Application of the Strain Index in multiple task jobs.
Six different methods to calculate the Strain Index (SI) scores for jobs with multiple forces/tasks were developed. Exposure data of 733 subjects from 12 different worksites were used to calculate these SI scores. Results show that using different SI computation methods could result in different SI scores, hence different risk level classifications. However, some simpler methods generated SI scores were comparable to the more complicated composite SI method. Despite differences in the scores between the six different SI computation methods, Spearman rank-order correlation coefficients of 0.61-0.97 were found between the methods. With some confidence, ergonomic practitioners may use simpler methods, depending on their specificity requirement in job evaluations and available resources. Some SI computation methods may tend to over-estimate job risk levels, while others may tend to under-estimate job risk levels, due to different ways used in obtaining the various SI parameters and computations.
Bao
Stephen
S
Safety and Health Assessment and Research for Prevention (SHARP) Program, Washington State Department of Labor and Industries, Olympia, WA 98504, USA. baos235@lni.wa.gov
Spielholz
Peregrin
P
Howard
Ninica
N
Silverstein
Barbara
B
D000293:Adolescent; D000328:Adult; D001132:Arm / Q000473:pathology*; D001134:Arm Injuries / Q000175:diagnosis / Q000209:etiology; D012090:Cumulative Trauma Disorders / Q000175:diagnosis / Q000209:etiology*; D006804:Ergonomics; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000175:diagnosis / Q000209:etiology*; D009141:Musculoskeletal System / Q000293:injuries*; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D011187:Posture; D011446:Prospective Studies; D018570:Risk Assessment; D013995:Time; D055815:Young Adult