lx) was measured in a standard UK home (2.23 m ceiling) from a low (50 W; 630 lm) and a high (103 W, 1450 lm) power compact fluorescent lamp (CFL) bulb from the time they were turned on until they reached full brightness. This enabled modelling of their illumination characteristics during warm up. Illumination was also measured from a low (40 W, 470 lm) and a high (100 W, 1521 lm) power LED bulb at first turn-on. Computer-controlled custom lighting then replicated these profiles, in addition to a Bright control (350 lx), on an instrumented staircase descended (3 × trials per light condition) by 12 young (25.3 ± 4.4 years; 5 males), 12 higher ability older (HAOA: 69.6 ± 4.7 years; 5 males) and 13 lower ability older (LAOA: 72.4 ± 4.2; 3 males) healthy adults. Older adults were allocated to ability groups based on physiological and cognitive function. Stair-specific confidence was assessed prior to the first descent in each new lighting condition, and whole-body 3D kinematics (Vicon) quantified margins of stability and foot clearances with respect to the step edges. Mixed ANOVAs examined these measures for within-subject effects of lighting (×5), between-subject effects of age (×3) and interactions between lighting and age. RESULTS Use of CFL bulbs led to lower self-reported confidence in older adults (20.37%, p = .01), and increased margins of stability (12.47%, p = .015) and foot clearances with respect to the step edges (10.36%, p = .003). Importantly, using CFL bulbs increased foot clearance variability with respect to the bottom step (32.74%, p = .046), which is where a high proportion of falls occur. CONCLUSION Stair-tread illumination from CFL bulbs at first turn on leads to less safe stair negotiation. We suggest high powered LED bulbs may offer a safer alternative.

中文翻译：

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楼梯安全的最佳照明水平：灯泡类型和亮度对置信度，动态平衡和步进特性的影响。

简介照明不良与年轻人和老年人的楼梯跌落有关。但是，当前照亮楼梯的指南似乎是任意的，各光源之间差异很大，并且通常难以解释。目的在这里，我们检查了现实世界中灯泡照明特性对年轻人和老年人楼梯下降安全性的影响，以期为适当的灯泡使用/楼梯照明产生初步证据。方法从那时起，在标准的英国家庭（天花板为2.23 m）中，从低功率（50 W； 630 lm）和高功率（103 W，1450 lm）的紧凑型荧光灯（CFL）灯泡中测量了楼梯的踏板照度（lx）将它们打开直到达到全亮度。这样就可以在预热期间对其照明特性进行建模。还从低（40 W，首次开启时为470 lm）和高功率（100 W，1521 lm）的LED灯泡。然后，由计算机控制的自定义照明在Brightlight控件（350 lx）的基础上复制了这些配置文件，在由12个年轻人（25​​.3±4.4岁； 5个男性），12个更高能力的下降的仪器楼梯上（每个光照条件进行3次试验）年龄较大的人（HAOA：69.6±4.7岁； 5名男性）和13位年龄稍低的健康成年人（LAOA：72.4±4.2； 3名男性）。根据生理和认知功能，将老年人分为能力组。在每种新的照明条件下，在首次下降之前评估特定于楼梯的置信度，并且全身3D运动学（Vicon）量化了相对于台阶边缘的稳定性和脚间隙的裕度。混合方差分析检查了这些措施对于照明的内部影响（×5），年龄（×3）的主体间效应以及光照和年龄之间的相互作用。结果使用CFL灯泡导致老年人自我报告的信心降低（20.37％，p = .01），并增加了稳定裕度（12.47％，p = .015）和相对于踏板边缘的脚间隙（10.36） ％，p = .003）。重要的是，使用CFL灯泡相对于底部台阶而言，增加了脚部间隙的变化性（32.74％，p = .046），在该位置上，摔倒发生的比例很高。结论首次打开CFL灯泡的阶梯式照明会导致楼梯协商的安全性降低。我们建议大功率LED灯泡可以提供更安全的选择。015）和相对于踏板边缘的底脚间隙（10.36％，p = .003）。重要的是，使用CFL灯泡相对于底部台阶而言，增加了脚部间隙的变化性（32.74％，p = .046），在该位置上，摔倒发生的比例很高。结论首次打开CFL灯泡的阶梯式照明会导致楼梯协商的安全性降低。我们建议大功率LED灯泡可以提供更安全的选择。015）和相对于踏板边缘的底脚间隙（10.36％，p = .003）。重要的是，使用CFL灯泡相对于底部台阶而言，增加了脚部间隙的变化性（32.74％，p = .046），在该位置上，摔倒发生的比例很高。结论首次打开CFL灯泡的阶梯式照明会导致楼梯协商的安全性降低。我们建议大功率LED灯泡可以提供更安全的选择。