# A Review on Ergonomics in Agriculture. Part I: Manual Operations
## 1 Introduction  
Agriculture is considered to be the primary source of the supply of food worldwide as well as raw materials for industry and medicine. Moreover, taking into consideration the increasing global population and the consequent demand for food, certainly, agriculture constitutes the backbone of global economy. To that end, agriculture production has experienced a relatively high diffusion of advanced technologies including information systems [1], automated machinery systems [2], and even robotic systems that complement or substitute labor tasks [3]. However, as an occupational environment, regardless of these major technological advances, agriculture is regarded as one of the most demanding and hazardous sectors. As a matter of fact, it is ranked second among occupational injuries, fatalities, and illnesses [4]. The host of health problems involve hearing loss, cancers, musculoskeletal disorders (MSDs), and pesticide-caused and respiratory illnesses [5]. Among the non-fatal occupational illnesses appearing in farm workers, MSDs seem to be the most widespread [6, 7]. In particular, repetitive lifting and moving of heavy loads, prolonged trunk flexion (also called stooping), intensive hand work, and working in awkward postures of wrist and trunk are tasks associated with the main risk factors regarding the reported MSDs [6, 8, 9]. Remarkably, low back pain is recognized as the most prevalent musculoskeletal disorder that the agricultural workforce suffers from, in both developed anddeveloping countries [8; 10; 11; 12; 13; 14]. In fact, repetitive and sustained stooping is the primary risk factor for low back pain [8]. The risk factors associated with the MSDs during different agricultural tasks have been extensively investigated in the literature; for example, in the harvesting of fruit and tree nut crops, climbing ladders meet the burden of bearing heavy loads, repetitive cutting, and excessive reaching. These arduous tasks turn out to cause pain in the whole body, but mostly in the hands, wrists, shoulders, and low back [9]. Concerning the harvesting of fresh market vegetables, such as tomato and lettuce, prolonged and iterative stooping, lifting loads of great weight, as well as intensive and repetitive cutting, contribute to discomfort also in the hands, wrist, and low back [9]. The same risk exposures with the similar pain complaints have been observed in nurseries and greenhouses [6; 9]. Finally, in vineyard work, the high risk of back injury is mainly due to the iterative forces imposed to the upper extremities and trunk in combination with awkward stooping, twisting movements, and repetitive lifting of excessive loads [15]. Weeding, namely, the examination of each plant to check the weed growth and decide if a removal of it is necessary by tools (hoe or shovel) or hand, is also a common hazardous operation. Prolonged stooping, stresses on the one hand from the tool, and on the other hand from the plant and repetitive gripping are the principal risk factors [6]. Overall, pains have been reported due to weeding in the neck, arm, shoulder, and trunk [15]. In addition to weeding, pruning constitutes an ordinary agricultural operation. In this task, the worker utilizes different shears for the purpose of cutting some parts of the plant. The dominant hand is exposed to iterative gripping, while the non-dominant one usually holds the cuttings with moderate ulnar deviation and wrist flexion. Again, the landmark risk factors comprise extended stooping; awkward postures of both dominant and non-dominant wrists, as previously mentioned; and stresses from the shears [6]. Wrist, shoulder, and elbow pains have been observed to be associated with pruning [15]. Finally, repetition of lifting, carrying, and moving of heavy loads by using awkward postures is a common risk factor in a plethora of industries, including of course agriculture. Complaints for low back, wrist, and shoulder pains have been widely mentioned by workers [6].