Effects of changes in sitting work posture on static neck and shoulder muscle activity: Schuldt, K., Ekholm, J., Harms-Ringdahl, K., Nemeth, G., and Arborelius, U.P.Ergonomics, 1986, 29.12, 1525–1537

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 153 KB
• Volume: 19
• Category: Article
• ISSN: 0003-6870
• DOI: 10.1016/0003-6870(88)90220-7

✦ Synopsis

A laboratory study was conducted to evaluate the NIOSH guidelines for manual lifting. Thirteen male subjects were required to lift three different boxes (25, 38 and 51 cm wide), at four different frequencies (0"2, 3, 6 and 9 lifts/min), and at two heights (floor level to bench height (0"8 m) and bench height to 1'5 m). Each lift was performed for one hour. Maximum permissible limits (MPL) were computed for all the subjects and the lifting tasks. A psychophysical method was used to determine the maximum acceptable weight of lift. However, this weight was not allowed to exceed the corresponding MPL. Maximum acceptable weights for all 13 subjects were equal to the MPLs. Nine out of 13 subjects indicated that they could lift significantly greater than the MPLs. MPL for the bench to 1"5 m height was significantly greater than the corresponding MPL for the floor to 0"8 m height. The mean heart rate at MPL for one-hour lifting tasks ranged from 104 to 114 beats/min. An important finding was that there were large differences in MPL between subjects for a given lifting task due to differences in horizontal distance. It is concluded that the maximum permissible limits for one-hour lifting tasks are conservative as compared to psychophysical and physiological data especially for lifting near the floor level. Future needs to improve the accuracy and applicability of the guidelines are discussed.

19.1.12 (104393) Nagashima, K., and Konz, S.