The development of a practical tool for risk assessment of manual work – the HAT-tool

For the Dutch Ministry of Social Affairs and Employment we developed a tool to assess the risks of developing complaints of the arm, neck or shoulders during manual work. The tool was developed for every type of organization and is easy to use, does not require measurements other than time and can be used without training or ergonomic expertise. With the tool, that was named ‘risk assessment Hand-Arm-Tasks’ (HAT-tool), risks are assessed on task level (instead of days or jobs) and on group level (instead of individual level). The procedure is comparable with the NIOSH-formula for lifting. In the first phase of the project we defined a set of criteria for the tool. Then, we made an overview of available methods and investigated which method(s) fitted best to the criteria. This appeared to be the Key Indicator Method for Manual Operations of Steinberg et al. (2007) which we used as a basis. We selected this method because its aims were very similar to ours. Then, we adjusted the tool to meet our criteria. We selected risk factors for arm, neck or shoulder complaints or disorders from the literature. The relative weight of these risk factors in the risk evaluation was based on both the literature and expert opinions. The risk factors that are included in the final version are: task duration and breaks, magnitude, duration and frequency of hand force, postures of head, neck, shoulder, arm and wrist, hand-arm vibration and ‘other risk factors’. Each risk factor gets a score, and together they add up to the overall risk score. With this score the task is evaluated to have ‘no increased risk’, ‘an increased risk’ or ‘a seriously increased risk’. A first prototype of the tool was tested in ten companies. With the results of this test we improved the tool. In the manual each step of the assessment is explained thoroughly. We are currently working on a validation study of the tool which will be ready at the end of 2008.