The disease and disorders which are the result of workplace are called "workplace problems". These problems are recognized when the incidence of a special problem among the specific group of workers become more than the public population. Musculoskeletal injury is one of these problems, for which there is no compensation in most countries (1). Annually, about 500000 workers in the USA suffer from injuries which are the result of hard working. About 60% of these injuries have occurred during lifting and 20% during pushing and pulling. (2). Around 30% to 50% of workers may face the risk of death (3). Working in hard and disturbing position could cause temporary problems in the whole body and with the passage of time it may lead to musculoskeletal and peripheral nervous problems and even disability. Thus; improper workplace lacking work standards could cause many problems and disorders. (4). Despite the focus on public awareness about occupational health, studies show that occupational injuries in librarians are increasing. In Washington, 50% of injuries lead to 85% of spending costs. Also 88% of these injuries are nonemergency; it means that these injuries appear with the passage of time, for example; Backache and wrist tunnel syndrome. (5). Studies show that musculoskeletal injury related to occupation may cause to waste time, increase costs and human sources injury and ergonomists through the world face these issues. (3). Unfortunately, managers are not usually aware of improper workplace which can reduce the yielding. Workers adapt themselves to inappropriate conditions but the costs of this adaptation are: increase in work time, decrease in work quality, increase in the injures (6) and decrease in health rate and quality of life. By using techniques that are able to analyze the workstation ergonomically, we can prevent these occupational injuries and improve yielding, thus the organization can achieve competitive qualities. (7) Some libraries such as Princeton library in the USA do some supporting effort for improving occupational health through their specific programs. This program is a tool for the recognition of risk factors that threat the university stuffs, a copy of this program is presented to all of the librarian (8). But the condition of other libraries specially the developing countries and more specifically the condition of public libraries are not recognized. There is a need for more evidence for managers and people in charge to clear the importance of ergonomic factors for all of the managers and principals, so that they can plan the suitable program both to improve yielding and guarantee librarians's health. To create evidence and highlight the significance of the issue in this study we investigated public libraries situation in Hamadan city of Iran as a sample of a developing country context. Thus; the aim of this study is to investigate the effect of ergonomic factor on the incidence of musculoskeletal injury in librarians in Hamadan public libraries.
2. Literature Review
A review of literature on workers' ergonomic condition in related data base such as: Science Direct, SID (www.Sid.ir), Pub Med and Google Scholar show that there are many investigations about ergonomic factors in workplaces in industrial area. Therefore; we focus on the effect of ergonomic factors on the health in libraries. We include only the literature about the ergonomic factors and their relation with the incidence of musculoskeletal problems. Folad Dehghi's conducted a study among 300 workers in production in a household equipment industry with 150 men and women workers. In his study the QEC method (screening tool for ergonomic risk in musculoskeletal system) was used for evaluating the effect of occupational risk factors on the body. Both QEC method, and the Nordic questionnaire are used. The results show that 85.3% of workers have musculoskeletal problems but only 25.3% of whom consulted a physician. (9).
The results of another study in lab workers in teaching hospitals in Kermanshah University showed that workstations are improper and 91. 9% of workers have no suitable workplace. The study used the Nordic questionnaire for the evaluation of ergonomic factors (10). Another study about ergonomic conditions of libraries showed that those who work more than 3 hours a day face visual, joint and skin problems, also they have joint pain and stress. They suffer from epilepsy because of sensitivity to light. One of the disadvantages of this study is that there is no reference to any method (11). Alamolhodai studied the ergonomic factors in workplace along with problems related to working by computer in 13 librarians in central libraries in the universities of Tehran. Results showed that in these libraries most of workers work with computer more than 3 hours a day. In 60.6% of libraries there is no turn in work, 72.7% of them have suitable position when working with computer and 42,6% of them face work problems. In this study the Nordic questionnaire and the check list based on OSHA and NYOSH standard are also used (12). In the study in librarians in library in Cornell University, the results showed that when the paper lists were changed into computerized ones, 25% of librarians were in therapeutic condition. And more than 70% of them changed their workplace. At the time there is no standard for workplace and workstation (13). Adeym (2010) studied the ergonomic condition in librarians, library stuffs and system engineers in Logos and Covenant University. His study indicated that in both universities there are ergonomic problems such as: stretch, pressure, headache and other problems. Most of these problems are the result of unsuitable chairs, hard working, unsuitable position and having no support for computer screen (14). In another study in Cornell university about 58 libraries, the results showed that in about half of the sample (44.7%), only 1 staff faced occupational problems and in 55. 7% of them at least once a week, faced occupational problems (15). Studies about the literature reviews showed that there is not enough investigation about the effect of ergonomic factors on musculoskeletal disorders in librarians especially in Iran. The review of study showed that there is no study about the effect of ergonomic factors on the musculoskeletal injuries in public libraries...