This paper introduces the Estonian Musculoskeletal Disorders Questionnaire (EMDQ), a practice-oriented tool for assessing the prevalence of musculoskeletal disorders in the workplace. Work-related musculoskeletal disorders (WMSDs) are an occupational health concern. Prevention largely depends on workstation-level interventions, where monitoring musculoskeletal discomfort helps set priorities. Although several tools like Nordic Musculoskeletal Questionnaire (NMQ) and the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) exist for mapping WMSD prevalence, they often face usability challenges for both workers completing the questionnaires and occupational health and safety (OHS) specialists analyzing the data. The EMDQ is designed to address these issues. Available in both paper and electronic formats, it features a gender-neutral body map that divides the body into distinct regions, supporting inclusive dissemination among workers. The questionnaire is intentionally brief to minimize worker effort. For OHS specialists, the EMDQ enables automated data processing that: (1) visualizes the most affected body regions, (2) estimates prevalence within the sample and extrapolates to the entire workforce, and (3) compares company-level data with sectoral averages. Additionally, the EMDQ includes guidance to ensure compliance with GDPR, supporting ethical data handling practices.

The aim of this study was to compare seat pressure asymmetries before and after 30 min cycling at constant intensity in association with pelvic anthropometric parameters and skeletal muscle fatigue. Twelve male road cyclists aged 18–30 years (mean training experience 9.9 ± 2.5 years) participated. Pelvic anthropometric data and body composition were measured with dual-energy X-ray absorptiometry. Participants performed 30 min cycling at 50% peak power output at constant intensity on a cyclus-2 ergometer. Muscle fatigue during cycling was assessed by surface electromyogram spectral mean power frequency (MPF) for the back, gluteal, and thigh muscles. The pressure mapping system was used to assess sitting symmetry before and after the cycling exercise. At the end of cycling, MPF was decreased (p < 0.05) in the dominant side’s erector spinae muscle and the contralateral gluteal muscle. After the exercise, a significant (p < 0.05) asymmetry in seat pressure was observed under the ischial tuberosity based on the peak pressure right to left ratio, whereas peak pressure decreased under the left ischial tuberosity. After the exercise, the relationship (p < 0.05) between pelvis width and pressure under the ischial tuberosity occurred on the dominant side of the body. In conclusion, an asymmetry was revealed after the constant-load cycling exercise by peak pressure ratio right to left side. Further studies should address the role of seat pressure asymmetries before and after cycling exercises at different intensities and durations.

Background: Prolonged sitting posture and sedentary behaviour, spent mostly in sitting are harmful for general health. The low back and shoulder area are the most vulnerable. In these regions the sEMG registration of neuromuscular activity shows low activity in steady postures. Stiffness of according muscle can be measured by myotonometry. We were not able to find any direct comparison between these parameters although separately, direct correlations between contraction force and sEMG or stiffness have been clearly established. Research question: Whether and how stiffness is modulated by neuromuscular activity in standing, lying or in different sitting postures in these vulnerable regions. Methods: The muscle's biomechanical stiffness (measured with MyotonPRO) and mean power frequency (MPF) with amplitude (AMP) on surface electromyography (sEMG) were registered in the upper part of musculus trapezius (UT) and musculus erector spinae (ES, at the level of L4 vertebrae). Nine healthy physically active males aged 19 to 46 (mean±SD, 28.6±10.9 years), participated in the study. The standing, prone, and three sitting postures where studied. The latter were distinguished by the back-tight-angle (BTA): 1) sitting on a common chair, straight back, BTA 90 deg), 2) slumped sitting on the same chair (BTA<90 deg), and 3) sitting on an experimental chair with a convex base, BTA 115-120 deg. Results and Significance: Muscle stiffness did not correlate with either of the sEMG parameters in ES but did so only in low grade with the AMP in UT (Spearman rank ρ=0.24, p=0.02). It was interesting that contrary to UT, in ES a significant positive correlation (ρ=0.24, p=0.02) was noted between MPF and AMP. It is likely that the steady body position under the Earth's g force may be ensured by the biomechanical characteristics of the tissue rather than neuromuscular activity. This can be explained by incompressible nature of soft tissues and be a less resource-consuming strategy. ### Competing Interest Statement The authors have declared no competing interest.

With depleting resources, it is essential to increase the application of Agriculture 4.0 principles and technologies. Blueberry cultivation includes various operations, one of them being fertilization. To precisely discharge the correct amount of fertilizer, a volumetric dispenser utilizing a straight fluted roller could be considered as an option. The aim of this research is to verify whether such a dispenser could be used for precision fertilization with solid granular fertilizers. The output of the dispenser was measured on different conditions with three NPK fertilizers. Based on statistical analysis, the required 10% discharge uniformity cannot be achieved and it is necessary to modify the dispenser or use another one.

This paper investigates the potential of using a low-cost microcontroller based system to monitor the lumbar flexion-relaxation phenomenon in the erector spinae muscle. A BITalino microcontroller was interfaced with an electromyography sensor and accelerometers. The data was combined in Matlab. The results indicate that the system is capable of visually demonstrating the presence of the lumbar flexionrelaxation phenomenon.

In order to function effectively, enterprises need to define various fields of their activity [1], [2]. This includes safety criteria and the satisfaction of safety-related needs of their workers [3]. Occupational safety should be seen as a set of working conditions that enable workers to operate safely. Such conditions are defined with reference to hazards and strains associated with ergonomic risk factors. Their identification is vital for meeting employee needs and expectations [4]. An effort to ensure them should be viewed as critical for competitiveness, leading to advantageous contracts. Many benefits are a direct consequence of the trust earned by enterprises that successfully shield themselves and their partners from losses precipitated by safety deficiencies. The article attempts to find ways to employ the network thinking methodology to identify ergonomic risk factors and thus essentially contribute to improving occupational safety by mitigating ergonomic hazards.

Objective: The aim of this study was to evaluate the ergonomic benefits of an angle grinder with a rotatable main handle in a cutting task. Background: Angle grinder manufacturers rarely address ergonomic features in their advertisements, and if they do, the benefits are expressed in a qualitative manner. Meanwhile, quantitative information about the effects of the device on the worker is required to make informed decisions during tool selection and cumulative trauma prevention. Method: Eleven maintenance workers and metalworkers used an angle grinder to cut a horizontal steel rod using three wrist postures. Only one of the postures was exclusively available in the case of a rotatable main handle. The postural effect was evaluated objectively with electromyography and a force-sensing-resistor-based force glove. Subjective ratings about discomfort and control were obtained with a visual analog scale. Results: The subjective ratings favor the near-neutral wrist posture. The forearm muscles' electromyographic activities were similar across the postures. Forces on the hand-handle interface were concentrated on the intermediate phalanges. If the device is operated without gloves, the forces on the intermediate phalanges may exceed the discomfort pressure threshold regardless of wrist posture. Conclusion: In the cutting task, the subjective measures favor the posture with a near-neutral wrist, which is a feature of the rotatable main handle. The objective measures did not allow one to prefer one posture to another. Application: The findings give insight into the impact of wrist posture on muscle activity, forces on the hand-handle interface, and discomfort. This is useful information for the person responsible for tool selection.

Background and objectives: Functional electrical stimulation (FES) has shown good results in improving static and dynamic sitting balance in persons with spinal cord injuries. There is limited information about how regular surface FES combined with therapeutic exercise (TE) affect dynamic sitting balance and muscle tone. The objective of this study was to evaluate the effectiveness of a six-week physical therapy program consisting of FES and TE on muscle tone and sitting balance in persons with spinal cord injury (SCI). It was also important to explore the relationship between muscle tone and dynamic sitting balance. The third objective was to assess the change of characteristics over a six month period, when no intervention was carried out. Material and methods: Five men with SCI were alternately allocated to two study groups: SCI_FES+TE and SCI_TE. Eight healthy control group participants were recruited to collect reference data. SCI participants' intervention lasted for six weeks in their homes. SCI_FES+TE conducted exercises with FES applied on erector spinae (ES) and rectus abdominis (RA) muscles. SCI_TE conducted exercises only. Muscle oscillation frequency (MOF; characterizing muscle tone) and limits of stability (LOS; characterizing sitting balance) were measured. A crossover study design was used. The time between the initial intervention and the crossover was seven months (ClinicalTrials registration ID NCT03517787). Results: MOF in SCI_FES+TE increased by 6.0% for ES and 6.1% for RA muscles. LOS of flexion increased 30.1% in SCI_FES+TE. Increase in lateral directions was similar for both study groups. Moderate to high negative correlation was found between MOF and LOS. After seven months, MOF of ES decreased 0.8%, MOF or RA decreased 1.4%, LOS of flexion decreased 31.9%, and LOS of lateral flexion to the left decreased 46.4%. Conclusions: The six-week therapy program combining FES and TE increased trunk muscle tone and dynamic sitting balance in flexion more than TE alone. Higher antagonist muscle tone negatively affects dynamic sitting balance and center of pressure (COP) trajectory distance in various directions. After seven months, a slight decline in trunk muscles tone values and an extensive decrease in sitting balance values were noticed.

IntroductionNoise-induced hearing loss is one of the most common health problems among military service personnel. Exposure to noise in military vehicles constitutes a large proportion of total noise exposure. This pilot study aimed to evaluate in-vehicle noise levels depending on the type of vehicle, riding compartment and road surface.MethodNoise levels were measured in armoured personnel carriers and heavy all-terrain trucks, in the cab and rear passenger compartment, while driving on paved or off-road surfaces. The results were compared with national LLV and allowed noise exposure times were calculated per vehicle and surface.ResultsThe equivalent noise levels in the cab of SISU XA-188 (p=0.001) and peak noise levels in MAN 4620 (p=0.0001) and DAF 4440 (p=0.0047) were higher on paved road, compared with off-road. The equivalent noise levels in the canvas covered rear compartment of MAN 4620 were significantly higher than in the cab on both paved (p=0.004) and off-road (p=0.0003). Peak noise levels in the cab of DAF 4440 exceeded the parameters measured in the canvas covered rear compartment on both paved (p=0.002) and off-road (p=0.0002). In most cases, peak noise levels were below the LLV (p=0.02–0.0001). The maximum noise exposure to passengers in the canvas covered rear compartment of MAN 4620 despite road surface was calculated 0.6 hours per working day.ConclusionA high risk of noise-induced hearing loss among military personnel occurs during long distance transportation with vehicles showing noise levels higher than allowed LLV.

This electromyographic field study investigates the need for several different ways to normalize the myoelectric activity of forearm muscles. The normalization procedure must allow for reliable comparisons between subjects, muscles and study conditions. Therefore, the contractions used for normalization have essential role in the interpretation of the results. Meanwhile, normalization in different postures increases temporal demands. In the study, five different normalization procedures were compared; three procedures involved squeezing the hand tool's handle, one squeezing a dynamometer and the last one consisted of resisting self-induced wrist flexion or extension. The results of the study group (n = 10) showed no need for normalization in handle specific postures. Based on the results, resisting investigator- or self-induced wrist flexion or extension is the preferred way to carry out forearm EMG normalizations in the field.

This paper focuses specifically on the hardware that could be used to assist in the prevention of upper-limb musculoskeletal disorders in the working environment. It lists the types of sensors that can be used to construct application for the measurement of force excretion, posture and repetitive movements. The paper presents the criteria to evaluate such applications, discusses the intrinsic properties of the applications, highlights the major restrictions to utilize the applications and proposes further needs of development, which are necessary to improve the quality of low-cost hardware assisted ergonomic evaluations.

Medical students can learn new knowledge and train technical skills by using simulations. Because the most of simulators are expensive the use of them is limited. The aim of this study is to design new low cost simulator for young veterinarians and surgeons. The simulator corpus has been designed based on the Solid Edge software and printed out with the 3D printer. For monitoring of the results we designed and programmed four exercises using the Arduino software. The monitoring of results is important for students to control the results. Needle suture, camera navigation, hand-hand coordination and tissue cutting are the main exercises for training of student skills. The purpose of simulation training also to increase the pace of skilled movements during simulation sessions, although the duration of every exercise is different. It is important to pay attention to ergonomics too in the designing process. The new simulator has mobile stand for different exercises to train technical skills in different ergonomic postures.

For decades, surface electromyography (sEMG) has been one of the essential methods of Human Factors and Ergonomics. Although capturing sEMG data is relatively easy, proper interpretation of acquired data is possible only with sufficient background in electrophysiology, muscle mechanics and muscle functions. As the last decade has made biosignal acquisition more accessible, the current overview discusses the intrinsic properties of contemporary low-cost sEMG acquisition systems and proposes applications of sEMG for Human Factors and Ergonomics.

This study was conducted in order to assess the potential of low-cost surface electromyography (sEMG) measurement systems to be applied in ergonomics practice on the example of provided relative grip force estimates. Two measurement configurations, with a total cost below $100, were compared with a commercially available electromyograph. It was hypothesized that Arduino based do-it-yourself measurement systems do not perform significantly worse than commercially available electromyograph. Ten participants’ normalized sEMG activity of the m. flexor digitorum superficialis were compared in the case of three submaximal isometric hand grip force levels (25%, 50%, 75% of maximum voluntary contraction). Normalized sEMG activity, measured with different systems, was not statistically different. It was concluded that low-cost measurement systems have the potential to be used in order to detect muscle activation-deactivation patterns or at least the semi-quantitative assessment of grip force; however, the results of this study are limited to isometric contractions.

Many ergonomic studies deal with comfort or try to find optimal parameters for tool design. Most of these studies also emphasise the importance of coupling between hand and handle. In order to collect objective data about hand -handle interface pressure, tactile sensors can be used. A trade-off between sensor dimensions, sensel density, robustness, and accuracy must be considered while choosing between commercial tactile sensors for ergonomic investigations. Based on literature from the last two decades, the main aspects of tactile sensors usage are highlighted.

Noise is known as an irritant both in industrial and living space settings. Also the negative effect of noise on people's health and wellbeing is widely recognised. Usually in the work environment the impact of noise can be easily reduced, for example, by providing personal protective equipment or using the appropriate administrative tools. However, in residential areas near by to industry, the problem is quite different. Although the population density in Estonia is quite low compared to other European countries, there are rural areas where industrial noise sources are located nearby to people's homes. Also the awareness of noise hazard is rising among people, and company owners are forced to diminish the noise levels of production. This generates a need for knowledge about noise reduction. Current study aims to compile data about the noise emission of grain dryers with main concern towards noise direction. Results of the study can be applied in developing layouts of grain dryers or in noise barrier development. Noise levels around the perimeters of different type grain dryers were measured with a TES- 1358A sound analyser in 1/3 octave band segregation. Measurement data was compiled into noise maps. Specifications of Estonian laws were taken into account.

In spite of a dominant trend towards free-range milking systems there is still a significant amount of tethered milking systems used in Estonian farms. As people become more accustomed with welfare society, it is hard to find employees for tethered milking systems. Thus, the user friendliness and also the sustainability of workforce become more and more valuable. Therefore, ergonomic criteria must be considered while choosing milking machines or replacing one machine with another. The aim of the study is to serve as a methodical guide for assessment of ergonomic quality of milking machines. In the study, the usability of various ergonomic methods was tested to assess the milking machines. All the tests were conducted in the laboratory (a pipeline test rig) conditions. As a result, usable methods with suggestions where selected.

The object of the study was heating pump Booster SP and indoor climate provided by floor and ventilation heating. The test site, laboratory of ‘Heating pumps and indoor climate’, was in The Estonian University of Life Sciences Institute of Technology. Heating pump together with ventilation system were set to automatically ensure proper indoor climate. The particularities of the laboratory setting are the alternative depth of the ground collector (1.5 m) and two indoor heating contours with different layouts. The operating parameters of heating pump were measured by thermocouple probes which were placed on the nodes of heating pump. Indoor climate, provided by heating pump Booster SP and ventilation system, was assessed with a diagnostics device which sensors were placed 1.5 m from the floor. The operating state of ground contour, two indoor heating contours, heating pump and indoor climate was diagnosed by simultaneous data accusation. Based on data processing the operating state and efficiency of heating pump, indoor climate’s compliance with laws and legislations was assessed

Earlier studies have indicated that elevated or inadequate levels of carbon dioxide (CO2) in indoor air impairs users in the performance of decision-making. For this reason and also for potential energy consumption reduction carbon dioxide based regulated demand controlled ventilation (DCV) systems are used. Although DCV systems use less electrical energy than conventional ventilation systems, there is a problem in colder climates with the lowered humidity of air. It has been discovered in earlier studies that even brief exposure to relatively dry air has an impact on voice control parameters. In the current article, the humidity gains from ordinary usage of a faculty building, where a DCV system and room based temperature control is utilised, are examined. For that, the changes in the specific indoor humidity were compared to the changes in the specific ambient humidity.