Timber harvest operations in a Pinus taeda thinning require a few different postures by machine operators that could be harmful to their health. This research aimed to analyze the upper limb posture of the operators in two harvester models, a tracked versus wheeled harvester in thinning of Pinus taeda stands, to identify possible issues and propose ergonomic solutions. The postural analysis was conducted in thinning operations, by filming the operators at their workstations. Posture evaluations were performed by the Rapid Upper-Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) methods and analyzed the outcomes by factorial analysis. Results showed that the operators stayed for a long time in the static sitting posture and with operational repetitive movements, worsened by the absence of recovery work breaks, with significant statistical differences for the two machines evaluated. For the tracked harvester, 15 typical postures were identified, and in 91% and 92% of the workday, the operator had their trunk and head inclined, respectively. For the wheeled harvester, only eight typical postures were identified, and in 12% and 50% of the time, the operatorremained with their trunk and head tilted. Finally, we were able to observe that tracked harvester operators spent more time on postures ergonomically harmful, with higher action level measures needed. The wheeled harvester provided the best working conditions in terms of posture and repetitiveness, making it the most ergonomically suitable machine.

The levels of exposure whole-body vibration (WBV) while performing mechanized soil preparation operations are concerning due to the exposure time of operators at their work stations, adverse terrain topography, and types of wheels on the machines used. Thus, this study aimed to evaluate the exposure to WBV in bulldozers and hydraulic excavators in performing soil preparation for forest plantation in order to identify possible ergonomic problems and propose improvements in working conditions. The study was carried out in Paraná State, Brazil, in a Eucalyptus urophylla × Eucalyptus grandis stand hybrid, being registered with use of a vibration meter and triaxial accelerometer coupled to the seat of the machines, the resulting acceleration to normalized exposure (aren) and the resulting vibration dose (VDVR) for a period of 8 working hours, following the Occupational Hygiene Standard 09. The results showed aren and VDVR values of 1.0 m s-2 and 18.3 m s-1.75 in the bulldozer, while in the hydraulic excavator it was 0.7 m s-2 and 13.5 m s-1.75, respectively, with a statistically significant difference between the machines by the Wilcoxon test for independent samples (α ≤ 0.05). The WBV levels were above the action level and below the exposure limit in both machines, with the bulldozer showing values above the uncertainty level. Therefore, substituting machines specifically designed for soil preparation and improvements in work organization are measures indicated to reduce ergonomic problems.

In mechanized timber harvesting operations, it is possible to verify ergonomic inadequacies, such as poor visibility and inappropriate postures, which can cause risks to the safety and health of workers, with effects on the operational performance of the machines. In this context, the objective of this work was to evaluate the effects of the positioning of the coupling crane in harvesters concerning the visibility and postures of forestry operators. For this, the study was carried out in clear-cutting operations in eucalyptus stands, evaluating a harvester with a frontal coupling crane and another with lateral coupling, as well as operators per machine. To determine effective times and typical postures, filming and freezing of images were performed. Then, the Skogforsk and Rapid Upper-Limb Assessment (RULA) methods were used to assess visibility and posture, respectively. Angulation and posture data were compared between machines by the Student's t test. Front and side visibility remained within acceptable limits, but the side crane harvester required operators to have an average head tilt angle of 15º, 50% higher than with the front crane. Consequently, in the postural evaluation, the one with the lateral crane presented score 3 and action level 2 86% of the time, suggesting further investigations, while the other presented score 2 and action level 1 81% of the time, being acceptable if not maintained or repeated for long periods. Therefore, the positioning of the crane coupling on the machine requires a reorganization of the workstation, mainly the machine's display.

Mechanization in timber harvesting has improved the comfort and safety of operator workstations. However, there is an imminent ergonomic risk in relation to the repetition of movements, which can cause musculoskeletal injuries. The aim of this study was to apply infrared thermography to identify musculoskeletal overload in the hand region of harvester operators. This study was conducted on wood harvesting of homogeneous Eucalyptus urophylla × Eucalyptus grandis stands using a forestry harvester tractor. Thermographic images were taken of seven operators at the beginning and end of the working day during six days of the shift. The maximum, average, and minimum temperatures were measured in 14 hand regions of interest (ROI), verifying the existence of a difference between the beginning and the end of work (p-value < 5%) by using the Mann–Whitney test. The operators presented hyperradiant temperature variation in the hand region after work, with a variation above 2.5 °C, indicating a high degree of abnormality. There was greater temperature variation in the right hand (3.7 °C) due to the greater concentration of commands on the machine’s right joystick. Infrared thermography has proven to be an important tool for functional imaging diagnosis, contributing to the reduction in risks of developing Repetitive Strain Injury/Work-Related Musculoskeletal Disorder (RSI-WMSD).

No Brasil, pouco são os estudos relacionados a exposição ocupacional à vibração de corpo inteiro em postos de trabalho de máquinas florestais e, quando consideradas operações de desbaste, não há estudos relacionados. Este estudo foi realizado na região de Bituruna-Pr, em povoamentos de pinus taeda com 10 anos de idade submetidos ao primeiro desbaste, objetivando quantificar os níveis de vibração a que estão expostos os operadores de dois tipos de harvester – esteiras e pneus – durante a jornada de trabalho. Utilizou-se um medidor integrador triaxial Bruel e kjaer modelo Type 4447 e os resultados analisados conforme os critérios estabelecidos pela NHO 09. O harvester de esteiras apresentou resultados de aren e VDVR equivalentes a 0,6 m/s² e 11,2 m/s1,75 respectivamente, enquanto o harvester de pneus apresentou valores médios de 0,4 m/s² e 9,3 m/s1,75. Os resultados indicaram diferenças significativas pelo teste t (p

Para aumentar a produtividade, empresas florestais brasileiras têm adotado o trabalho em turnos, incluindo operações noturnas, muitas vezes sem compreender plenamente os riscos ergonômicos em condições reais de operação. Este estudo avaliou o efeito dos turnos de trabalho sobre variáveis ergonômicas em postos de trabalho de máquinas, em povoamentos de eucalipto na região Sul do Brasil. Os dados foram coletados durante operações de corte, extração e processamento da madeira, utilizando feller buncher, grapple skidder e processador harvester, nos turnos diurno e noturno. A vibração de corpo inteiro foi avaliada conforme a NHO 09, o ruído e o conforto térmico com base nas NR 15 e NR 17, e a visibilidade segundo a diretriz ergonômica da Skogforsk, com comparação aos limites da legislação brasileira. Os resultados mostraram que os riscos ergonômicos foram mais influenciados pelo tipo de máquina e pelas condições operacionais do que pelo turno isoladamente. Diferenças entre turnos estiveram relacionadas a variações na condução da máquina, influenciadas pela visibilidade, velocidade de deslocamento e condições do terreno. O grappler skidder apresentou as condições mais críticas, com vibração de até 1,62 m/s² e ruído de até 89 dB(A), acima dos limites recomendados. Além disso, maiores movimentos laterais da cabeça indicaram redução da visibilidade, especialmente à noite. Conclui-se que os riscos ergonômicos na colheita mecanizada da madeira são determinados principalmente pelas exigências operacionais, reforçando a necessidade de melhorias no projeto das máquinas, na manutenção e na organização do trabalho.