The Repetitive Strain Injury / Wo rk Related Musculoskeletal Disorders (LER / DORT) can arise in any field of ac tivity; just there is a causal factor, ie, functions and jobs that expose workers to risk factors. These risk factors are present in t he operator of the harvesti ng machinery activities. Throughout the workday upper limbs are highly required, necessitating the execution of repetitiv e movements at high speed and asymmetric postures, which leads to muscle overload. The work organization, psychosocial factors and the inadequacie s of the jobs ar e pointed out as responsible for cases of LER/DORT . Despite the evidence that LER/ DORT can affect the harvesting machine operators, in the country there is a lack of researches results of resear ch conducting it can be inferred, consistently, about the relationship between LER / DORT and the activities of operators of harvesting machinery. Thus, became the interest in develop this research, which used as assessment parameters Normative INSS / DC N0 98 of December 05, 2003 - DOU of 10 /12/2003 that deals specifically with the LER / DORT. The study consisted in the cut-to-length system. The harvesting module used was harvester and forwarder. Initially we tried to determine the prevalence of musculoskeletal symptoms, using the standard Nordic questionnaire and the census of ergonomics. These tools are validated methodologies that aim to evaluate the musculoskeletal symptoms. Given the importance of organizational and psychosocial aspects of work in the genesis of LER / DORT, we tried to describe the risk factors linked to these aspects, through systematic observations, in situ, of the typical working day a nd through a questionnaire designed and developed for this study. Considering t he demands of the wrist joint in the activity of harvesting machine oper ators, muscle elec tromyographic and kinesiology analysis of this joint was performed. A Miotool electromyograph, model 400, has bee n used for the electromyographic analysis. The kinesiology analysis was done from on-site observations, photographic and film records. The Latko scale and the Silverstein criterion (1985) were also used. The results showed that the prevalence of musculoskeletal symptoms was high, reaching 62.9% of machine operators. In addition, work can have different impacts on workers exposed to the same working condit ions, which can be explained by psychosocial and organizational fact ors. It was possible to observe differences in electromyographic pattern s of flexor and extensor muscles, this factor may be indicative of muscle damage caused by the working time. The movements made by operator s during working hours are related to some disorders recognized as LER / DORT. Considering the risk factors present and properly investigated in the activity of the forest machines operator, it can be conclude d that this study is an indication that the tasks performed are exposing workers to a c onsiderable risk of acquiring LER / DORT.
