Simeonov P, Hsiao H, Powers J, Ammons D, Kau T, Cantis D, Zwiener J, Weaver D
Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA.
Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA.
Appl Ergon. 2017 Mar;59(Pt A):460-469. doi: 10.1016/j.apergo.2016.10.008. Epub 2016 Oct 22.
This study evaluated the effect of an extension ladder "walk-through" top design on kinetic and kinematic behaviors and the outward destabilizing forces induced on the ladder during transitioning at elevation. Thirty-two male participants performed stepping tasks between a ladder top and a roof at simulated elevation in a surround-screen virtual-reality system. The experimental conditions included a "walk-through" and a standard ladder top section supported on flat and sloped roof surfaces. Three force platforms were placed under the ladder section and in the roof to measure propulsion forces during transitions. A motion measurement system was used to record trunk kinematics. The frictional demand at the virtual ladder base was also calculated. The results indicate that under optimal ladder setup (angle 75.5 °), the frictional demand at the ladder base remains relatively small for all experimental conditions. Also, the "walk through" ladder top eased the ladder-to-roof transitions but not the roof-to-ladder transitions.
本研究评估了一种伸缩梯“穿行式”顶部设计对动力学和运动学行为的影响，以及在高处过渡期间在梯子上产生的向外不稳定力。32名男性参与者在环绕屏幕虚拟现实系统中，于模拟高处的梯子顶部和屋顶之间执行踏步任务。实验条件包括在平坦和倾斜屋顶表面上支撑的“穿行式”和标准梯子顶部部分。在梯子部分下方和屋顶放置了三个力平台，以测量过渡期间的推进力。使用运动测量系统记录躯干运动学。还计算了虚拟梯子底部的摩擦需求。结果表明，在最佳梯子设置（角度75.5°）下，所有实验条件下梯子底部的摩擦需求相对较小。此外，“穿行式”梯子顶部使梯子到屋顶的过渡更容易，但屋顶到梯子的过渡并非如此。
