The Key Indicator Method for Manual Handling Operations (KIM-MHO) - evaluation of a new method for the assessment of working conditions within a cross-sectional study

BACKGROUND: Upper extremity musculoskeletal symptoms and disorders are common in the working population. The economic and social impact of such disorders is considerable. Long-time, dynamic repetitive exposure of the hand-arm system during manual handling operations (MHO) alone or in combination with static and postural effort are recognised as causes of musculoskeletal symptoms and disorders. The assessment of these manual work tasks is crucial to estimate health risks of exposed employees. For these work tasks, a new method for the assessment of the working conditions was developed by the Federal Institute for Occupational Safety and Health (BAuA) and released as a draft in the year 2007. The draft of the so-called Key Indicator Method for Manual Handling Operations (KIM-MHO) was developed in analogy with the existing KIM for Lifting/Holding/Carrying (KIM-LHC) and Pulling/Pushing (KIM-PP) of loads. The KIM-MHO is designed to fill the gap existing in risk assessment of manual work processes, since the existing KIMs deal only with manual handling of loads. This research project focused on the following: - Examination of the validity of workplace assessment with the KIM-MHO comparing expert ratings with the results of the observations. - Examination of the objectivity of workplace assessment with the KIM-MHO applied by different examiners. - Examination of the criterion validity of the risk assessment provided by KIM-MHO with respect to the association between exposure and the occurrence and prevalence of health related outcomes. METHODS/DESIGN: To determine the objectivity and validity of workplace assessment, the KIM-MHO is applied by occupational health and safety officers at different workplaces involving manual handling operations. To determine the criterion validity of risk assessment, a survey of employees at different workplaces takes place with standardised questionnaires and interviews about symptoms in the neck and upper extremities. In addition, physical examinations of these employees following a standardised medical diagnostic procedure are also carried out. DISCUSSION: This research project will provide scientific evaluation of the new KIM-MHO and, if necessary, indicate areas for modification to improve this new method for assessment of the health risk of manual handling operations at diverse workplaces.