Davis Kermit G, Orta Anés Lida
Low Back Biomechanics and Workplace Stress Laboratory, Department of Environmental Health, University of Cincinnati, Cincinnati, OH, USA.
Appl Ergon. 2014 Mar;45(2):285-92. doi: 10.1016/j.apergo.2013.04.010. Epub 2013 May 9.
While the workers of the Wholesale and Retail Trade industrial sector suffer from musculoskeletal disorders at an alarming rate, there have been few investigative studies into potential effective interventions to reduce the ergonomic stress. The objective of the study was to determine whether a cart with an adjustable shelf could reduce awkward postures and motions while stocking products in a grocery store. Fifteen workers at a small grocery store in Puerto Rico completed stocking tasks with two types of carts: traditional and adjustable height cart or Ergo Cart. Trunk kinematics, LBD risk index, NIOSH lifting index, subjective ratings, and productivity indicators were collected during four typical stocking tasks. The Adjustable Ergo Cart reduced the sagittal trunk flexion by 7° and velocity by about 5°/s but increased twisting by about 2° and twist velocity by 4°/s as compared to the traditional cart. The LBD risk index was reduced by a small 2.4% in probability although greater reductions were found for larger items (e.g. bags of dog food and 2-L of Soda). The consensus among workers was that the adjustable cart would be easier to use. Overall, the study provides objective evidence that an ergonomically designed cart (e.g. adjustable height) has some potential to reduce sagittal trunk flexion, LBD risk index, and the NIOSH lift index. Overall, the results indicate that any intervention such as an adjustable cart can only have marginal effectiveness unless the entire systems perspective is considered.
虽然批发和零售贸易行业的工人遭受肌肉骨骼疾病的比例高得惊人，但针对减少人体工程学压力的潜在有效干预措施的调查研究却很少。本研究的目的是确定带有可调节搁板的推车在杂货店备货时是否能减少别扭的姿势和动作。波多黎各一家小杂货店的15名工人用两种类型的推车完成了备货任务：传统推车和高度可调节推车（即人体工程学推车）。在四项典型的备货任务中收集了躯干运动学、腰背痛风险指数、美国国家职业安全与健康研究所（NIOSH）提举指数、主观评分和生产率指标。与传统推车相比，可调节人体工程学推车使矢状面躯干前屈减少了7°，速度降低了约5°/秒，但扭转增加了约2°，扭转速度增加了4°/秒。腰背痛风险指数的概率小幅降低了2.4%，不过对于较大的物品（如狗粮袋和2升装汽水），降低幅度更大。工人们的共识是可调节推车使用起来会更方便。总体而言，该研究提供了客观证据，表明符合人体工程学设计的推车（如高度可调节）有一定潜力减少矢状面躯干前屈、腰背痛风险指数和NIOSH提举指数。总体而言，结果表明，除非从整个系统的角度考虑，否则任何干预措施（如可调节推车）都只能产生有限的效果。
