Methodology of Physical Load Risk Assessment in Latvia
Authors: Kalkis Valdis , Roja Zenija , Kalkis Henrijs 
Published: February 2022

Occupational safety and health have a considerable value for employees and employers in Latvia. Despite the fact that modern production systems involve highly specialized and complex machinery, there are many human activities including manual tasks that have not been automated due to flexibility requirements. Physical overloading is caused, for example, by lifting or pushing heavy objects, daily use of vibratory tools or prolonged work while bending over. Insufficient physical load (lack of activities) is caused, for example, by prolonged sedentary work without periodic breaks for movement. The importance of psycho-emotional factors, including stress at work, should also be taken into account here. Musculoskeletal complaints are responsible for one-third of the reported cases of absenteeism and disability. Therefore, physical load forms the core of the problem, and is one of the main factors hindering sustained healthy, productive work, and wellbeing. This calls for the development of practical exposure assessment tools, particularly for health and safety practitioners, to quickly assess an exposure to ergonomic risks. The knowledge of the risk and corresponding risk assessment methods are aim of investigation and provide basis for the formulation and implementation of preventive measures. The road building workers, textile sewers and cutters, as well as fire-fighters-rescuers, who are employed in a wide range of tasks, were used as an example of ergonomic risk analysis.Several tools for description and assessment of ergonomic risks applying subjective, mathematical and experimental (objective) methods were used. The chosen tools and technique are: Extended Nordic Musculoskeletal Questionnaire (NMQ-E); KIM (exposure scores for pushing/pulling, carrying), QEC (exposure levels for main body regions), OWAS (time sampling for body postures and force), RULA (categorization of upper limb postures and force with action levels), MAC (manual handling assessment charts), NIOSH (lifting equations, biomechanical load limits), SI (the strain index), workload energy expenditure (WEE), heart rate monitoring (HRM), myotonometry (MYO), NASA-TLX (mental and physical workload interaction/task load index), WAI (work ability index). The chosen methods have been categorized under four main headings: 1) self-reports from workers, 2) observation methods, 3) mathematical methods, 4) direct measurement of exposure variables at work.Analysing these methods it was established that KIM, QEC, NIOSH, OWAS, WAI and HRM are more suitable for quick assessment of the ergonomic risks at work, while the RULA, WEE and MYO are more complicated for quick assessment. It was found that employee's subjective point of view on workload does not always coincide with the objective measurement results. It was concluded that the physical load assessment methods, analysed in this study, are successfully introduced in Latvia, and preventive measures, such as medical hypnotherapy, including cognitive hypnotherapy and self-hypnosis training sessions, are effective methods to decrease composite chronic pain intensity, as well as to decrease psychogenic tension and muscle fatigue, and to increase the life quality.