The prevalence of musculoskeletal diseases among casual dock workers

This study identified the prevalence of work-related musculoskeletal disorders among casual dockworkers. This is a retrospective and quantitative study, the data sources of which included the medical files of dockworkers from 2000 to 2009. Data were collected in a medical service for dockworkers using a previously developed form; descriptive quantitative analysis was performed. Ethical aspects were complied with. A total of 15.8% of the diagnoses identified among male workers referred to musculoskeletal disorders. Individuals older than 52 years of age and with more than 21 years working in the field predominated. The most frequent musculoskeletal diseases included low back pain (38.8%), tendinitis (19.7%), and neck pain (12.5%). These diseases can be prevented through health interventions, confirming the importance of developing clinical support in nursing in order to improve the quality of life of dockworkers.


Introduction
The organizational and structural elements that compose the context of labor in society can either benefit human life or harm the health of workers leading to the onset of significantly frequent pathologies such as Repetitive Strain Injury (RSI), the recently denominated Work-Related Musculoskeletal Diseases (WRMD) (1) , Cumulative Trauma Disorders (CTD), and Musculoskeletal diseases.This group of diseases is characterized by the occurrence of symptoms such as pain, numbness, feeling of heaviness and fatigue, which generally occurs in an insidious manner, especially in the upper limbs, though it can also affect the lower limbs (2) .Diseases develop due to excessive overload on muscles exposed to repetitive movements and localized strain, as well as in the case of work under whole-body vibration Almeida MCV, Cezar-Vaz MR, Soares KFS, Silva MRS. and when it is necessary to keep the arms above the shoulders region (2) .These conditions are usually caused by repetitive movements that exceed the resilience of the components of the locomotor system, such as bones, tendons, ligaments, and muscles.These are often associated with inappropriate work conditions and psychosocial factors.
In general, the occurrence of this group of diseases is associated with operational and organizational changes, a consequence of the implementation of new production technologies that lead to changes in the work structure and includes in the process new devices that affect the workers' quality of life and productive capacity and results, among other things, in absenteeism (3) .
Among the various productive areas of important economic representation in Brazil and in the world is the work performed in seaports, which through shipping, transportation of passengers or transportation and storage of goods, is a strategy for economic growth in cities where these ports are located and for the country in general (4) .
Most of the port activities that take place in companies operating in seaports are performed by casual dockworkers, so-called because, even though they are permanent workers, their work has a casual nature and is not ruled by a work contract, and is necessarily mediated by Workforce Management Agencies (5) .These workers develop six types of activities: wharfage, stevedoring, cargo checking, cargo repairing, surveillance of vessels, and block workers who's work routines include a heterogeneous occupational exposure, intensified by the principle of multifunctionality (5) .According to this principle, workers from different professions can perform distinct activities and tasks requiring the same qualifications, regardless of their profession.
The routine activities concerning port work expose individuals to situations that are harmful to health and conducive to diseases, such as inappropriate places where harmful cargo and material, like toxic and radioactive material, is handled, stored and transported; exposure to noise; vibrations of machines; inclement weather; contact with chemical substances; and inadequate work tools, among others, which determine these workers' health-disease continuums (2,6) .
Ergonomic and psychosocial exposure also stands out in the context of the work performed in seaports.
Inappropriate posture, intense work performed in shifts and involving repetitive tasks and movements, performed under psychological pressure, demanding the rapid acquisition of qualifications, training, and adaptation can be determinant in the onset of musculoskeletal disease.
The incidence of these diseases among casual dockworkers has been addressed in other studies (7)(8) , which emphasize the weight of loads to be handled and unloaded from inside holds and decks of vessels as potential causes for this groups of diseases.The group of musculoskeletal disorders was the most frequently reported by these workers (8) .
Therefore, there is a need for studies addressing this subject, especially in the context of work in seaports.

Delimiting the profile of morbidity among casual dockworkers can support nursing interventions in an
important field of health practice, aiming to prevent such conditions.Additionally, scientific production within the field of nursing concerning this subject in other contexts of labor is incipient; it often addresses nursing workers affected by these pathologies (1,3,(9)(10)(11) .Investigating other labor contexts is important in order to deepen knowledge in the field of Public Health Nursing.
Hence, this study's objective was to identify the prevalence of work-related musculoskeletal diseases among casual dockworkers.A form was developed based on recommendations provided by the Brazilian Ministry of Health, other instruments used in occupational health, and information contained in the medical files themselves-obtained through previous contact with the data source-to collect data (2,6) .

Results
A total of 953 files from the Port Work Medicine Outpatient Clinic were consulted; two (0.2%) files did not report the activity performed by the worker.Of the 951 consulted files, 152 were selected.These involve workers affected by musculoskeletal diseases: 73 (48%) were wharf workers, 57 (37.5%) longshoremen, 10 (6.6%) guarded vessels, nine (5.9%) were cargo checkers, two (1.3%) block workers, and one (0.7%) was a cargo repairman.
A total of 170 diagnoses were identified, indicating that 15 workers presented more than one pathological disease.The most frequent conditions were lower back pain with 59 (38.8%) cases, tendinitis accounted for 30 (19.7%) cases, and neck pain affected 19 (12.5%) workers.The three pathologies together accounted for more than half of the identified cases (71%).
Wharf work was the activity with the highest number of cases (N=84), followed by longshoremen (N=61), and cargo checkers (N=11), while block workers and cargo repairmen were those with the lowest number of diagnoses and records in the medical files (Table 1).In addition to the conditions already mentioned, other conditions were also observed, though with a lower frequency, such as arthroses, enthesopathy (such as epicondylitis), bursitis, synovitis, tenosynovitis, and a single case of trigger finger, which totaled 39 cases (25.8%).There were also occurrences of unknown work-related pathologies, totaling 18 cases (11.8%).

Discussion
The results highlight that musculoskeletal diseases affect port workers and these conditions should be the focus of interventions aiming to improve the quality of life of casual port workers.The results revealing that workers are affected by musculoskeletal diseases corroborate the reports of workers addressed in a previous study (8) .
The labor activities performed in a seaport require the manual handling of heavy loads, which in turn demand the physical strain of several muscle groups.Additionally, equipment such as vehicles, tractors, and mechanical shovels are frequently used, which exposes workers to whole-body vibration for virtually the entire work period.
Such conditions, coupled with the fact that tasks are performed while in a sitting position, arms maintained above shoulder-level, and a lack of regular exercise, contribute to the development of RSI/WRMD (1)(2) .
This study shows that in this context wharf workers, longshoremen, and vessel guards are those most affected by pathologies of this organic group (8) , confirming previous health information.Among the diseases identified, lower back pain was the most frequent and affected wharf workers and longshoremen, the activities of whom are the most representative in the sample.
The literature suggests that worker age is an important factor in the development of chronic lower back pain (2) , however, association among these variables was not significant in this study.Such a result may suggest there are other reasons for the development of these conditions, such as those related to working conditions and characteristics.In wharf work, these characteristics include transporting goods on the docks with the use of machines such as forklifts, tractors, automotive vehicles, belonging to the port service itself or to the ships (5) .
It is worth noting that the role of whole-body vibrations in lower back pain is intensified according to the magnitude of vibrations in work machines, depending on the type and time of exposure, human discomfort, and the potential onset of musculoskeletal diseases (12) .
A similar situation occurs with longshoremen.This arising from this exposure (2) .
Recent studies report of the existence of techniques able to ease the painful symptoms of lower back pain without the use of medication, such as regular ergonomic exercises in order to broaden the amplitude of joint movements and improve muscle results, in addition to physical therapy techniques such as Muscle Energy and Dynamic Muscular Reeducation (13)(14) .
In addition to these techniques, a nursing examination to assess the amplitude of the movement of body segments (15) is argued to be an efficient measure to detect musculoskeletal disorders that may lead to an inability to work.The implementation of these actions may delay the conditions' onset and also lead to the early identification of painful sites so that preventive measures are taken.
Lower back pain also leads to postural instability (13) , which may cause irreversible damage to workers who perform their activities at a height and are at risk of falling into the sea, such as when lashing * or unlashing cargo.Both activities are often performed on top of loads and equipment (i.e.containers, cellulose).Therefore, the work of individuals affected by these conditions may increase the risk of occupational accidents and the onset of work-related pathologies.
Another condition that stood out was tendinitis, a type of disease classified among shoulder lesions, which causes intense pain and limits movement in different segments of the affected limbs, changing according to the position in which one applies physical exertion (2) .
Many conditions related to tendinitis tend to affect the shoulder region, which is formed by the supraspinatus, infraspinatus, subcapularis, and deltoid muscles and their respective tendons, whose function is to stabilize the movement of the shoulders (2) .These factors are once again observed among wharf workers and longshoremen, who present the following diagnoses: tendinitis in the shoulder, elbow, forearm, wrist, and Achilles tendon.These are possibly caused by physical strain when manually moving loads for a prolonged period of time and in places that impede workers from properly positioning themselves.We note that tendinitis among dockworkers occurs in other sites besides those described in the literature (2) , such as the case of vessel guards, who's knees and ankles are the sites affected.
Hence, there is the involvement of workers who virtually work the entire shift in the vertical position checking the boarding and disembarking of people, as well as the movement of goods on gangways, ramps, decks, platforms, in holds and other areas of the vessel (5) .This study's results corroborate those of an investigation (17) that assessed workers from different professions, such as seamstresses and hairdressers, * Lashing cargo is intended to secure or bind the cargo in the vessels' holds or decks to avoid damage due to the sea's movements (16) .
This quantitative, descriptive and retrospective study was conducted in a seaport in the South of Brazil.Data sources included medical files from the Port Work Medicine Outpatient Clinic belonging to the Work Management Agency of Casual Port Work in this seaport.
comprised four sessions: characterization of the subjects, clinical data and medical diagnoses, health actions implemented by the professionals, and actions focused on evaluating the workers' health conditions when returning to work.The following variables were used: age, work experience, lifestyle, profession, race, lower back pain, lumbar sciatic pain, pain in the upper back, neck pain, arthroses, joint pain, arthritis, tendinitis, epicondylitis, bursitis, synovitis, tenosynovitis, and trigger finger.The records included all the diagnosed musculoskeletal diseases.Workers may present more than one related disease within the period of data collection, from 2000 to 2009.The data were double entered in the EPINFO 6.04 program, ensuring a clean and organized database.Then, the data were imported into the Statistical Package for the Social Sciences (SPSS), version 13.0, for descriptive statistical analysis, which included the computation of proportions and Person's Chi-square test.The level of significance was fixed at α=0.05.The study project entitled "Health, Risks, and Occupational Diseases -An integrated study in different workplaces", of which this study is part, was submitted to and approved by the Ethics Research Committee at the FURG, protocol 109/2010.Authorization was also asked from the Workforce Management Agency in Rio Grande, Brazil.Additionally, the researchers involved in the study ensured confidentiality of collected data.
is the second most affected class of workers, whose work characteristics are similar to those of wharf work.The difference is that these are performed inside vessels, such as in the decks and holds of ships.An additional factor in this context refers is that not all casual dockworkers performing both activities have the technical habilitation to operate the machines, which can impede rotation among workers in the work with the machines, not complying with the need to reduce the time of exposure to vibration for individual workers, one of the most efficient measures to alleviate the occurrence of lower back pain and occupational diseases

Table 2 -
Distribution of frequencies concerning the diagnoses of work-related musculoskeletal diseases according to sites.Rio Grande, RS, Brazil, 2010