# A Review on Ergonomics in Agriculture. Part II: Mechanized Operations
## 5 Discussion
Generally, the effect of vibration exposure on operators strongly depends on its magnitude, duration, frequency and direction. However, most of the time, it is not easy to distinguish the effects of vibration from those originated from usual risk factors like prolonged awkward postures and intensive static postures. In other words, it is the interaction of improper long-term body postures and manual materials handling and vibration exposure that is responsible for the precipitation of MSDs. The wrong postures of trunk, arm and wrist may lead the muscles to be less tolerant to vibration stresses. Overexpression, owing to the poor matching of the equipment with the anthropometric characteristics of the operator, along with seat discomfort is also a key factor for developing or aggravating the experienced MSDs. Body posture ergonomics and WBV are well founded research fields in several occupational sectors. Nevertheless, the crossover area that covers both factors is less developed, especially in agriculture that is a labor-intensive field and occupies most of the working population worldwide. As a consequence, to advance the knowledge, experts' opinion from both areas as well as more systematic experimental and computational investigations is necessary. Modern design of agricultural machines is an interdisciplinary mission based on the state-of-the-art advances in ergonomics, biomechanics as well as structural mechanics. Overall, these design parameters should meet three criteria, namely comfort, health and safety of the operator. The comfort deals with the ergonomic considerations like seat and handle dimensions, cushioning materials and the perception of comfort of the operator. The health and safety correspond, for example, to the extended spinal support during operating a machinery with a seat and damping of vibrations. In a nutshell, taking also into account the results of the recent article regarding ergonomics in manual agricultural operations [7], low back pain was proved to be the major reported MSD. Rural workers are engaged in both manual and mechanized operations. Hence, concerted and systematic strategy is suggested with the intention of increasing the awareness of the related risk factors and designing of ergonomic equipment for protecting this body area. This strategy could be accomplished through international safety and health awareness programs by providing simple guidelines to workers for acquiring the less intensive posture for each agricultural machinery. More targeted effort is also required on the base of the anthropometric characteristics of each nation because improper equipment can cause additional MSDs. Frequent rest brakes can also be a viable solution in order to assist the viscoelastic connective tissues to recover from either repetitive fatigue [84] characterizing the manual tasks, such as harvesting and weeding, or vibration exposure [34]. Finally, the experience of the operators themselves will add a unique perspective since they are the most crucial members of this kind of surveys. Their contribution is paramount for developing sustainable ergonomic interventions by providing feedback on comfort and socio-cultural issues, which can influence their acceptance and adoption barriers. We still have a long way to make a safe agricultural environment, since the progress that has been made does not correspond to the gravity of this matter. Therefore, more collaborative efforts are required among physicians, ergonomists, engineers, manufacturers and international organizations concerning occupational health. _Study Strengths and Limitations_  
The main limitation of this study is considered to be the fact that non-English articles were not taken into account. Nevertheless, agriculture is regarded to be the main occupation of workers from developing countries who speak, for example, Spanish as well as African and Asian languages. In addition, papers published in journals with impact factor less than one were excluded, a factor that does not necessarily mirror the quality of single works.