| Author: | Li, Lam |
| Title: | Relationship between the self-perceived physical exertion and the actual exertion on lifting performance : a comparison of experienced workers and healthcare professionals |
| Degree: | M.Sc. |
| Year: | 2002 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Lifting and carrying -- Physiological aspects Lifting and carrying -- Evaluation |
| Department: | Multi-disciplinary Studies Department of Rehabilitation Sciences |
| Pages: | xiv, 112 leaves : ill. (some col.) ; 30 cm |
| Language: | English |
| Abstract: | The purpose of the study is to investigate whether experienced workers are as reliable and valid as professional expertise in evaluating lifting tasks on self perceived and actual perceived physical exertion. Linguistic approach was used in the evaluation. Three lifting tasks variables; weight of load, frequency of lift and duration of work were linguistically described in three levels. Fifteen male workers with various experiences in manual material handling and fifteen health care professionals were recruited in the present study. The reliability of the evaluation was tested by asking the subjects to conduct the evaluation twice separated by one-week period. The validity of the subjects' evaluation were cross-examined from three perspectives: 1) examination of the physical meaning of the lifting linguistic descriptors with the published norms; 2) cross-validation with the NIOSH lifting equation; and 3) investigation the relationships between perceived evaluation and the actual exertion in which the subjects were asked to actually perform the lifting tasks and determine the numerical values of each of the linguistic descriptors. Results indicated a moderate to high level of reliability in the interpretation of the linguistic descriptors of lifting variables (ICC (1,1) value of 0.71 and 0.61 for workers and health care professionals respectively). The reliability of self perceive dexertion on 27 combination of lifting tasks showed a similar trends (of 0.57 and 0.50 for workers and health care professionals). The mapping with the self perceived and actual perceived physical meanings of lifting tasks parameters showed that in the evaluation of 'moderate' and 'light' weight of load, both groups tend to over estimate the heaviness of the weight during perceived evaluation. The actual perceived 'heavy' weight of load and interpretation of frequency of lift by actual performance were within the ranges of perceived value in workers and health care professionals. Cross validation with the self perceived exertion with the NIOSH lifting equation revealed that, the rating of perceived exertion (RPE) at level 0 to 3 ("nothing at all" to"moderate" categorical levels) corresponds to lifting index (LI) of less than 1; level 3 to 5.5 ("moderate" to "hard") corresponds to 1<LI<=2; and level 5.5 to 8 ("hard" to"very hard") corresponds to 2<LI<=3. Workers perceived less exertion than health care professionals in the corresponding 1<LI<=2, and 2<LI<=3 ('nothing at all' to 'very weak', and 'very weak' to 'hard' respectively) in the actual lifting performance. Linear regression analyses revealed that the perceived evaluation was significantly related to the actual physical performance (r2 = 0.85-0.96 for the determination of numerical value of the linguistic descriptors, and r2 = 0.68-0.96 inthe evaluation of effort associated with the lifting activities). The study provides evidence that workers are reliable in predicting the perceived exertion on lifting tasks and their evaluation are as good as health care professionals. The linguistic approach used in this study capitalized the knowledge and expertise of workers. The worker's perceived physical exertion can be used as a valuable tool to identify the lifting tasks problems. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b16590053.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 7.71 MB | Adobe PDF | View/Open |
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