Work-Related Musculoskeletal Disorders in Food Packing Workers: A Review of Prevalence and Workplace Factors

Introduction

Musculoskeletal diseases (MSDs) are significant contributors to work-related disabilities, lost-time illnesses, injuries, and impairments in both developed and industrially developing countries.¹ "Musculoskeletal disorders" refer to a broad spectrum of inflammatory and degenerative ailments affecting the muscles, tendons, ligaments, joints, peripheral nerves, and supporting blood vessels.²

Work-related musculoskeletal disorders (WRMSDs) are common occupational injuries resulting from unfavourable body exposure during various phases of production, loading, and transportation, which can lead to permanent physical effects and spinal cord injuries. WRMSDs affect muscles, tendons, joints, nerves, and soft tissues, and are characterized by accumulation over time, physical and mechanical stress, and discomfort.³

Workplace risk factors include physical, psychological, and psychophysical aspects, with individual factors such as age, gender, and body mass index (BMI) also playing a role.⁴ Physical risk factors include high forces, repetition, overhead work, prolonged static postures, local contact forces, and vibration.^1,4

WRMSDs are among the most common types of occupational injuries in both industrialized and developing countries, with developed countries showing the highest occurrence.³ These disorders contribute significantly to workers' compensation costs, accounting for at least half of all such expenses in many industrialized nations.⁴ The increasing trend of mechanization in developed countries has reduced the danger of musculoskeletal problems, but in industrially developing countries, poor working conditions and the lack of effective injury prevention programs contribute to the high rate of MSDs.⁵

WRMSDs are responsible for approximately 40% of all work-related costs globally. However, musculoske-letal disorders account for 7% of all diseases in society, 14% of doctor referrals, and 19% of hospitalizations.³ They are prevalent in many countries and have serious social and financial impacts, as well as implications for quality of life and work efficiency.^3,5 MSDs were ranked second after occupational respiratory disease by the National Institute of Occupational Safety and Health (NIOSH) based on disease prevalence, severity, and potential prevention.³

MSDs can develop three to four times more frequently in certain industries and occupations compared to the general population. High-risk industries include nursing facilities, air transportation, mining, food processing, leather tanning, and both heavy and light manufacturing (vehicles, furniture, appliances, electrical and electronic products, textiles, apparel, and shoes).²

Packaging is considered a significant and essential stage in both modern and traditional production processes, with most packing processes in workshops done manually.³ Physical activities such as lifting and shifting weights, repetitive movements, and unfavourable body positions are typical in packing workshops.^3,6-8 In this context, a significant rate of WRMSD occurrence can be anticipated.¹ Most food industries report a monthly sick leave rate of more than two working days for more than five employees, suggesting widespread musculo-skeletal disorders in many body regions among packing workers.^5,3,5,9 Preventing WRMSDs is still in its early stages, and there has been limited research on musculoskeletal disorders among packing workers.

Materials and Methods

Search Strategy

A systematic literature search was conducted using Google Scholar and PubMed, two widely used academic search engines. Google Scholar was chosen for its broad interdisciplinary coverage, while PubMed was selected for its specialized focus on biomedical and occupational health research. The search aimed to identify relevant studies on Work-Related Musculoskeletal Disorders (WRMSDs) among food packing workers, focusing on prevalence, ergonomic risk factors, and assessment methods.

To maximize the relevance of the retrieved studies, a combination of Medical Subject Headings (MeSH) terms and free-text keywords was used. The primary search terms included, “Work-Related Musculoskeletal Disorders,” “WRMSDs,” “Food Packing Workers,” “Occupational Health,” and “Ergonomics.” Additional synonyms and variations, such as “Industrial musculoskeletal disorders,” “Repetitive strain injuries,” and “Ergonomic risk factors in packaging,” were also incorporated. Boolean operators were applied to refine the search: “AND” was used to combine key concepts (e.g., "WRMSDs" AND "food packing workers"), “OR” was used to include synonyms (e.g., "ergonomic risk factors" OR "repetitive strain injuries"), and “NOT” was used to exclude irrelevant topics (e.g., "food packing workers" NOT "agriculture").

Study Selection Process

The study selection process involved multiple steps. First, titles and abstracts of all retrieved articles were screened for relevance based on the inclusion criteria. Next, duplicate records from different databases were removed. After the initial screening, full-text reviews were conducted to ensure that the selected studies met all eligibility criteria. Following this rigorous process, four studies were finalized for inclusion in the review (Figure 1).

Inclusion Criteria

Studies were selected based on predefined inclusion and exclusion criteria. The inclusion criteria for study selection required articles published between January 1, 2008, and August 1, 2023, written in English, and focusing on cross-sectional studies that assessed the prevalence, ergonomic risk factors, and assessment methods of work-related musculoskeletal disorders (WRMSDs) among packing workers. Studies were excluded if they were published before 2007, were interventional studies assessing treatments rather than prevalence, focused on non-packing workers (e.g. agricultural or office workers), or were published in languages other than English.

Results

After the final evaluation, four studies conducted between 2008 and 2023 with a total sample size of 483 workers were selected. The research method in these studies was cross-sectional, and disorders were related to different body parts. The Nordic Musculoskeletal Questionnaire was used as a tool in all the articles to determine the prevalence of musculoskeletal disorders. Rapid upper limb assessment was used in one study to evaluate exposure to risk factors associated with work-related upper limb disorders, with results analyzed using the chi-square test.

In terms of location, 32.9% of the studies were conducted in Iran, 12.42% in Maharashtra, and 54.65% in Kermanshah. The prevalence of WRMSDs was reported involving different body parts among various packing workers. Among pharmaceutical packing workers, the prevalence of upper back pain was higher (54.8%), while thigh pain was lower (26.2%). A study on workers in engineering industries showed that the neck (20.2%), shoulder (14.9%), elbow (14.4%), and knee (14.4%) were the most involved areas. Among the packing workers from various industries in Kermanshah city, back pain (24.6%) and neck pain (7.6%) were the most common WRMSDs. In workers manufacturing hygienic products, packing workers reported a higher prevalence of musculoskeletal symptoms (57.4%), compared to filling (53.7%) and manufacturing workers (46.3%).

Discussion

Prevalence and Risk Factors

The reviewed studies indicate a significant prevalence of Work-Related Musculoskeletal Disorders (WRMSDs) among food packing workers, with varying severity and affected body regions. The high incidence of WRMSDs can be attributed to several ergonomic and occupational factors, including repetitive motions, prolonged static postures, and high-force exertion, which are common in packaging activities. The findings align with previous research which suggests that packaging work often involves prolonged awkward postures and continuous upper limb activity, increasing the risk of musculoskeletal strain.^{1,3, 9,10}

The study by Pourmahabadian et al., on pharmaceutical packing workers found the highest prevalence of upper back pain (54.8%) and the lowest prevalence of thigh pain (26.2%). This suggests that prolonged static postures and repetitive upper limb movements contribute significantly to upper back strain, whereas lower limb engagement is comparatively lower in packing tasks. This aligns with ergonomic studies highlighting that repetitive overhead work and constrained postures primarily affect the upper back and shoulders, leading to higher prevalence rates in these regions.¹¹

Similarly, the study on engineering industry workers reported neck pain (20.2%) as the most frequent complaint, followed by shoulder (14.9%), elbow (14.4%), and knee (14.4%) pain. These findings suggest that frequent head flexion, reaching, and repetitive gripping actions significantly contribute to neck and upper limb discomfort. Prior research has shown that workstations with improper height adjustment and inadequate support for upper extremities increase strain on the cervical and shoulder muscles, leading to increased risk of WRMSDs.³

In the food-processing industries, back pain (24.6%) and neck pain (7.6%) were the most reported symptoms. The relatively lower prevalence of neck pain compared to other studies could be due to variations in worksta-tion design and task distribution. Workers in these indu-stries may experience more generalized strain rather than specific localized pain, potentially influenced by ergonomic factors such as workstation height, material handling techniques, and shift duration.² Additionally, workers manufacturing hygienic products reported higher WRMSDs in packing stations (57.4%), compared to filling (53.7%) and manufacturing (46.3%) roles. Packing workers are often required to perform repetitive manual tasks such as sealing, labelling, and arranging products, which contribute to upper limb strain. Studies have highlighted that workers engaged in rapid, repetitive activities without sufficient recovery time are more susceptible to muscle fatigue and chronic musculoskeletal pain.¹¹ The increased prevalence of WRMSDs in packing stations compared to filling and manufacturing suggests that continuous manual handling tasks, rather than static postures alone, are a key risk factor.

Explanation of WRMSDs in Packaging Workers

The observed prevalence of WRMSDs among food packing workers can be explained by several biomechanical and physiological factors. Repetitive tasks lead to cumulative trauma on muscles, tendons, and ligaments, causing microtears and inflammation over time. Prolonged standing and static postures contri-bute to reduced blood flow to muscle groups, leading to fatigue and discomfort. Additionally, excessive force exertion, such as lifting heavy boxes or pushing conveyor belts, increases strain on the musculoskeletal system, particularly in the lower back and shoulders.^4,5,11

Awkward postures, such as forward bending and wrist flexion during packaging, can lead to localized muscle fatigue and nerve compression, increasing the risk of conditions such as carpal tunnel syndrome and cervical strain.^4,8,10,12 Ergonomic deficiencies in workstation design, including improper desk height, lack of adjustable seating, and inadequate lumbar support, further exacerbate WRMSDs.^6,7,13 These findings highlight the need for improved ergonomic interventions in the packaging industry.

Implications for Prevention and Workplace Interventions

Given the significant burden of WRMSDs among food packing workers, targeted ergonomic interventions are necessary to mitigate risk. Implementing proper workstation design, such as height-adjustable tables and ergonomic chairs, can reduce awkward postures and provide necessary lumbar support. Employers should also introduce periodic rest breaks, job rotation strategies, and stretching programs to minimize muscle fatigue and improve worker endurance.

Worker education on proper lifting techniques, posture correction, and early symptom recognition can help prevent the progression of musculoskeletal disorders. Additionally, integrating assistive devices such as automated lifting tools, conveyor systems, and ergonomic packaging stations can significantly reduce manual strain. These interventions have been shown to lower WRMSD prevalence in other industrial settings and should be prioritized in food packaging environments.⁹

Future research should focus on developing industry-specific ergonomic guidelines and evaluating the long-term effectiveness of intervention programs. The integration of wearable sensors and motion tracking technology may also provide valuable insights into real-time ergonomic risks and facilitate personalized interventions for workers.

Conclusion

The prevalence of WRMSDs among food packing workers highlights the urgent need for ergonomic inter-ventions and occupational health strategies. Repetitive movements, prolonged static postures, and high-force exertion contribute significantly to musculoskeletal strain, with upper back, neck, and shoulder pain being the most commonly reported symptoms. Workplace modifications, ergonomic training, and assistive devices can play a crucial role in reducing WRMSD risks and improving worker well-being. Future research should continue to explore innovative solutions for minimizing musculoskeletal disorders in the packaging industry.

Conflict of Interest

Nil