The Effect and Verification of Psychophysical Instructions on the Capability of Manual Materials Handling

• Main Authors: Peng-Shun Ling, 凌鵬舜
• Other Authors: Swei-Pi Wu、Cheng-Pin Ho
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/48881586960119465442

碩士 === 華梵大學 === 工業管理學系碩士班 === 91 === Snook and Irvine (1967) first adopted the concept of psychophysics in the research of manual materials handling for approximately three decades. Numerous researchers have utilized psychophysics to measure the maximum acceptable weight of lift (MAWL) under different working conditions and MAWL has become one of the major factors to develop guidelines. This technique allows the subjects to adjust the weight lifted (stimulus magnitude) according to their sensation (sensation magnitude) under different conditions using the help from “psychophysical instruction”. Obviously, the development of psychophysical instruction is very important because it is hard to quantify the amount of stimulus magnitude to sensation magnitude. The instruction developed by Snook et al. 1970 is the standard version of using psychophysical approach in MMH. However, the instructions may lead the MAWL is too big to damage the back for the assumptions of piecework rate and it didn’t highlight the importance of safe lift. Karwowski et al. (1999) developed a new edition of instruction which it didn’t mention the piecework rate and emphasize safe lift. They named the weight lift under the new instruction as “maximum safe weight of lift” (MSWL). Their research shows that the MSWL is significantly lower than MAWL. This research divided 16 participants into 2 groups according to their abilities of one time maximum lift. Different instructions assigned to them to develop MAWL and MSWL separately. The result shows that MAWL is significantly higher than MSWL which means the psychophysical instruction should be changed to Karwowski’s edition when psychophysical approach is applied to manual handling task design.