Investigation of prevalence and risk factors of musculoskeletal disorders among tea harvesting farmers: A systematic review

Abstract

BACKGROUND:

Tea harvesting is a common agricultural occupation, usually conducted in mountainous regions with steep slopes and high altitudes. Despite the utilization of modern technology and mechanized equipment in agriculture, a substantial portion of tea harvesting continues to be traditional and physically strenuous. This dependence on manual labor can lead to a higher likelihood of musculoskeletal disorders among tea harvesting farmers.

OBJECTIVE:

The objective of this research was investigation of prevalence and risk factors of musculoskeletal disorders in tea harvesting farmers.

METHODS:

In this review study, we analyzed all published articles on the prevalence and factors influencing musculoskeletal disorders in tea harvesting farmers from March 10, 2010, to November 10, 2023 (last search date). We systematically searched for articles using keywords (risk factor, risk assessment, lower limb, upper limb, musculoskeletal disorders, tea harvesting, posture, manual handling, discomfort, ergonomics, prevalence, farmers) in PubMed, Google Scholar, SID, Web of Science, Scopus, Magiran, Iran Medex, Cochrane Library, and Embase. The quality of the articles was evaluated using the Mixed Methods Appraisal Tool (MMAT), 2018 version. Unrelated articles were excluded following PRISMA statement guidelines, and only articles directly related to the study were reviewed. GraySource and BASE databases were also utilized to identify Gray sources..

RESULTS:

Initially, 128 articles were found across different databases, and a total of 17 articles were selected for the final assessment. The primary areas of the body that workers are commonly exposed to musculoskeletal issues are the back, hands, wrists, shoulders, neck, and knees. The research identified four main categories of factors: personal, occupational, environmental, and psychosocial that contribute to musculoskeletal problems. Among these factors are women working in physically demanding environments, lifting heavy bags of harvested tea, time pressures during tea collection, repetitive hand motions from using harvesting tools, the height of the tea plants in the field, working in wet and slippery conditions, uneven ground surfaces, extended working hours, low pay, and lack of support from employers.

CONCLUSIONS:

Ergonomic interventions such as redesigning tea harvesting tools, enhancing tea plants and workspaces, teaching ergonomic principles of body posture and manual movement, and organizing work with job rotation and adequate rest are recommended to alleviate musculoskeletal disorder symptoms.

Keywords

Farmers tea harvesting agriculture personal occupational environmental psychosocial risk factors

1 Introduction and background

Musculoskeletal discomforts are a complex group of diseases with various contributing factors. Personal factors like age, gender, and obesity play a role, as well as occupational and psychosocial factors. Epidemiological studies have shown a link between body mass index and lower extremity musculoskeletal disorders (LE-MSDs)¹, with overweight or obese classification being a risk factor for knee osteoarthritis [1]. Occupational risk factors include improper posture, lifting heavy loads, repetitive movements, applied force, and vibration. Psycho-social factors, such as job satisfaction, coworker support, and perceived job stress, also impact the worker’s perceptions and can contribute to MSDs². Low job satisfaction and poor social support from coworkers are risk factors for hip, knee, and leg pain. Additionally, moderate to severe occupational stress is associated with knee pain [2].

Farming has always been a risky job. In the past, farmers used to work without advanced tools and facilities, which brought its own difficulties [3]. Due to the physical demands and manual labor involved in agricultural work, workers in this field are at a high risk of developing musculoskeletal disorders [4]. The frequency of these conditions among farmers is notable, with certain investigations suggesting that musculoskeletal conditions are the most prevalent non-lethal work-related harm in this field. The task of tea harvesting is especially vulnerable to a range of physical, chemical, biological, ergonomic, and psychological strains, as well as excessive work demands. These detrimental elements encompass skin ailments, sensitivities, the application of pesticides and weed killers, incorrect posture, high temperatures and humidity, laboring on uneven terrain, utilizing unsuitable traditional hand implements, and neglecting personal protective gear [5, 6]. Figure 1 depicts some images of tea farmers during the tea harvesting activity.

Fig. 1

Some common occupational situations in tea harvesting farmers.

Tea harvesting workers endure these conditions and labor during the summer season when the air temperature and humidity increase. According to the ILO, agricultural and construction workers are projected to lose 60 and 19 percent of work hours due to heat stress in 2030, respectively [7]. Many of the tools and equipment used by tea farmers are physically unsuitable, and they also have to carry heavy tea bags in a traditional manner. Access to sanitary facilities, work clothes, and suitable personal protective equipment is restricted for these workers [8]. There is often a mismatch between the amount and type of work and the body size, shape, and strength of the tea farmers. Women, especially pregnant women, experience additional stress due to their physiological characteristics, leading to abnormality and adverse effects on the fetus. Communication in tea fields is traditional, and social security does not cover workers, who are mostly family members, if the farmer has 10 hectares of agricultural land. Insurance for villagers and nomads is limited to retirement and disability coverage, excluding medical insurance [9]. Many of them are not familiar with health centers and related training, and no occupational health assessments are conducted for these individuals. Tea harvesting takes place in mountainous, sloping, and high altitude areas [4]. Even with mechanized tools in agriculture, tea harvesting still depends on traditional methods, demanding physical strength. This may result in more musculoskeletal issues among worker [10]. Studies carried out among tea farmers have uncovered different forms of musculoskeletal issues, such as knee discomfort, back pain, and upper and lower limb disorders, with differing occurrence rates [11, 12].

Despite the high number of people employed in this profession, and the presence of unfavorable working conditions and risk factors, there have been limited studies conducted to investigate the prevalence of musculoskeletal disorders related to the work of tea farmers worldwide. In Abdul Hadi’s study, which aimed to determine the prevalence and factors related to back pain among tea harvesting farmers in Malaysia, the results showed that 81.1% experienced back pain during work, and 64.2% experienced back pain in the last 12 months [25]. In a different study by Masri et al., the occurrence of musculoskeletal pain among tea harvesting farmers in the past year was documented by body regions, such as neck (34.6%), shoulder (24.8%), elbow (22.2%), wrist (38.5%), upper back (26.9%), lower back (35%), hip (24.4%), knee (32.9%), ankle (18.4%), and foot (24.4%) [13].

Despite the limited research on musculoskeletal issues in tea harvesting farmers, there has not been a comprehensive review on the prevalence and factors influencing musculoskeletal injuries in this group. Thus, this study aims to establish the frequency of musculoskeletal injuries, highlight the common body areas affected, and uncover the risk factors linked to these injuries in tea harvesting farmers.

2 Methods

2.1 Study design

According to the PRISMA guidelines, this study was based on a systematic review of published literature [15]. In this review, all Persian and English articles were analyzed to investigate the prevalence and factors influencing musculoskeletal disorders in tea harvesting farmers.

2.2 Search strategy and eligibility criteria

The study’s search strategy was developed in collaboration with two members of the research team. An electronic search was conducted using the titles of abstracts in various databases, such as PubMed, Google Scholar, SID, Web of Science, Scopus, Magiran, Iran Medex, Cochrane Library, and Embase. The search terms or keywords used included: risk factor, risk assessment, lower limb, upper limb, musculoskeletal disorders, tea making, posture, manual load carrying, discomfort, and ergonomics. GraySource and BASE databases were utilized to find gray sources. The words “AND” and “OR” were used to connect the search terms in all the databases. The following criteria were applied to screen the identified sources: Selection of original articles with full text in English and Persian.

Removal of review articles, editorials, letters to the editor, articles presented in conferences, and reports.

Time period from March 10, 2010, to November 10, 2023 (the last search date) due to the publication of the maximum number of articles in this time period.

Removal of articles not related to tea harvesting farmers.

Removal of articles that do not provide sufficient details about musculoskeletal disorders.

Insufficient volume of statistical samples.

Removal of articles that only focused on a limited number of body areas.

2.3 Data recovery

EndNote 22 software was utilized to arrange the articles detailing the studies found in this review. The search findings from the databases examined were merged in an EndNote page and redundant entries were deleted.

2.4 Study selection and data extraction

Two authors independently assessed all titles and abstracts of articles for eligibility. Full-text manuscripts of all relevant titles/abstracts were obtained, and the relevance of each study was assessed based on the inclusion/exclusion criteria by two reviewers independently. Studies that did not meet the criteria were excluded. Any discrepancies were resolved through consensus and re-examination of the articles.

The data extracted from the articles included: author’s name, article title, study method (instrument, study type, and number of samples), and type of risk factor (personal, occupational, environmental, and psycho-social). Two team members designed these features in a table. After selecting the studies, two authors independently extracted the output data using a standardized table. To avoid repetition, other researchers re-examined the selected articles.

2.5 Methodological quality assessment

Unrelated articles were excluded following PRISMA statement guidelines, and ultimately, only articles directly relevant to the study were reviewed. Various tools and checklists have been created for the critical evaluation of studies, intended to assess and rank studies for analytical assessment of study quality, aiding in identifying potential bias in their design, execution, and analysis. In this study, irrelevant articles were filtered out using the PRISMA checklist, and only articles closely related to the study were analyzed. PRISM is a guideline developed to enhance the reporting of structured reviews and meta-analyses. Therefore, authors of scientific articles refer to Prism guidelines to prepare and publish systematic reviews [15]. The presence of each item was checked, and the evaluation obtained by each reviewer was compared. Discrepancies were discussed for final evaluation, and a third reviewer was involved if necessary.

To evaluate the quality of the articles, the Mixed Methods Appraisal Tool (MMAT), 2018 version, was used. MMAT is a tool for evaluating the quality of studies with various quantitative, qualitative, and mixed methodologies. The validity and reliability of this tool have been confirmed by studies. The evaluation of the quality of studies using this tool is divided into two stages. First, all studies are evaluated regardless of methodology. Two questions are considered as screening questions for this purpose. Only the studies that meet the conditions based on these two questions are further reviewed. In the next step, the evaluated studies are reviewed based on the type of methodology and design [16]. In this study, all selected studies were descriptive-analytical and cross-sectional. Five questions related to this section were utilized. Studies that did not meet any criteria or only met one question were classified as low-quality studies. Studies meeting two or three questions were considered moderate quality, while those meeting all questions or four of them were deemed good quality studies.

3 Results

3.1 Search results

In total, 128 articles were reviewed, after removing duplicates and applying inclusion and exclusion criteria, 17 related articles were selected. Figure 2 also shows the flowchart of data processing. Table 1 shows some eligible studies that have examined the ergonomic risk factors associated with musculoskeletal disorders in tea harvesting farmers. The characteristics of the articles have been analyzed separately for each study based on the title and method of the study, the target organ and the type of risk factor (Personal, Occupational, Environmental and Psychosocial).

Fig. 2

The process of reviewing and selecting the studied articles Based on PRISMA principles.

Table 1

Articles of reviewed in the field of investigating the prevalence and factors affecting musculoskeletal disorders in tea harvesting farmers

Row	Author and year of publication	Article title	Method of study			Target organ	Risk factor
			Tools	Type of study	Sample size		Personal	Occupational	Environmental	Psychosocial
1	Langat (2015) [30]	Determining the prevalence and evaluating the occupational risk factors of back pain among tea growers and non-tea growers	Researcher made questionnaire	Filed study	454	Back	Age	Working time – Number of kg of tea leaves harvested – Number of kg of tea bags transported per day	Height of tea plant	No review
2	Abdul Hadi (2016) [25]	Prevalence and associated factors of back pain among tea plantation workers in Malaysia	Researcher made questionnaire	Filed study	128	Back	Ethnicity – Education level	Type of work – frequency (low or high) of bending forward – body twisting – side bending – duration (long) of standing – exposure to whole body vibration – carrying heavy loads – duration of work – poor posture – repetitive movements	slippery ground	Lack of support and help from colleagues and employers – need to work quickly – low job satisfaction
3	Gayatri Devi et al. (2018) [8]	Prevalence of work-related musculoskeletal disorders among women workers of a tea factory in India	Nordic questionnaire	Filed study	40	Neck – shoulders – back – hips – knees – wrists	No review	Lifting loads – lifting above shoulder level – lifting with one shoulder – pushing and pulling loads over 25 kg – insufficient rest	High density of tea plants	No review
4	Chandraskara et al. (2020) [9]	Prevalence of musculoskeletal pain and environmental health risks among tea growers in a province in Sri Lanka	Researcher made questionnaire	Filed study	378	Lower back area – knee – shoulder – hand and arm – ankle	age of starting work	Duration of work per day – work history	No review	Stress – support from the employer
5	Masri et al. (2017) [13]	Work-Related Musculoskeletal Disorders Among Tea Pluckers	Nordic questionnaire	Filed study	236	Wrist – neck – back – knee	No review	Manual handling of loads (lifting, lifting with one shoulder, lifting over the shoulder, pushing, pulling loads over 25 kg) – posture – prolonged bending – long hours of activity – long reach	Type of tea harvesting area (plains and mountains)	No review
6	Tasanawong et al. (2018) [47]	Prevalence and Factors Associated with Musculoskeletal Disorders among Thai Burley Farmers	Questionnaire of exposure to ergonomic factors – Nordic questionnaire	Filed study	167	back – knee – shoulder – neck	Gender height Weight	Inappropriate physical posture – repetitive work – working time	No review	Insufficient salary
7	Kayari and Dey (2022) [48]	Prevalence of work-related musculoskeletal symptoms among tea garden workers in Bangladesh: a cross-sectional study	Nordic developed questionnaire	Filed study	346	Shoulder – upper back – back – neck – knee – ankle	sex	Increased working hours – overtime – rest – excessive force – repetitive movements	Uneven ground surfaces (uphill and downhill)	Failure to provide adequate training on the correct way to do the job
8	Dianat et al. (2020) [49]	Work posture, working conditions and musculoskeletal outcomes in agricultural workers	Questionnaires and direct observations of posture (using the Rapid Upper Limb Assessment [RULA] method)	Cross sectional	377	low back pain – neck pain – upper back pain	Gender – Age – BMI	Years worked as an agricultural worker – Daily working hours – Manual material handling – Working in standing position	No review	Income level – Job satisfaction
9	Thetkathuek et al. (2022) [50]	A Cross-sectional Study of Musculoskeletal Symptoms and Risk Factors in Cambodian Farm Workers in Eastern Region, Thailand	Nordic Musculoskeletal Questionnaire, Rapid Upper Limb Assessment, and Hazard Zone Jobs Checklist techniques	Cross sectional	861	Shoulder – upper back and lower back	Sex – Marital status – Education	Type of work- Work experiences (years) – Work hours per day	No review	Overtime work – Break during work
10	Bhattacharyya and Chakrabarti, (2012) [51]	Ergonomic basket design to reduce cumulative trauma disorders in tea leaf plucking operation	OCRA and QEC methods – Rating of Perceived Exertion (RPE) – NMQ (Nordic Musculoskeletal Questionnaire) and the body map	Cross sectional	180	Head – Neck – Buttocks	Age – BMI	Weight of tea – The weight of the tea basket -The length of the basket handle	No review	–
11	Govindankutty and Priyadarshan (2018) [52]	A Study On Occupational Health Hazards And The Safety Measures Taken By The Tea Plantation Workers Of Kerala	A detailed questionnaire including: information on demography, personal habits, exposure history, health hazards of spraying pesticides, and ergonomic hazards and injuries	Filed study	225	–	Personal habits of the tea plantation workers – Age of the tea plantation Worker	Literacy rate of the tea plantation workers – Nature of work of the tea plantation workers – Working hours per week – Accident that occurred in the tea plantation regularly	No review	Level of Job Satisfaction of the tea plantation workers – job stress – quality of work life
12	Rahul Jain et al. (2018) [53]	Risk factors for musculoskeletal disorders in manual harvesting farmers of Rajasthan	Nordic Musculoskeletal Questionnaire and the Rapid Upper Limb Assessment (RULA)	Filed study	140	lower-back, fingers, shoulders and wrists/hands	Age – Gender – Body mass index – Schooling – Hand domination	Daily working in farms (h)	No review	Salary satisfaction –
13	Pramod Dihingiaa and Krishna Dewanganb (2012) [22]	Musculoskeletal symptoms among tea pluckers in India	Nordic questionnaire	Filed study	500	Shoulders – neck – upper back – wrists/hands – lower back	Gender – Age – Working habit – Experience	Duration of work for tea plucking per day, h – Duration of work other than tea plucking per – Average maximum load carried per day during tea plucking	No review	No review
14	Vasanth et al. (2015) [54]	Prevalence, pattern, and factors associated with work-related musculoskeletal disorders among pluckers in a tea plantation in Tamil Nadu, India	Four parts: sociodemographic detail, Standard Nordic Scale, numeric and facial pain rating tool, and a tool to assess factors associated with WRMDs	Cross-sectional study	195	Shoulder – lower back	Age – Education status	No review	No review	Source income
15	Javidi Gharacheh and Khojastehpour (2014) [14]	Ergonomic evaluation of tea growers in the north of the country during harvesting using the body simulation method	OWAS, REBA and RULA methods	Cross-sectional study	30	Trunk region neck – upper arm – lower arm – wrist	Gender	harvesting methods	No review	No review
16	Banibrata Das (2023) [42]	Work-related musculoskeletal disorders in agriculture: Ergonomics risk assessment and its prevention among Indian farmers	Standard Nordic questionnaire, ergonomic assessment tool (REBA), and ART tool	Cross-sectional study	–	Knees – shoulder – neck – ankle or foot – upper back region	No review	Postures – activities repetitive	No review	Working long hours – monotony at work –
17	Teeraphun Kaewdok et al. (2021) [55]	Agricultural Risk Factors Related Musculoskeletal Disorders among Older Farmers in Pathum Thani Province, Thailand	Three-part questionnaire generated data that included demographics, work conditions, and environment, and self-reported MSDs.	Cross-sectional study	481	Lower extremities – lower back – shoulders	Sex	Using agricultural tools/equipment – Prolonged static postures – Manual material handling	No review	No review

In recent years, there has been a limited number of articles published on the topic of tea harvest workers. Some of these articles have not specifically addressed the issues faced by tea harvest workers and have instead grouped them with other agricultural occupations. The predominant survey tool used to assess the prevalence of musculoskeletal disorders in these studies was the Nordic questionnaire. Other common ergonomic risk assessment methods included RULA, REBA, and OWAS. All studies were conducted cross-sectionally in the field, with no intervention studies conducted.

The research identified the back, hands and wrists, shoulders, neck, and knees as the body parts most at risk of musculoskeletal disorders in this line of work. Risk factors for musculoskeletal disorders were categorized into four groups. Individual risk factors included age, gender, and work experience. Occupational factors encompassed poor physical condition, manual handling of heavy loads, improper use of hand tools, and long work hours. Environmental factors involved uneven terrain in highland tea fields and slippery surfaces in tea gardens due to rain. Psychological and social factors included lack of employer support, low wages, and inadequate welfare provisions.

3.2 Evaluation of the quality of articles

The quality assessment of 17 included articles showed that most of the reviewed studies (12 articles) were of moderate quality. Studies by Langat (2015), Masri et al. (2017), Kayari and Dey (2022), Dianat et al. (2020) and Banibrata Das (2023) were considered high quality cases (Table 2). Also, three studies were determined to be of low quality.

Table 2
Evaluation of the quality of included studies based on the MMAT checklist

High quality Medium quality Low quality

Langat (2015) Abdul Hadi (2016) Javidi Gharacheh and Khojastehpour (2014)

Masri et al. (2017) Chandraskara et al. (2020) Gayatri Devi et al. (2018)

Kayari and Dey (2022) Tamal Kanti Kairi and Sanghamitra Dey (2022) Tasanawong et al. (2018)

Dianat et al. (2020) Bhattacharyya and Chakrabarti, (2012) –

Banibrata Das (2023) Govindankutty and Priyadarshan (2018) –

– Rahul Jain et al. (2018) –

– Vasanth et al. (2015) –

– Teeraphun Kaewdok et al. (2021) –

– Pramod Dihingiaa and Krishna Dewanganb (2012) –

High quality	Medium quality	Low quality
Langat (2015)	Abdul Hadi (2016)	Javidi Gharacheh and Khojastehpour (2014)
Masri et al. (2017)	Chandraskara et al. (2020)	Gayatri Devi et al. (2018)
Kayari and Dey (2022)	Tamal Kanti Kairi and Sanghamitra Dey (2022)	Tasanawong et al. (2018)
Dianat et al. (2020)	Bhattacharyya and Chakrabarti, (2012)	–
Banibrata Das (2023)	Govindankutty and Priyadarshan (2018)	–
–	Rahul Jain et al. (2018)	–
–	Vasanth et al. (2015)	–
–	Teeraphun Kaewdok et al. (2021)	–
–	Pramod Dihingiaa and Krishna Dewanganb (2012)	–

4 Discussion

The study aimed to investigate the prevalence and factors influencing musculoskeletal disorders in tea harvesting farmers through a systematic review. The analysis of articles revealed that musculoskeletal injuries are common among tea harvesting farmers, particularly in the upper and lower body regions.

This finding aligns with the findings of a systematic review of 24 studies by Osborne, indicating that the prevalence rate of MSDs of all types over a one-year period was 76.9% [17]. According to the study, pain in the back, hand and wrist, shoulder, neck, and knee is more commonly reported among farmers compared to other musculoskeletal areas, and these findings align with the results of the Razavi [18], Osborne [17], and Jaafari Roudbandi [19] studies. It appears that engaging in strenuous physical activities, manually lifting heavy loads, and a lack of understanding of ergonomic principles related to the human body contribute significantly to the high incidence of these disorders, as highlighted in a separate study [19]. There are numerous pieces of literature that explain MSDs is multifactorial [20, 21]. Symptoms can be affected by work methods, traits, job types, and personal and sociodemographic factors. Psychosocial factors may also contribute to MSDs development. The importance of age, work experience, breaks, and overtime in MSDs development should not be underestimated.

The study categorized the factors contributing to these issues into Personal, Occupational, Environmental, and Psychosocial factors.

4.1 Personal risk factors

Many studies have explored the link between Personal traits and musculoskeletal disorders. Pramod et al.’s research on tea farmers revealed that women have a higher likelihood of experiencing musculoskeletal symptoms compared to men. Women often work alongside men in this profession, and due to the physically demanding nature of the tasks involved, they are more susceptible to injuries. Women are frequently required to carry their babies on their backs while working, leading to strain on their backs while tea harvesting. This is likely because women are more exposed to physical and psychosocial risk factors and have weaker muscles and shorter stature than men. Women may face a higher relative musculoskeletal load when engaging in similar activities as men because most workplaces are planned based on male anthropometric data, and they may also juggle dual roles as a worker and homemaker.

Moreover, individuals with a higher body mass index (BMI) experienced more discomfort [22].Various studies have also indicated that gender, age, and BMI are closely linked to musculoskeletal disorders, with women being more affected by these disorders than men [23]. In addition, numerous studies have demonstrated the correlation between age and the development of musculoskeletal disorders. Functional abilities decline with age, leading to an increased risk of musculoskeletal disorders [24]. In this job, the elderly experience more discomfort than the young due to the heavy tasks, hindering them from carrying on with their job duties.

4.2 Occupational risk factors

During tea harvesting, tea farmers significantly experience MSD in their shoulders, wrists, back, neck, and knees. tea harvesting involves enduring heavy loads, repetitive movments, prolonged bending and excessive reaching, leading to pain throughout the body, primarily in the hands, wrists, shoulders, and back. Abdol Hadi demonstrated a notable correlation between occupational ergonomic stressors among tea farmars, including the nature of their work, bending forward, twisting the body, bending sideways, prolonged standing, and lifting heavy loads, and the occurrence of back pain within the past year [25]. Tea farmers often have awkward postures in various body parts (back, knees, wrists, shoulders) while working, leading to a higher incidence of musculoskeletal disorders. Working in an awkward posture is a primary reason for MSDs. awkward posture can result in rigidity and tension in skeletal and muscular regions, resulting in pain and unease across the body. The human body is not meant to remain stationary but to move within boundaries. Prolonged work in a static position elevates muscle strain and joint activity, leading to joint compression and impacting musculoskeletal symptoms [26, 27].

Studies have shown that during all phases of rice farming – from planting to harvesting, whether done traditionally or using modern methods – factors like prolonged bending, lifting heavy objects, and pushing or pulling heavy loads are identified as the primary causes of musculoskeletal disorders [26 –29]. Jumbo tea bags, weighing between 70 and 90 kg, exert significant pressure on tea growers, leading to discomfort and increased physical strain. Langat et al. research revealed a notable correlation between the amount of tea harvested and transported daily and the prevalence of lower back pain (LBP) among tea farmers. Carrying heavy tea bags poses a high risk for LBP, aligning with findings from previous studies [30]. Some studies have indicated that lifting heavy objects and performing repetitive movements can have a notable impact on the upper limbs, resulting in back pain and muscle damage in the hand and wrist [31, 32]. During tea harvesting, the head tilts forward and rotates to the left and right. This action creates a heavy load on the cervical spine discs in the neck region.

The role of tools and equipment is crucial in the discussion of musculoskeletal disorders, as they can enhance satisfaction and work ability when ergonomically designed. Tea farmers have identified factors such as the inability to adjust and the traditional design of hand tools, the lengthy bag attached to the tea harvesting tool, and the weight of the hand tool as contributors to musculoskeletal disorders. Various case studies have confirmed that the use of non-ergonomic tools and equipment is a significant factor in increasing musculoskeletal discomfort among tea farmers. These hand tools, crafted by local blacksmiths in a traditional manner with iron and wooden handles, require workers to use them for over 12 hours. A study by Caoduc et al. revealed a strong association between the use of non-ergonomic agricultural tools and the prevalence of discomfort in the upper limbs, particularly the hand/wrist, among elderly farmers [33]. In addition, they discovered that utilizing hand tools designed with ergonomic principles helps prevent fatigue and musculoskeletal discomfort.

4.3 Environmental risk factors

Limited research has been done on the influence of environmental factors on musculoskeletal disorders, and existing studies indicate that these factors can have a significant impact on the onset and worsening of MSDs. Magnavita et al. research findings support the connection between environmental factors and skeletal disorders [34]. Among the environmental factors, the height of the tea plant (short and tall) and the limited access to the entire space of the tea plant (the width of some plants in mountainous areas) can be mentioned. In the foothills, the height of the bush varies due to uneven ground, leading to workers having to bend their backs more with shorter bushes. Additionally, uneven accessibility of some bushes requires workers to bend and twist during tea harvesting. Studies have shown a significant link between musculoskeletal disorders and decreased productivity, which can be attributed to environmental stressors impacting the prevalence of such disorders in workers. Tea farmers have cited uneven ground surfaces (uphill and downhill) and slippery terrain in rainy weather as factors affecting their musculoskeletal health. Cultivation of tea bushes in foothills and slopes, with fewer mechanized structures, poses challenges for workers, especially in rainy conditions. Slippery ground surfaces during rain necessitate workers to harvest tea and transport jumbo bags from the garden to the warehouse under difficult conditions. The tea bag absorbs rainwater, causing an increase in its mass. Reducing the mass of the bag can be achieved by altering its design. By redesigning the tea bag, it prevents the need to carry heavy tea for an extended period, thereby reducing the compressive force on the cervical spine disc in the neck area.

These challenges are specific to tea harvesting farmers. Research has indicated that ground slope is a factor associated with musculoskeletal disorders in workers across all body parts. Working on inclined surfaces, such as lifting and carrying jumbo tea bags, can lead to occupational injuries due to concerns about overall body stability and the risk of slips altering posture and movement profiles [35, 36]. In the studies by Askaripoor et al., Widanarko et al., and Haghi et al., the influence of environmental factors and the nature of work on the occurrence of MSDs has also been discussed [37 –39].

4.4 Psychosocial risk factors

A review of the available articles shows that musculoskeletal disorders have a complex and multifactorial etiology that includes psychosocial factors [40, 41]. As a result, targeted interventions that minimize psychosocial stressors can have potential gains in reducing the prevalence of musculoskeletal disorders.

Salary has been a factor investigated in various studies. It has a direct impact on motivation and work performance. When tea farmers receive their salaries promptly and in accordance with their work, they feel more motivated and energetic, leading to reduced fatigue. Conversely, delays in payment can result in dissatisfaction and stress, as per Herzberg’s two-factor model. Salaries and benefits are considered “hygiene” factors, and their inadequacy can lead to negative physical and mental outcomes [42]. A study by BaniBrata revealed that psychosocial factors like inadequate income and work monotony are linked to the occurrence of LBP [43]. Also, in comparison to industrial jobs, tea farmers are not covered by social security insurance, and no occupational medical examinations are conducted for them by the employer. In case of suffering from various diseases and musculoskeletal disorders, they have to pay for their treatment.

One of the most significant predictors of musculoskeletal disorders is the quality of support from employers and colleagues. According to the study by Bani Brata (2023), which examined ergonomic and psychological risk factors for back pain among rice farmers in India, supportive discussions from the employer and colleagues when cooperation is needed, followed by work pressure as the main psychological factors. This finding was consistent with the results of the present study [44]. Colleagues’ support was one of the key factors influencing musculoskeletal disorders in tea farmers. When colleagues offer support, particularly during times of illness, individuals in a productive team that carries out tasks fairly and transparently experience fewer physical injuries and less fatigue. Consequently, the team’s working capacity and performance improve, leading to a decrease in musculoskeletal disorders [45]. The findings of a Korean study revealed that individuals experiencing high job stress and a lack of support from their superiors and peers are more likely to experience pain in their upper limbs (arms, elbows, wrists, and hands) and lower limbs (knees and feet), regardless of gender. This increase in pain is significantly higher compared to those with low job stress and strong support. [46]. The significance of social support in work settings, along with effective communication among coworkers and employers, as well as collaborative teamwork, must be acknowledged, and these employees should receive adequate training. It is essential to implement efficient and comprehensive interventions at various levels, such as individual and organizational, to enhance the psychosocial work environment and mitigate musculoskeletal disorders.

4.5 Limitations and strengths

The strength of the current study lies in the selection of articles regardless of the time period, allowing for a comprehensive review of research in this field, despite the limited number of articles. However, the study does have limitations. The primary limitation is that the results, particularly concerning the prevalence of WMSD, are based on a restricted number of reference sources. One major limitation of this study is the lack of access to the original articles of some studies, leading to the removal of certain articles. The articles included in this study were the only ones that met the selection criteria. It is recommended that more studies be conducted worldwide on the prevalence of musculoskeletal disorders in tea harvesting jobs and the factors influencing them. Since tea harvesting is deemed an informal occupation and informal workers lack legal occupational health and safety programs, this study could enhance awareness and facilitate communication among government agencies to formulate suitable prevention strategies.

5 Conclusions

Tea is primarily grown in developing and underdeveloped nations. Consequently, the occupational issues faced by tea farmers have long been overlooked. While musculoskeletal problems are now being investigated in various occupational environments worldwide, the attention given to them remains insufficient.

The outcomes of our systematic review of the literature reveal that exploring the prevalence of musculoskeletal disorders and the factors influencing them in tea harvesting workers is an area that has not been thoroughly investigated. Furthermore, the existing data on the prevalence of WMSDs³ impacting these laborers are extremely scarce. Tea harvesting farmers are significantly vulnerable to work-related musculoskeletal disorders. The key body parts at risk include the back, neck, wrists, and shoulders. Given the diverse nature of tasks in tea harvesting compared to personal tasks, factors influencing musculoskeletal disorders may include Personal factors (age, work experience, and a higher women presence in this job due to the physical activity demand), Occupational factors (involvement of joints in the upper and lower limbs, improper body posture, manual handling, use of traditional hand tools, exertion on the hand, lack of personal protective equipment provided by the employer), Environmental factors (humidity and temperature in the work environment), workspace (varied height of tea plants, restricted access to the entire plant, uneven ground surface during activity – uphill and downhill, and imbalance of the tea farmers), and Psychosocial factors (lack of support from colleagues and employers, and inadequate wages).

To prevent musculoskeletal disorders in tea harvesting workers, a comprehensive approach involving control measures (Personal, Occupational, Environmental, and Psychosocial factors) is essential. Interventions may include ergonomic redesign of work tools, enhancement of workspaces and tea plants, education on ergonomics principles for body posture and manual load handling, provision of personal protective equipment, and implementation of medical check-ups for workers. Workers also should lessen excessive force and repetitive actions and decrease static unsupported postures. they should take brief breaks like stretching, sitting, or changing position, if feasible, to prevent prolonged awkward positions and repetitive movements. Group work is more effective than individual work during the harvesting season as it decreases the occurrence of MSDs. To further minimize MSDs, tea farmers should be equipped with suitable tools to alleviate muscle strain.

Ethical approval

This article is extracted from the Ph.D. thesis in Ergonomics with Project no: 62038-99-3-1401 and Ethics code IR.TUMS.SPH.REC.1401.138 at Tehran University of Medical Sciences.

Informed consent

All participants provided informed consent prior to enrollment. No identifying information is presented in this work.

Conflict of interest

The authors declare that there are no conflicts of interest.

Footnotes

Acknowledgments

Not applicable.

Funding

This study was funded by Tehran University of Medical Sciences.

Notes

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