Motion capturing is a promising method to assess working postures and human movements and, therewith, the risk of musculoskeletal injuries that could occur while performing manual tasks in industrial settings. To obtain a reliable risk assessment, the motion capture system used has to accurately measure body postures adopted by the worker during the task. This study evaluates the accuracy to measure joint angles of upper extremities of two different motion capture systems, namely the Microsoft Kinect V2 and the Captiv system, for angles of upper extremities. For this purpose, an experimental study was conducted involving 12 subjects performing preset static postures and basic movements, including elbow flexion, shoulder flexion, and shoulder abduction. In addition, to examine whether self‐occlusion or occlusion of body parts by work equipment has an impact on the accuracy of the Kinect V2, the subjects handled boxes during some of the tests. As a gold standard, a goniometer for static and an angle scale for dynamic exercises was used. The Captiv system shows high correlation coefficients (r > .93) and small mean absolute errors (<5°) for all movements except for elbow flexion. The Kinect V2 has sufficient results for joint angles captured without occlusion as well, but the accuracy significantly decreases when occlusion occurs.
Quantitative and qualitative knowledge of ergonomic analysis of grapevines pruning and wine harvesting with respect to postural load, repetitive movements of cutting hand and using different cutting tools was obtained. It could be demonstrated, that stress generated by working postures and repetitive movements combined with were a major problem of work., Ergonomic design deficits of the existing cutting hand tools was carried out.
Even in hi-tech industries, physical workload is partly considerable and cannot be avoided because of product and process requirements. Especially in automotive, aviation, and marine industries, the assembly of the product geometry requires force exertions in ergonomically unfavorable conditions. Unfortunately, internationally accepted methods for the evaluation of those types of force exertions are rare. Besides some traditional German methods and EN 1005-3 hardly any evaluation methods exist. Even those methods refer to force exertions in primarily upright symmetric working postures. To overcome these problems the Assembly Specific Fore Atlas was created during the recent years. From a sample of automotive workers (n = 273), a set of 54 whole-body forces (6 main force directions while standing, sitting, kneeling; in an upward, bent, and overhead posture) and a set of 38 types of finger-hand forces (all at maximum voluntary contractions [MVC] levels) were measured in the field. The inputs for the types of force exertions required in practice were sampled from a consortium of major European car and truck companies. In addition, evaluation methods were developed that allow "calculating" maximum recommended force limits from the measured maximum static forces (i.e., MVC) and task and user group relevant parameters. This contribution gives a short overview on the data collected and focuses on the evaluation methods that had been realized. First, qualitative results are presented from the first field tests. C 2014 Wiley Periodicals, Inc.
Non-power and power cutting hand tools are mainly used every day in vineyards for grapevines pruning during 5 months (November - March). The grapevines pruning with the help of non-power tools is very stressful for wine growers. Repetitive movements combined with external forces in finger-hand-wrist-system, extreme positions in arm-shoulder-system, climate condition are some of the stress factors. Grapevines pruning with 5 manual prunes produced by 3 different manufacture and 2 power hand tools (electrically and pneumatically) were analysed. The results reveal that grapevines pruning with pneumatic and electric prunes is up to 30% more effective (according to productivity) than cutting with non-powered hand tools. At the same time is grapevines cutting with power tools more stressful as with non-powered one.
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