ObjectiveThis research work is dedicated to occupational health problems caused by ergonomic risks. The research object was road building industry, where workers have to work very intensively, have long work hours, are working in forced/constrained work postures and overstrain during the work specific parts of their bodies. The aim of this study was to evaluate the work heaviness degree and to estimate the muscle fatigue of workers after one week work cycle. The study group consisted of 10 road construction and maintenance workers and 10 pavers aged between 20 and 60 years.MethodsPhysical load were analyzed by measuring heart rate (HR), work postures (OWAS) and perceived exertion (RPE). Assessments of the muscles strain and functional state (tone) were carried out using myotonometric (MYO) measurements. The reliability of the statistical processing of heart rate monitoring and myotonometry data was determined using correlating analysis.ResultsThis study showed that that road construction and repairing works should be considered as a hard work according to average metabolic energy consumption 8.1 ± 1.5 kcal/min; paving, in its turn, was a moderately hard work according to 7.2 ± 1.1 kcal/min. Several muscle tone levels were identified allowing subdivision of workers into three conditional categories basing on muscle tone and fatigue: I – absolute muscle relaxation and ability to relax; II – a state of equilibrium, when muscles are able to adapt to the work load and are partly able to relax; and III – muscle fatigue and increased tone. It was also found out that the increase of muscle tone and fatigue mainly depend on workers physical preparedness and length of service, and less – on their age.ConclusionWe have concluded that a complex ergonomic analysis consisting of heart rate monitoring, assessment of compulsive working postures and myotonometry is appropriate to assess the work heaviness degree and can provide prognosis of occupational pathology or work-related musculoskeletal disorders for the workers under different workload conditions. These results can also be used when deciding on necessary rest time and its periodicity.

BackgroundProblems associated with pain in several body regions due to work-related musculoskeletal disorders (WRMDs), repetitive movement and negative stress at work are quite common in many manufacturing industries of Latvia, int.al. clothing industry. The aim of this study was to evaluate efficiency of the psychotherapeutic intervention using medical hypnotherapy (MH) program for mind-body relaxation with pain-blocking imagery, cognitive restructuring of unpleasant physical and emotional experience.Methods300 sewers and 50 cutters with chronic pain were involved in the study. Self-rated WRMDs symptoms, pain intensity and interference were assessed using the extended version of Nordic Musculoskeletal Questionnaire and Brief Pain Inventory Scale. Assessment of the functional state of muscles was carried out using myotonometric (MYO) measurements. Work heaviness degree was estimated via heart rate monitoring (HRM). The MH program was composed of cognitive hypnotherapy and self-hypnosis training. Sunnen Trance Scale was used to determine person’s hypnotic susceptibility. Life quality assessment before and after MH program was carried out using Quality of Life Scale.ResultsAt the beginning of MH program sessions both sewers and cutters reported on pain interference with general activities, mood, sleep, normal work, etc., but after MH the interference of pain significantly decreased. HRM data confirmed that work heaviness degree of sewers and cutters can be referred to as light and moderate work (energy expenditure for their tasks varies from 3.4 till 4.7 kcal/min). Using MYO measurements it was stated that before MH 22% of workers involved in the study fell under III MYO category indices, consequently, their muscle tone was increased, which is associated with muscular fatigue. After MH muscle tone remained within the normal range meaning that they were able to adapt to the existing workload (II MYO category) or fully relax (I MYO category).ConclusionsMH program including exercises-workouts, cognitive hypnotherapy and self-hypnosis training sessions is an effective method to decrease composite chronic pain intensity for sewers and cutters, as well as to decrease psychogenic tension and muscle fatigue (proved by objective measurements of muscles tone) and to increase the life quality.

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-Radiation crosslinking of polyolefins has gained interest for the development of advanced heat-shrinkable materials. Propylene homopolymer (PP1), polypropylenepolyethylene block copolymers (PP2, PP3) and their mixtures with 3 wt.% of bisphenol A dimethacrylate (BPDMA) crosslinking agent were irradiated with 25-150 kGy of accelerated electrons and were compared for aforementioned purpose. The studied mechanical properties indicated increased elongation in the presence of BPDMA that was contributed to the crosslinked moieties of PP and the crosslinking agent. The shrinkage stresses were comparable to that of polyethylene based heat-shrinkable material.

Assessment of firefighters-rescuers' work severity in relation with interaction between physical and mental load The present work is focused on occupational health problems caused by ergonomic risk in firefighting, which is one of the most hazardous occupations. The aim was to evaluate the work heaviness degree and to estimate the muscle fatigue for a study group consisting of 12 firefighters-rescuers. Applying qualitative ergonomic analyses (OWAS a.o.) and clinical experiments to determine consumed metabolic energy using heart rate monitoring, the following work hardness categories were observed: firefighter-rescuer — category III (hard work, 8.2 ± 1.2 kcal/min); commanding officers — category II (moderate work, 6.0 ± 1.6 kcal/min). Assessment of muscle strain and functional state (tone) using myotonometric measurements showed several muscle tone levels, allowing subdivision of firefighters into different conditional categories basing on muscle tone and fatigue: I — a state of equilibrium when muscles are able to adapt to the work load and are partly able to relax; and II — muscle fatigue and increased tone. It was also found that the increase of muscle tone and fatigue mainly depended on workers physical preparedness and length of service, and less on their age. Assessment interaction of mental and physical load using NASA-TLX method indicated that the highest degree of total workload was for several firemen, especially, commanding officers when temporary demands, task performance, effort and frustration were taken into consideration.

Abstract. In Latvia, the number of aging employees suffering from sleep disorders caused by job stress and poor sleep hygiene is increasing. The non-pharmacologic and pharmacologic treatment is prescribed for these employees in the sleep management. The aim of this research is to clarify the efficiency of using psychotherapy with learning and observing sleep hygiene, combined with the melatonergic drug during a six-week treatment course applied to 25 both male and female intellectual workers over 65 years suffering from insomnia caused by job stress. For the patients representing Group "A" cognitive hypnotherapy, intervention for improving coping with job stress and usage of the melatonergic drug was prescribed, while Group "B" patients received six weeks only drug. The severity of depressive episodes in employees was measured by MontgomeryÅsberg Depression Rating Scale, the level of anxiety was assessed by use Rosenberg SelfEsteem Scale. The results of the research show that insomnia patterns disappeared for 75% of women and 80% of men employees in Group A, but in Group B individuals, -only for 20% of women employees. The results acquired let concluding that the six-week treatment -cognitive hypnotherapy combined with melatonergic drug -is an effective treatment for aging workers suffering from sleep disorders.

Contemporary organisations have to search for new strategic ways in order to improve economic effectiveness and work productivity, as well as to maintain human resources in long term. Managers should ensure open management of changes in order to motivate employees to participate in it delegating more responsibility to employees. This can promote trust, support employees' initiatives in operations improvement thus changing traditional organizational structure to flexible operations management. Therefore combined approach of macro-and micro-ergonomics in strategic operations management can result in effective improvement of labour productivity, management of technologies and healthy work environment. The developed model "Ergonomics implementation in operations management", based on the overview of the recent prominent literature, shows that changes in operations management due to ergonomics implementation stimulate satisfaction of employees, increase productivity, and decrease costs resulting in an improvement of the process and product quality.

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