Seyyed Ali Moussavi-Najarkola AJE Vol.9 2009
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Table 10. Elements for determining the multiplier factor for effective items EI
Score of effective items 0 1-4 5-8
9-12 12
Multiplier factor 1 1.5 2 2.5 3
4.1. Applicability of the CEI
The proposed CEI model has been applied successfully in several studies performed by the author unpublished reports; this success shows that it can be
used in the study of many repetitive single or multiple tasks without any limitations. In most cases the aim of studies has been to identify and assess the risk factors of
UEMSDs and injuries for individual employees. A more detailed and general purpose was to assay, measure and investigate the reliability and validity of various
survey risk factors involving in calculating the CEI Score. The studies have been performed in different fields, including weaving and textile industries,
manufacturing industries, carpentry, steel industry, post offices, service industry, electronic industry, shopping and marketing, agriculture and farming industry,
tailoring and sewing, hair styling, baking, and bricklaying.
4.1. Applicability of the CEI
The proposed CEI model has been applied successfully in several studies performed by the author unpublished reports; this success shows that it can be
used in the study of many repetitive single or multiple tasks without any limitations. In most cases the aim of studies has been to identify and assess the risk factors of
UEMSDs and injuries for individual employees. A more detailed and general purpose was to assay, measure and investigate the reliability and validity of various
survey risk factors involving in calculating the
4.2. Reliability and validity tests of the CEI 4.2.1. Inter-observer reliability test of the assessment items
Inter-observer assessment reliability Table 11 was assessed to identify possible sources of error in the reliability assessment test process. In this test, 31 various tasks
were randomly selected from 31 different jobs involving manual handling tasks with varied part load weights. The ergonomic field study assessed static and
repetitive tasks; highly repetitive tasks; repetitive tasks with low, moderate and high force exertions; sedentary or standing tasks; and non- repetitive tasks with low,
moderate and high force exertions. Video-tape recordings were viewed in slow motion to confirm the assessment of the observer. Several pilot tests quantified that
assessment durations of 5-7 minutes are sufficient to complete the assessment