| Popis: |
Ergonomic assessments are used to determine the appropriate interventions to minimize the risk of musculoskeletal disorders. However, current ergonomic assessment methods for lower extremity musculoskeletal disorders (LE-MSDs) have several limitations. The main objective of the study was to develop a new instrument for assessing risk factors for LE-MSDs. Specifically, this instrument development effort was focused on LE-MSDs of the hip, knee, and foot/ankle using a three-phase process that included development, validity assessment, and reliability assessment. The development of the new assessment tool involved several steps, including literature searches, evidence assessment, a Delphi survey, and tool development. The first three steps were conducted to construct comprehensive lists of risk factors. The steps confirmed 16 risk factors for LE-MSDs in the hip, 27 risk factors for LE-MSDs in the knee, and 19 risk factors for LE-MSDs in the foot/ankle. The tool, LEAT (Lower extremity Ergonomics Assessment Tool), had 47 input questions that assess occupational and worker-specific factors that were determined based on the confirmed risk factors. Scoring tables for calculating risk assessment scores were also developed based on the confirmed risk factors. The outputs of the tool include both quantitative and qualitative indicators: LEAT scores, degree of risk, and explanation of the risk factor exposures found in the assessed jobs, or workers. The second phase was aimed at assessing the preliminary validity of the tool. Two epidemiological measures, namely the tool’s sensitivity and specificity, were utilized to determine the validity. The data were gathered by observing sixty-two full-time employees performing their jobs (to gather the needed input about the job factors in LEAT) and afterward interviewing them (to gather the needed input about worker-specific factors in LEAT). The results of the study revealed that the highest performance was observed when classifying jobs that posed risks associated with LE-MSDs in the knee. The lower performance was observed in the tool’s ability to classify jobs that posed risks associated with LE-MSDs in the hip. The lowest performance was seen in the lack of an association between the hazard classification from the tool and the morbidity classification of adverse outcomes in the foot/ankle. The assessment revealed a high prevalence of worker-specific factors such as high body mass index (BMI) and a history of lower extremity injuries. As such, there could be benefits to considering worker-specific/personal factors as assessed by the tool when attempting to reduce the risk of workers developing LE-MSDs or reducing the exacerbation of existing symptoms.The reliability, usefulness and usability of the tool were assessed as the last phase of the study. Data were obtained from seven tool user-participants who were employed in safety-related occupations from four job sites. Each participant performed ergonomic assessments utilizing the LEAT on jobs performed by two worker-participants within their organization. The researcher (AA) performed similar independent assessments, and those results were compared in a preliminary assessment of inter-rater reliability. At the end of the job site assessment, the tool user-participants were asked to complete a usefulness and usability survey, as well as to participate in a debriefing session. The results indicated that the reliability was subject to interpretations of the instrument’s questions. The questions that could lead to fewer interpretations were associated with higher reliability. This will be addressed through improvements to the user manual by refining descriptions and adding illustrations. The usefulness and usability assessment revealed several issues, most notably the difficulties in determining the exposure quantities of jobs with inconsistent duties. Possible solutions to overcome the issue include utilizing an activity monitoring system, which needs to be introduced in the tool description or the user manual. Furthermore, although most worker-participants indicated comfortable feelings answering questions that addressed worker-specific factors, the tool user-participants reported uncomfortable feelings asking about those factors, particularly body weight and medical history associated with LE-MSDs.The three phases of the study resulted in a new assessment tool for assessing risk factors associated with LE-MSDs for which the preliminary validity and reliability assessments of the tool were favorable but show that further development work is needed. With further development, the tool could be utilized to help occupational health and safety practitioners assess and limit exposures to risk factors associated with LE-MSDs. Furthermore, although the tool’s validity and reliability have been assessed, future work should include more extensive validity studies to further improve the tool. |
