The effects of loading moving angles, heights and frequencies on asymmetrical lifting and lowering abilities

• Main Authors: Lin, You-Sen, 林友森
• Other Authors: Ho, Cheng-Pin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/22128433492215240933

碩士 === 國立屏東科技大學 === 工業管理系 === 93 === The aim of the study is to investigate loading moving angles, heights and frequencies on asymmetrical lifting and lowering abilities. Lift work mainly uses the muscular force of the lower back. When the height increase, the main muscular group is upper limbs, and the difference in the muscular forces of the left and right hands may influence the results. The lift and lower abilities differ according to the difference of the muscular group. This study recruited 8 right-handed students, and simulated 8 hours work with psychophysics. Each subjects was tested for 24 works (3 loading moving angles: 0°, -90°, 90°; 2 heights: K-S, S-R; 2 frequencies: 1 lift/min, 4 lifts/min; 2 handling mode: lift, lower), and psychophysics was used to collected indices, including MAWL, MAWLo, HR and RPE. The results showed that the MAWL has significant difference in the loading moving angles of 0° and -90°, but not in 90° and other two angles. Also, MAWL decreases as the height and frequency increase. The findings showed that when the non-preferred hand was used for high and quick work, and the loading position is on the left, the lift ability is inferior. On the other hand, MAWLo decreases as the height and frequency increase, but has no difference in terms of the angle. Comparing MAWL and MAWLo, under different heights and frequencies, MAWL is smaller than MAWLo in all cases, showing that when the height is over knuckle height, MAWL is recommended for load limit. HR increases as the height and frequency increase, RPE increases as the frequency increases; both show no difference under different angles. As for different body parts, the upper limbs, such as left and right wrists are more easily tired.