| Summary: | 碩士 === 華梵大學 === 工業工程與經營資訊學系碩士班 === 100 === Objective:The purpose of this study is to evalute the effects of the gender, handle position and handle angle on bi-manual lifting capacity.
Background: Manual materials handling (MMH) has been identified as one of the major causes of back injuries and musculoskeletal disorders to industrial workers and cost to industry. However, information regarding how the handle position and handle angle can affect two person lifting capacity is still insufficient.
Methodology: This study used the psychophysical approach to collected bi-manual lifting tasks capability for eight hour’s work shifts from knuckle height to floor height. A total of 28 subjects (14 males and 14 females) were reciuited in this study, the height difference of subjects was ±3 cm for each group, and the total members of group was 14 (7 group of males and 7 group of females ). A three-factor mixed design was employed, in which the independent variables included gender, handle position (upper, middle and lower) and handle angle (0°, 15° and 30°). The gender was between-subject design, and the handle position and angle was within- subject design. The criterium measures were bi-manual maximum acceptable weight of lifting (MAWL), increment of heart rate(△HR),and the subjective rating of perceived exertion(RPE).
Result: (1) Sex had a significant effect on MAWL and △HR, the MAWL of females decreased at a rate about 20% compared to the males, and the △HR of females significant larger than that of males. (2) MAWL and △HR values were significant influenced by handle position, and the MAWL of lower handle position was the largest,△HR of lower handle position was the smallest. (3) MAWL、△HR and wrist -RPE were significant influenced by handle angle, and the MAWL of 30° handle angle was the largest, △HR of 30° handle angle was the smallest, wrist –RPE of 30° handle angle is the best. (4) Sex and handle position had a significant interaction on △HR value. Sex and handle angle had a significant interaction on wrist-RPE value.
Conclusion: As the whole, except the male’s bi-manual lifting capacity significantly larger than that of the female’s, the present study also confirmed that a combination of lower handle position and with handle 30 ° angle is the best.
Application: This study suggests that the container handle should be designed ergonomically for manual material handling tasks industry to reduce the occupational injuries.
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