Salāmat-i kār-i Īrān (May 2020)
Investigating the body postures and the prevalence of musculoskeletal discomfort in fruit pickers
Abstract
Background and AimS: Musculoskeletal discomfort is one of the most important causes of occupational disabilities in many work communities which cause high costs for the economies of countries. Studies signifies the importance of implementation of programs to control these discomforts. In this regard, the ranking of occupational and work-related diseases provided by the World Health Organization (WHO) has shown that musculoskeletal disorders had second place after work-related respiratory diseases in 2013. Agricultural workers are at high risk of musculoskeletal disorders due to the nature of their intense physical activities and high level of manual labor. Indeed, farmers experience a variety of physical pressures due to repetitive lifting and carrying heavy loads, working with inappropriate tools, working in undesirable conditions with awkward postures (bended and/or deviated trunk, abducted arms, working at height higher than shoulders, etc). They usually work with vibrating tools and are exposed with other hazards such as falling or slipping. Many observational ergonomic assessment tools are designed for evaluating the postural risk of different job tasks. Some examples include the Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), Quick Exposure Checklist (QEC), and so on. Agriculture is an occupation that depends highly on working methods and equipments. As a result, workers can adopt different postures as a function of their tasks and situations. It is assumed that their working postures would be more or less different from industrial workers. The majority of previous researchers applied typical existed methods to evaluate farmer’s working postures, since there was no specialized evaluation method. This lack of a proper agricultural evaluation method has recently been resolved by Kong et al. (2015), who introduced a methodology entitled “Agricultural Whole-Body Assessment” (AWBA) for this purpose. This approach covers a wide variety of body postures which are especially existed in agricultural tasks. Agricultural workers and their ergonomic conditions are rarely investigated in Iran. To our knowledge, no study has yet paid attention to the working posture of Iranian agricultures using AWBA. Considering the high number of workers in this section, and the lack of required information in order to decide appropriate interventions, the present study is conducted to assess the prevalence of musculoskeletal discomfort and the evaluation of working postures among fruit picker in Iran. Materials and Methods: A total of 135 fruit picker working in Damavand apple gardens voluntarily participated in this study. The study was approved by the ethics committee of Shahid Beheshti University of Medical Sciences and the written consent form was signed by each participant before starting. The inclusion and exclusion criteria for the study were having at least one year of working experience in the fruit picking job, and lack of any specific work-related musculoskeletal disorders. Also, individuals who experienced acute musculoskeletal injuries due to non-occupational reasons during the study, and those who declined to continue their participation for any reason were excluded from the study. In this study, only fruit pickers who picked fruit from short trees without needing to ladder were entered. A researcher-made questionnaire was used to identify the demographic and occupational characteristics of the employees. Accordingly, factors including age, sex, height, weight, and work experience were collected. The prevalence of musculoskeletal discomfort was recorded by a body map questionnaire during the study period. The body map questionnaire attempts to identify body regions involved with musculoskeletal disorders. The body map questionnaire classifies whole human body into nine anatomical areas. Workers were asked to mark each area in which they feel discomfort. AWBA was used to evaluate working postures and to determine the ergonomic risk level. This tool provides the risk levels for the upper (AULA) and the lower (ALLA) limbs, taking into account the different postures of the body during the work as well as the working duration in each posture. Finally, using a 4x4 matrix, the overall risk level of the whole body is determined. The final risk levels can range from 1 (low) to 4 (extremely high). Data was analyzed with SPSS software version 16, using t-test and Mann-Whitney test. Results: The prevalence of musculoskeletal discomfort among the studied fruit pickers was 31.9%, 22.2%, 20.7% and 14.8% in lower back, knees, legs/foots and shoulders respectively. In total, 88 out of 135 workers (65.2%) experienced musculoskeletal discomfort in at least one region of the body while 47 workers (34.8%) reported no discomfort. The age of participants ranged from 12 to 73 years (mean = 35.9 ± 15.7). The history of work ranged from 2 to 50 years with an average of 12.8 ± 11.4. Individual characteristics including age, height, weight, work experience and body mass index were not related with the presence of musculoskeletal discomfort among studied workers (P >0.05). According to the results obtained from the Agricultural Whole-Body Assessment method, the risk score of three was calculated for the upper limbs (AULA), lower limbs (ALLA) as well as whole body (AWBA); indicating high risk of musculoskeletal disorders in fruit pickers due to their excessive exposure to physical ergonomics hazards. Conclusion: Fruit pickers are at high risk of musculoskeletal disorders. Awkward working postures in manual fruit harvesting may be considered as the main cause for the incidence of MSDs in this working group. Although the lower limbs (foot, legs, knees) of fruit pickers seem more painful than other body parts, it is important to consider their whole body (including lower and upper limbs) in the case of designing any ergonomic improvements, since both lower and upper limbs are at high risk of MSDs in traditional apple harvesting. Therefore, appropriate yet prompt ergonomic interventions should be implemented. In this regard, moving to the mechanized agriculture seems to have the highest priority among all possible interventions. However, until it could be realized, other ergonomic improvements should be adopted. These include all changes resulting in reducing repetitive movements, modifying working postures (i.e. avoiding excessive bending, twisting, deviating, abducting arms, working over the shoulder height, reaching beyond the natural working zone envelope, etc), decreasing prolonged standing, and reducing exposure to the biomechanical risk factors such as force and prolonged working hours. It is also recommended to improve the traditional methods of fruit handling and carrying by designing ergonomic baskets dedicated for this purpose.
