|Year : 2020 | Volume
| Issue : 2 | Page : 287-291
Comparative study of work-related musculoskeletal disorders among mechanized and manual stone miners
Shalvin Nimje1, Sarang Dhatrak2, Subroto Nandi3
1 Research Scientist, National Institute of Miners' Health, JNARDDC Campus, Wadi, India
2 Department of Orthopaedics, National Institute of Miners' Health, Nagpur, Maharashtra, India
3 Department of Orthopaedics, National Institute for Research in Environmental Health, ICMR, Bhopal, Madhya Pradesh, India
|Date of Submission||11-Dec-2019|
|Date of Decision||15-Jan-2020|
|Date of Acceptance||20-Feb-2020|
|Date of Web Publication||21-Dec-2020|
Dr. Sarang Dhatrak
National Institute of Miners' Health, JNARDDC Campus, Wadi, Nagpur - 440 023, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: Workers in the mining industry are prone to multiple health problems including musculoskeletal disorder. Very few studies are available assessing the occurrence of work-related musculoskeletal disorder (WMSD) among manual and mechanized mine workers due to unergonomic working conditions. Aims: The aim of this study is to establish and compare the prevalence of WMSD due to unergonomic working conditions among the manual and mechanized miners with age and work exposure and also to identify the most commonly affected body region. Materials and Methods: A questionnaire-based survey of about 889 manual and mechanized miners was conducted in different states of India. Results: It was also observed that vibration exposure was relatively higher among manual miners (62%) as compared to mechanized workers (45%) and also manual lifting of heavy loads is common practice in manual miners with 73% miners engaged in it as compared to only 23% mechanized miners. WMSDs were significantly higher in manual miners (61%) as compared to mechanized miners (36%). Odds ratio of WMSDs in relation to the age group of 18–40, 41–50, and 51–60 years was 2.56, 2.25, and 2.76, respectively, and in relation to work exposure of 0–10, 11–20, and >20 years was 3.38, 2.17, and 2.59, respectively, indicating that manual workers are much more prone for WMSDs. Conclusion: Our study showed that due to unergonomic working conditions, manual mine workers are more prone for WMSDs as compare to mechanized mine workers and work exposure is more relevant factor than age to study WMSDs.
Keywords: Ergonomics, manual miners, mechanized miners, stone mines, work-related musculoskeletal disorders
|How to cite this article:|
Nimje S, Dhatrak S, Nandi S. Comparative study of work-related musculoskeletal disorders among mechanized and manual stone miners. J Datta Meghe Inst Med Sci Univ 2020;15:287-91
|How to cite this URL:|
Nimje S, Dhatrak S, Nandi S. Comparative study of work-related musculoskeletal disorders among mechanized and manual stone miners. J Datta Meghe Inst Med Sci Univ [serial online] 2020 [cited 2021 Jan 16];15:287-91. Available from: http://www.journaldmims.com/text.asp?2020/15/2/287/304249
| Introduction|| |
Ergonomics (or human factors) is the scientific discipline concerned with the understanding of the interactions among human and other elements of a system, and the profession that applies theory, principles, data, and methods to design to optimize human well-being and overall system performance.
Work-related musculoskeletal disorders (WMSDs), which is a resultant demonstration of unergonomic working conditions and postures while performing mining activities, are defined as injuries or pain in joints, ligaments, muscles, nerves, tendons, and supporting structures of the neck, back, and limbs. Sudden exertion, maintenance of the same or non-neutral (awkward) posture over long time, making same motions repeatedly, and exposure to biomechanical load or force and vibrations are some of the causes of WMSDs in mine workers. Acute traumatic pain is not considered as MSD. Upper and lower back, shoulders, neck, and other body parts (arms, hands, legs, and feet) are the most common areas affected by MSD. The risk factors for WMSDs are lifting heavy weights, standing, sitting and bending for long hours, and continuous movements. WMSDs morbidity rate attributes toward high hospital expenditure, declining productivity, and lowering of physical quality of life. Lost work time, restriction to work, and unemployment are the ill consequences of WMSDs which are much higher than any other disease.,, WMSDs are caused during work and are one of the leading causes for man-hour's loss, also increases financial burden on person suffering, employer, and society. Usually, WMSDs are underreported as there is no mortality involved with it, but with increased awareness, the numbers of WMSDs may increase.
There are about 481.7 million workers in India as per the data given in the Indian Labor Yearbook 2015 (source office of registrar general India), of which 348.9 million workers are in the rural areas and 133.1 million workers in the urban areas of which unorganized sector accounts for 83% of the total workforce. There are about 3703 mines according to the Indian Bureau of Mines. However, it is known that many unreported minings are also prevalent in many parts of India, leading to unreported cases of MSD. Workers in mining industry are more susceptible to WMSDs as compared to other industry workers in resource-limited developing nations.
Stone mining is one of the contributors toward the economy of the country, with major contribution coming from Rajasthan and nearby areas. Rajasthan accounts for more than 90% of sandstone mining in India and engaging more than 25 lakhs mine workers. Stone mining is mostly carried out in unorganized small mines, and hence, data regarding the health hazards are not readily available.
It is important to study ergonomics because unergonomic working conditions have been known to cause musculoskeletal aches and pains. Ergonomic assessment, especially in miner workers, is important as the activities and the postures used to perform those activities could be one of the reasons for the prevalence of pain., It has been observed that workers are mostly illiterate, and the working conditions are relatively poor, and hence, prone for exposure to occupational health hazard.,
There are several studies on WMSDs conducted in various professional and nonprofessional groups such as municipal solid waste collectors, bus driver, manufacturing industry, brick field workers, farmers, and waste pickers.,,,,, However, very few studies have been conducted among mine workers, and hence, this questionnaire-based study was taken up to assess the WMSDs.,
| Materials and Methods|| |
The ergonomic assessment study was carried out among 889 stone mine workers in the state of Rajasthan, Uttar Pradesh, and Haryana. Professionals, managers, office staff, and workers with injury (past or recent) were excluded from study. The study was conducted after the approval of the Institutional Ethics Committee, and written informed consent was obtained from the participants. The study population was divided into two groups: one those working in mechanized mines (n = 363) and second group (n = 526) having workers mostly engaged in manual methods (primitive techniques).
Detailed data regarding the age, working experience, exposure to vibration, body parts involved, etc., were recorded by using the modified restructured questionnaire based on Nordic Questionnaire. The participants were interviewed in vernacular language, and data were entered in the questionnaire. The response of participants on their complaint of pain suffering from WMSDs was determined and graded to seldom, often, and never category. Data were analyzed using the Epi Info is statistical software for epidemiology developed by Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia (US), descriptive data as frequency and percentage. The association of age and work exposure to the occurrence of symptoms such as pain or discomfort was analyzed by univariate logistic regression.
Ethical approval for this study (NIMH/JNARDDC/2019-20/711) was provided by the Ethical Committee of National Institute of Miners' Health, on 22/4/2019.
| Results|| |
The distribution of mine workers according to age and work exposure is shown in [Table 1]. Among manual workers, majority, i.e., 55% of workers were above 40 years of age, whereas majority 65% workers among mechanized workers were below 40 years.
[Table 2] shows exposure to vibration, complain of pain, type of pain, etc., in respect to both the groups. [Table 3] shows the prevalence of musculoskeletal pain in relation to age and work in both the groups. While [Table 4] shows the risk ratio of WMSDs among the groups in relation to age and work exposure giving an assessment of unergonomic conditions in which the miners work.
|Table 3: Prevalence of musculoskeletal pain according to the age and work exposure|
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|Table 4: Risk ratio among the groups in relation to age and work exposure|
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| Discussion|| |
Mine workers are exposed to harsh conditions and stressful/awkward due to inefficient ergonomic position with repetitive and constant working activities that are predisposing factors for causation of WMSDs. It was seen that there was a high prevalence of musculoskeletal pain in these miners and the ergonomics while performing activities at mines was poor.
The work in the mining industry is basically divided according to mechanization involved in the extraction of ore. Nowadays, most of the mines do have a large amount of mechanization which has reduced injury levels among workers working there in. However, mechanization in stone mining industry is seen according to the extraction of stone being extracted. Mechanization is the highest in marble, granite, and metal stones and minimal in sandstone mining. As mine workers are prone to WMSDs due to highly physically demanding, the present ergonomic assessment study was conducted to compare WMSDs, resulting due to poor posture among manual and mechanized mine worker groups.
The present study was conducted among two groups one being manual workers (i.e., those miners working with chisels and hammers) and the second being mechanized miners (i.e., those miners using the machinery).
It was observed that majority of workers, i.e., about 66% in mechanized mines fall in the age group of 18–40 years. In terms of work exposure, for 0–10 years, 11–20 years, and >20 years in manual group exposure was 33%, 43%, and 23%, whereas it was 42%, 41%, and 15% in the mechanized group, respectively.
It was observed that vibration exposure was relatively higher among manual miners (62%) as compared to mechanized workers (45%), which show that vibration is relatively more due to striking of chisel with hammer as done in manual mines. Furthermore, manual lifting of heavy loads is common practice in manual miners with 73% miners engaged in it as compared to only 23% mechanized miners, and hence, complaining of pain a prerequisite to WMSDs due to unergonomic working conditions is observed mostly in manual miners (61%) as compared to mechanized miners (36%).
Further, when the type of pain in different regions such as the neck, upper back, lower back, and shoulder was studied, it was observed that combined pain, i.e., pain involved in two or more areas of the body more prevalent as seen in 40% of manual miners, whereas as it was 28% in mechanized miners indicating that the use to chisel and hammer leads to combined pain in various body parts. While the prevalent complain of lower back pain in mechanized miners (51%), brings to the fact that working with machinery is usually associated awkward position, repetitive performance of task, and the backlash and vibration received by the miner.
The relation of age and work exposure with WMSDs is directly proportional and statistically significant in both the groups. This indicates as the age and work exposure increases, there is an increase in the proportion of WMSDs among the workers. Various studies have been conducted on WMSDs among miners in which similar finding was observed. In one of the study conducted in Chinese coal workers, the prevalence of WMSDs was found to be 78%; the prevalence of WMSDs in informal miners in Brazil was found to be 61%; and the prevalence of WMSDs in Iranian coal miners was found to be 67%.,, In Indian studies, also the prevalence was 65% in coal mine sand was 81% in sandstone miners in India.,
The most affected body parts in WMSDs include the wrist/hand, lower back, and neck.,, Increased age is a higher risk factor for WMSDs as muscle groups and tendon become more vulnerable to stress, osteoporosis sets up in the bones making them vulnerable to fractures, working stamina also reduces and so do other physical parameters of the body, studies have found this relationship of WMSDs with age in South Africa (odds ratio [OR] =2.3; 95% confidence interval [CI] 1.9–2.7) and Ghana (OR = 2.07; 95% CI 0.99–4.34)., Similar findings suggesting that age is a risk factor in India; studies conducted are coal miners, construction workers, and textile workers.,, However, in the age group of 41–50 and 51–60 years, the prevalence of WMSDs is similar thus indicating that WMSDs are mostly because of work exposure.
When the RR of WMSDs were studied in relation to manual and mechanized workers, it was observed that the risk ratio to the age group of 18–40, 41–50, and 51–60 years is 2.56, 2.25, and 2.76, respectively, indicating that manual workers are much more prone for WMSDs. Similarly, when the RR of WMSDs were studied in relation to manual and mechanized workers, it was observed that the risk ration to the work exposure of 0–10, 11–20, and >20 years is 3.38, 2.17, and 2.59, respectively, again indicating that manual workers are much more prone for WMSDs. All these results indicate that all the groups in question are highly statistically significant, which leads us to the fact that the prevalence of WMSDs in manual miners is greater than those who are mechanized miners, in term of both age and work exposure. Miners of the older age group have a highest median number of lost days per injury, due to their greater work exposure to substantially challenging work and elongated time period for recovery. Simultaneously, such miners have a comprehensive understanding of work and can prospectively make noticeable propositions to enhance the mining process, i.e., make it innocuous and more proficient. Decreasing WMSD risk factors will augment the superior life of miners, have an encouraging consequence on the productive capability of the mining proposal, and reduce curative expenditures connected with mine process.
Being a subjective questionnaire study, the result may be false-positive or false-negative. A questionnaire study along with the clinical assessment and few investigations will yield better results.
On the basis of study findings, it is recommended that attempts should be taken to switch the manual working to mechanical which will minimize the occurrence of WMSDs in susceptible miners. Jacobs et al. study showed that 6 years of ergonomic education resulted in reduced incident of musculoskeletal pain. This study also proved the association between unergonomic working conditions and occurrence of musculoskeletal disorders, mechanization will also lead to ease of doing work, and also help in preventing the loss of working days in these miners; this will also decrease the economic burden on society, individual and the mining industry. However, it has also been observed that complain of lower back pain is more prevalent in mechanized workers indicating that machinery used by them in drilling is ergonomically not efficient resulting in rise in WMSDs in a young age group as well. Musculoskeletal health problems exist in miners in both the groups. Mine workers also demonstrated unergonomic behavior with most of the activities at mines. It is important to identify the health problems at an early stage in mine workers, so that chronic health ailments could be prevented. Miners are routinely screened every 3–5 years, but due the fact that WMSDs symptoms not being part of their compulsory medical examination; mostly, this area is skipped which is worrisome finding, as it may affect their ability to work efficiently and stay healthy, to prevent the loss of working hours/days. It is recommended that all the miners must be screened periodically, and examination of WMSDs with X-ray spine and use of electromyography and nerve conduction velocity should be made compulsory.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
International Ergonomic Association. The Discipline of Ergonomics. Human Factors; 01.January, 2000. Available from: http://www.iea.cc/ergonomics/.
[Last accessed on 2019 Nov 18].
Kuorinka I, Jonsson B, Kilbom A, Vinterberg H, Biering-Sørensen F, Andersson G, et al
. Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Appl Ergon 1987;18:233-7.
Hoozemans MJ, Kuijer PP, Kingma I, van Dieën JH, de Vries WH, van der Woude LH, et al
. Mechanical loading of the low back and shoulders during pushing and pulling activities. Ergonomics 2004;47:1-8.
Karwowski W, Marras WS. Occupational Ergonomics: Principles of Work Design. Florida: CRC Press; 2003.
Badley EM, Rasooly I, Webster GK. Relative importance of musculoskeletal disorders as a cause of chronic health problems, disability, and health care utilization: findings from the 1990 Ontario Health Survey. J Rheumatol 1994;21:505-14.
Riihimäki H. Hands up or back to work-future challenges in epidemiologic research on musculoskeletal diseases. Scand J Work Environ Health 1995;21:401-3.
Leijon M, Hensing G, Alexanderson K. Gender trends in sick-listing with musculoskeletal symptoms in a Swedish county during a period of rapid increase in sickness absence. Scand J Soc Med 1998;26:204-13.
Kemmlert K. Labour Inspectorate Investigation for the Prevention of Occupational Musculoskeletal Injuries (Licentiate Thesis). Solna, Sweden: National Institute of Occupational Health; 1994.
IBM. Indian Minerals Yearbook 2013 (Part III: Minerals Reviews) 52nd
ed. Nagpur: Maharashtra, India; 2015.
Dianat I, Javadivala Z, Allahverdipour H. School bag weight and the occurrence of shoulder, hand/wrist and low back symptoms among Iranian elementary schoolchildren. Health Promot Perspect 2011;1:76-85.
Jacobs K, Kaldenberg J, Markowitz J, Wuest E, Hellman M, Umez-Eronini A, et al
. An ergonomics training program for student notebook computer users: Preliminary outcomes of a six-year cohort study. Work 2013;44:221-30.
Marimuthu P, Meitei MH, Sharma B. General morbidity prevalence in the Delhi slums. Indian J Community Med 2009;34:338-42.
] [Full text]
Basnet P, Gurung S, Pal R, Kar S, Bharati DR. Occupational stress among tunnel workers in Sikkim. Ind Psychiatry J 2010;19:13-9.
] [Full text]
Abou-Elwafa HS, El-Bestar SF, El-Gilany AH, Awad Eel-S. Musculoskeletal disorders among municipal solid waste collectors in Mansoura, Egypt: A cross-sectional study. BMJ Open 2012;2:100-6.
Sandul Y, Paramasivan R. Indian J Occup Environ Med 2014;18:75-81.
Carrillo-Castrillo JA, Rubio-Romero JC, Guadix J, Onieva L. Risk assessment of maintenance operations: The analysis of performing task and accident mechanism. Int J Inj Contr Saf Promot 2015;22:267-77.
Das B. Assessment of occupational health problems and physiological stress among the brick field workers of West Bengal, India. Int J Occup Med Environ Health 2014;27:413-25.
Gupta G. Prevalence of musculoskeletal disorders in farmers of Kanpur-rural, India. J Community Med Health Educ 2013;3:1-4.
Singh S, Chokhandre P. Assessing the impact of waste picking on musculoskeletal disorders among waste pickers in Mumbai, India: A cross-sectional study. BMJ Open 2015;5:e008474.
Xu, G, Li, L, Liu, F, Pei, D, Wang S. Mus-culoskeletal disorders and risk factors of workers in a coal mine. Chin J Industrial Hygiene Occup Dis 2011;29:190-3.
NunesAlves de Sousa M, de Oliveira Santos BM, Zaia JE, Bertoncello D, do Nascimento An-dradeFeitosa A, de Assis V, et al
. Musculoskeletal disorders in infor-mal mining workers. Int Arch Med 2015:1-8.
Aghilinejad M, Kabir-Mokamelkhah E, Nassiri-Kashani MH, Nouri MK, Noorian N, Ahmadi AB. Musculoskeletal disorders among iranian coal miners. Iran J Health Safety Environ 2014;3:466-4.
Bandyopadhyay A, Dev S, Gangopadhyay S. A study on the prevalence of musculoskel-etal disorders among the coalminers of Eastern Coalfields of India. Int J Occup Safety Health 2012;2:34-7.
Ahmad A, Alvi R. Musculoskeletal disorders (MSDs) and risk factors of workers in Indian mining industry: A cross-sectional study. Int J Percep Pub Health 2017;1:241-8.
Kunda R, Frantz J, Karachi F. Prevalence and ergonomic risk factors of work-related musculoskeletal injuries amongst underground mine workers in Zambia. J Occup Health 2013;55:211-7.
Bio F, Sadhra S, Jackson C, Burge P. Low back pain in underground gold miners in ghana. Ghana Med J 2007;41:21-5.
Reddy GM, Nisha B, Prabhushankar TG, Vishwambhar V. Musculoskeletal mor-bidity among construction workers: A cross-Sectional community-Based study. Indian J Occup Environ Med 2017;20:144-9.
Tiwari RR, Pathak MC. Low back pain among textile workers. Indian J Occup Environ Med 2003;7:27-9. [Full text]
Fotta B, Bockosh GR. The aging workforce: An emerging issue in the mining industry. In: Bockosh G R, Karmis M, Langton J, McCarter MK, Rowe B, es. Proceedings of the 31st
Annual Institute of Mining Health, Safety and Research. Blacksburg, VA: Virginia Polytechnic Institute and State University, Department of Mining and Minerals Engineering. 2000. p. 33-45.
[Table 1], [Table 2], [Table 3], [Table 4]