Year : 2021  |  Volume : 25  |  Issue : 4  |  Page : 204--208

Corrective exercises or ergonomic principles for workers with low back pain

Alireza Safaeian, Armindokht Shahsanai, Farzaneh Kiyany 
 Department of Community and Family Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Correspondence Address:
Dr. Farzaneh Kiyany
Department of Community and Family Medicine, School of Medicine, Isfahan University of Medical Sciences, Hezar Jabib Blv. Isfahan


Introduction: Work-related musculoskeletal disorders (WRMSD) are considered the main cause of occupational diseases. Health care workers, nursing assistants, and service forces that perform manual labor are the most vulnerable to musculoskeletal disorders, especially low back pain, due to the nature of their jobs. The purpose of this study was to compare the effectiveness of corrective exercise training to ergonomic principles training on low back pain in nursing assistants and service forces. Methods: A nonrandomized clinical trial study was done on 75 staff (nursing assistants and service forces) with low back pain. The participants were divided into three groups: corrective exercise training, ergonomic principles training, and control group. Pain intensity and disability questionnaires were completed before and after 8 weeks of intervention by each group and analyzed. Results: The mean intensity of pain after intervention in corrective exercises group (3.8 ± 1.5) was markedly less than the ergonomic group (4.7 ± 1.4) and control group (5.5 ± 1.7) (P = 0.001). The mean disability score after intervention in the corrective exercises group (17.3 ± 9.6) was significantly less than the ergonomic group (21.8 ± 12.6) and control group (25.3 ± 11.2) (P < 0.001). Conclusion: While corrective exercises training and ergonomic principles training both have a significant effect on reducing the severity of pain and disability caused by low back pain, corrective exercises training is more effective than ergonomic principle training.

How to cite this article:
Safaeian A, Shahsanai A, Kiyany F. Corrective exercises or ergonomic principles for workers with low back pain.Indian J Occup Environ Med 2021;25:204-208

How to cite this URL:
Safaeian A, Shahsanai A, Kiyany F. Corrective exercises or ergonomic principles for workers with low back pain. Indian J Occup Environ Med [serial online] 2021 [cited 2022 May 26 ];25:204-208
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Full Text


Work is an integral part of human life, but rapid development and the growth of industries through the advancement of technologies has created occupational hazards like manual labor injuries along with increasing complications of the related diseases. One of the most common work-related musculoskeletal disorders is low back pain, which not only is one of the most common medical problem which necessitates frequent doctor visits but also is one of the costliest expenses for the insurance companies as well as the government.[1],[2]

Musculoskeletal disorders are caused by heavy load manual labor over time and are the most common cause of missed workdays and loss of productivity.[3]

The cost of musculoskeletal disorders is estimated to be about 1% of the gross national product of industrialized countries.[4]

Studies show that musculoskeletal disorders in health care workers are more prevalent than workers in construction, mining, and manufacturing.[5]

The Ministry of Health provides health care services, and health care workers with different specialties work in various departments to provide high-quality healthcare services to clients. Hence, physically and psychologically healthy personnel, high-quality equipment, and financial resources are needed.[6]

Research shows a different incidence of musculoskeletal disorders in various jobs and the decisive role of corrective exercise as well as ergonomic principles on reducing these disorders.[7],[8]

Over the past decades, some studies have shown that exercise programs and ergonomic intervention are effective for the prevention and treatment of musculoskeletal disorders.[9],[10]

According to our research, there are not many studies on comparing the effects of corrective exercises training and the ergonomic principles training in improving low back pain of nursing assistants and service staff. Therefore, this clinical trial was conducted to compare the effect of these two methods on reducing the severity of low back pain and disabilities arising from said pain.


A convenience nonrandomized clinical trial was designed. According to the sample size formula, with 95% confidence interval, power of 80%, and by study of Hemmati et al.,[11] with standard deviation of pain intensity, 1.16 and 1.08, the mean difference error 1.33 (3.91–2.25), and the estimated attrition rate of 10%, the sample size was 75 subjects, which were equally divided into three groups. For prevention of contamination, samples were selected from three different hospitals.

Inclusion criteria

The participants should have at least 1 year of work experience in hospital, reading and writing capability, a history of low back pain over the past 3 months, no specific low back pain such as infection, rheumatoid diseases, congenital malformations, history of cancer, vertebral fractures, and spinal tumor based on Occupational Health Records. Participants should be capable of exercising. Complete a written and signed informed consent form to participate in the study.

The intensity of pain was assessed by the visual analogue scale (VAS) from zero (painless) to ten (maximum pain).[12],[13]

The Oswestry low back pain and disability questionnaire was used to assess the functional disability of the participants. The questionnaire consists of 10 parts: assessment of pain intensity in personal activities such as lifting, walking, sitting, standing, sleeping, sexual activity, social life, and travel, and each section includes six options (minimum 0 and maximum 10) and the degree of disability in performance is from zero (optimal performance without pain) up to 10 (the inability to perform activities because of severe pain). A higher score means greater disability. The total score for each section is ten and the overall disability score is between 0 and 100.[14]

Samples were selected based on occupational health records and inclusion criteria by convenience sampling. Subjects were divided into three groups of 25 persons randomly. The first group was in the ergonomic training program, the second group was in corrective exercises training program, and the third group as the control that received no intervention [Figure 1].{Figure 1}

Before the intervention, the demographic and occupational variables checklist and the standard Oswestry questionnaire for assessing the disability of the back pain in performing daily activities were completed and low back pain intensity assessed by VAS. The first group had a 30-min face to face ergonomic principle training and pamphlets provided by the researcher under the supervision of an occupational medicine specialist. The second group had a 30-min face to face corrective exercise training and pamphlets contained images, duration, and method for exercising provided by the researcher under the supervision of sports medicine specialist.[2] For the third group, only the questionnaires were completed before and after 8 weeks. For ethical reasons, the pamphlets were given to this group after completing the second questionnaire. The continuation of intervention (regular exercise and ergonomic principles) at home and the workplace was followed up by researchers via SMS three times a week. The intensity of pain (VAS) reduction and functional disability (Oswestry questionnaire) were assessed in the corrective exercise group after an 8-week follow-up (40–60 min exercise in each session three times a week), and in the ergonomics training group after 8 weeks observing the ergonomic principles, the similar assessment was performed. Data was analyzed with SPSS software version 21. The statistical tests used in this study were one-way ANOVA and Chi-square.


We surveyed seventy-five nursing assistants and service forces in 3 groups of 25, 100% completed the questionnaire. As shown in [Table 1], the three groups did not have a significant difference in age and work history. Chi-square test showed that the frequency distribution of sex (P = 0.48) and job title (P = 0.69) were not significantly different between the three groups [Table 1].{Table 1}

One-way ANOVA showed that there was no significant difference in the mean pain score before intervention between the three groups (P = 0.48). The mean score of pain intensity was significantly different between the three groups (P = 0.001). The mean score of pain intensity after intervention in the exercise group was less than the ergonomic group, and the ergonomic group was less than the control group [Table 2].{Table 2}

The ANOVA analysis test in the three groups showed that after the intervention, the mean disability scores between the three groups were significantly different (P < 0.001). The mean score of disability after intervention in the exercise group was less than the ergonomic group and in the ergonomic group was less than the control group [Table 3].{Table 3}


This study showed that the mean pain intensity and disability level after intervention in corrective exercises training group was significantly less than the ergonomic and control groups. This significant difference was observed in a randomized controlled clinical trial by Mohseni-Bandpei on the chronic low back pain of 236 nurses in Mazandaran province, which is in line with the results of our study.[2]

The study of Ali Arabian studying the effect of ergonomic principle training on musculoskeletal disorders in 46 hospital staff showed that the training of ergonomic principles did not have a significant effect on the reduction of musculoskeletal disorders. This difference with our study may be because of low sample size and sample selection of only women in emergency departments and operating rooms with heavy workloads.[15]

In 2014, Aghilinejad et al. conducted a study to investigate the effect of ergonomic training on low back pain on 451 workers at Iran Khodro Factory, which after 1 year had a significant impact on musculoskeletal disorders that is in line with the results of our study.[16]

In the study of Alexandre et al., the effect of exercise on the prevention of low back pain in nurses and the study of Hemmati et al., the effect of central stabilizer training on the severity of pain and disability in 24 nonspecific chronic low back pain patients was observed after follow-up of low back pain, which results are line with the results of this study.[11],[17]

In the study of Soukup et al., observance of the ergonomic principle and the implementation of corrective exercise increased physical ability and reduced pain in patients, which is in line with the results of this study.[18]

In the study of Niemisto et al., the effect of therapeutic exercise on relief of back pain compared with other therapies such as manual maneuvering by physicians and medical counselling for ergonomic principles as a randomized clinical trial that introduced the effect of therapeutic therapy more effectively and better than other methods, which is in line with the results of this study.[19]

In the studies of Garcia et al. and Taheri et al., the effect of the lumbar health training program and McKenzie method on low back pain has been effective, which is in line with the results of this study.[20],[21]

In the studies of Sadeghian et al. and Fanucchi et al., regular exercise had a positive effect on the prevention of low back pain, meaning that the exercise samples had less back pain; the results were consistent with this study.[22],[23]


The results showed that corrective exercise training has a better effect on the low back pain of nursing assistants and service forces than ergonomics principles training.


Further studies are necessary to support our findings. Even so, our recommendation is that managers of hospitals to pay more attention to corrective exercise training courses for personnel.


We could not select samples randomly because of a limited number of staff members with low back pain as well as a small number of available hospitals for intervention.

This trial is registered with the Iranian Registry of Clinical Trials (Registration ID: IRCT20171230038142N).


We thank occupational hygienists of Al-Zahra, Kashani, and Khorshid hospitals in Isfahan, Iran for their cooperation and Khosrow Saedinia for his editorial assistance in English.

Declaration of participant consent

The authors certify that they have obtained all appropriate participant consent forms. In the form, the participants have given their consent for their images and other clinical information to be reported in the journal. The participants understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This study was granted by Isfahan University of Medical Sciences.

Conflicts of interest

There are no conflicts of interest.


1Levy BS, Wegman DH, Baron SL, Sokas RK. Occupational and Environmental Health: Recognizing and Preventing Disease and Injury. 5th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006. p. 488-516.
2Mohseni-Bandpei MA. Chronic low back pain: A randomized controlled trial of spinal manipulation measuring pain, functional disability, lumbar movements and muscle endurance using surface electromyography (Doctoral dissertation, University of East Anglia); 2000. p. 8-15.
3Barkhordari A, Ketabi D, Mirrmohammadi SJ, Fallahzadeh H, Mehrparvar AH. Prevalence of work-related musculoskeletal disorders in auto parts- manufacturing plants' workers. J Toloo-E-Behdasht 2012;11:77-87[Article in Persian].
4McClune AJ, Conway A. Farm safety: A tale of translational research and collaboration. Pediatr Nurse 2016;42:31-5.
5Ngan K, Drebit S, Siow S, YU S, Keen D, Alamgir H. Risks and causes of musculoskeletal injuries among health care workers. Occup Med 2010;60:389-94.
6Zarei F, Rajaei B, Nikpey A, Varmazyar S, Safari-Variani A. Review the proportion of university seats with body dimensions of students at the School of Public Health of Qazvin University of Medical Sciences in 2009. Iran Occup Health 2011;8:40-7.
7Kim HJ, Nam SN, Bae UR, Hwang R, Lee JB, Kim JH. The effect of 12 weeks prop pilates exercise program (PPEP) on body stability and pain for fruit farmers with MSDs. Technol Health Care 2014;22:359-67.
8Rahnama N, Bambaeichi E, Ryasati F. The effect of eight weeks corrective exercise with ergonomic intervention on musculoskeletal disorders among loabiran industry workers. J Isfahan Med Sch 2010;28:316-26.
9Janbozorgi A, Rahnama N, Ghasemi Gh, Afzalpour ME, Ilbeigi S, Karimian R. Effect of 8 weeks corrective exercises on musculoskeletal disorders in Isfahan's, Iran, teachers with an ergonomic intervention. J Health Syst Res 2013;9:521-30.
10Andersen CH, Andersen IL, Mortensen OS, Zebis MK, Sjogaard G. Protocol for shoulder function training reducing musculoskeletal pain in shoulder and neck: A randomized controlled trial. J BMC Musculoskeletal Disord 2011;12:1-5.
11Hemmati SH, Rajabi R, Karimi N, Jahandide A. Effect of central stabilization exercises intensive and under the control of pain and disability of women with non- specific chronic low back pain. Koomesh 1390;3:224-53.
12Nuri S, Ghasemi GHA, Karimi A, Salehi H. Comparing the effect of exercise therapy and self-treatment through “the back book” on chronic low back pain. JRRS 2011;7:179-87.
13Sadat Larrie M, Bakhtiary AH, Hedayati R, Rezasoltani A, Ghorbani R. Comparison the effect of stabilization and McKenzie exercise on pain, disability and lumbar multifidus muscle size in women with chronic non-specific low back pain. JRRS 2012;8:11-9.
14Mousavi SJ, Parnianpour M, Mehdian H, Montazeri A, Mobini B. The Oswestry disability index, the Roland-Morris disability questionnaire, and the Quebec back pain disability scale: Translation and validation studies of the Iranian versions. Spine 2006;31:E454-9.
15Ali Arabian F. The effect of ergonomic intervention on the skeletal-muscular dislocation of hospital workers. Q J Ergonom 1396;4:23-32.
16Aghilinejad M, Bahrami-Ahmadi A, Kabir-Mokamelkhah E, Sarebanha S, Hosseini HR, Sadeghi Z. The effect of three ergonomics training programs on the prevalence of low-back pain among workers of an Iranian automobile factory: A randomized clinical trial. Int J Occup Environ Med 2014;5:65-71.
17Alexandre NM, de Moraes MA, Correa Filho HR, Jorge SA. Evaluation of a program to reduce back pain in nursing personnel. Rev Saude Publica 2001;35:356-61.
18Soukup MG, Lonn J, Glomsrod B, Bö K, Larsen S. Exercises and education as secondary prevention for recurrent low back pain. Physiother Res Int 2001;6:27-39.
19Niemisto L, Lahtinen-Suopanki T, Rissanen P, Lindgren KA, Sarna S, Hurri H. A randomized trial of combined manipulation, stabilizing exercises, and physician consultation compared to physician consultation alone for chronic low back pain. Spine 2003;28:2185-91.
20Garcia AN, Costa Lda C, da Silva TM, Gondo FL, Cyrillo FN, Costa RA, et al. Effectiveness of back school versus McKenzie exercises in patients with chronic nonspecific low back pain: A randomized controlled trial. Phys Ther 2013;93:729-47.
21Taheri H, Soltani M, OmidAli Z. The effects of back school program on back pain and disability in students of police university with chronic nonspecific low back pain. J Forensic Med 1394;3:224-53.
22Sadeghiyan F, Kallalian Moghadam M, Javanmard M, Khosravi A, Adelnia S. An epidemiological survey of low back pain and its relational and personal factors among nursing personnel at hospitals of Shahrood. Iran South Med J 2005;8:57-82.
23Fanucchi GL, Stewart A, Jordaan R, Becker P. Exercise reduces the intensity and prevalence of low back pain in 12-13 year old children: A randomized trial. Aust J Physiother 2009;55:97-104.