musculoskeletal disorders are one of the most common causes of occupational injuries and disability in industrialized nations and developing countries ( 1 - 3 ) . a variety of risk factors are involved in the occurrence of the damage that can be divided by physical factors such as poor posture , ergonomics , lifting , and carrying heavy loads and working with repetitive movements ( 4 ) , psychological , organizational , and individual factors ( 5 ) . these disorders mainly occur in the upper extremities such as hands , wrists , arms , shoulders , neck , and waist ( 6 ) . these disorders occur due to repetitive movements that led to the injury of nerves , tendons , joints , cartilage or disks between the vertebrae ( 7 ) . factors that cause these disorders are awkward posture , repetitive movements , and excessive force . the signs of musculoskeletal symptoms are muscle pain , discomfort , numbness down , burning , tenderness , swelling , limited range of motion , and loss of power . a long repetitive movement of the body ( 8) causes these pains . according to the previous studies , there is a significant relationship between musculoskeletal disorders and repetitive motion . several professionals such as surgeons and personnel of the operating rooms are at risk of these symptoms . the surgeons perform the surgery in a standing position , and the hands are generally in motion in surgery . sometimes a fixed posture continues for hours and the pressure exerted by the musculoskeletal organs is too high ( 11 ) . over time , the continuous exposure to biomechanical and psychosocial stressors may intensify the musculoskeletal injuries in the workplace . because surgery is often subtle , sensitive , and time - consuming , ergonomics aims at helping the surgeons to work without feeling any pain , or stress , and with less error ( 12 ) . nowadays , various surgical procedures are done such as open surgery , laparoscopy , and microsurgery ( 13 ) . the body posture of the surgeons during open surgeries is described as a head - bent and back - bent posture . surgeons maintain this posture for long periods ; and as a result , they experience physical discomfort during and after the surgery ( 13 ) . during laparoscopic procedures , the body movement of the surgeon is very limited , resulting in a more static upright body posture compared to open surgery ( 13 ) . due to the position and depth of the incision during open surgery , surgeons have a fixed work posture , tending to work with arms abducted and unsupported ( 14 ) . for instance , repetitive motion of the wrist in laparoscopic surgery , and neck static posture in microsurgery could cause musculoskeletal disorders ( 14,15 ) . in addition to improper posture due to ergonomics , repetitive movements of the hands and wrists , neck and shoulders , and excessive force can ultimately cause or exacerbate these effects ( 16 ) . according to healthcare professionals , multiple ergonomic risk factors in the operating rooms can lead to or aggravate musculoskeletal symptoms . moreover , no comprehensive study has been conducted to evaluate and compare the ergonomic risk factors in these 3 types of surgeries . this study aimed at evaluating the role of various ergonomic risk factors in the frequency or resonance frequency of musculoskeletal symptoms in surgeons who perform surgery ( open surgery , laparoscopy , and microsurgery ) in a hospital of iran university of medical sciences . eighty - one male surgeons who consistently worked at milad hospital in tehran participated in this study . each of these surgeons exclusively conducted one of the 3 types of open surgery , laparoscopy , and microsurgery . after interviewing the surgery team , to determine the prevalence of musculoskeletal symptoms , the nordic questionnaire ( a questionnaire made by kurinka et al . at the institute of occupational health in 1987 ) was used ( 17 ) . in this study demographic information such as age , height , weight , work experience , and number of hours per day were added to the questionnaire . to estimate and evaluate the ergonomic risk factors in each of these three types of surgery wera method was used . the wera covers an extensive range of physical risk factors including posture , repetition , forceful , vibration , contact stress , and task duration , and it assesses the five main body regions ( shoulder , wrists , back , neck and legs ) ( 18 ) . eighty - one surgeons who performed the 3 following types of surgeries participated in this study : open surgery ( n=26 ) , laparoscopy ( n=28 ) , and microsurgery ( n=27 ) . each of the surgery types was observed using the wera tool . during the surgery , observation of the workplace was carried out by recording the surgeries using a video camera . the three types of surgery were observed and videotaped to collect data for the wera assessment . the angle of the body segments relative to the vertical position was estimated ( shoulders , wrists , back , neck and legs ) using the video tapes ( 18 ) . the participants were middle aged and experienced ( 5.4 years of work experience ) . table 2 demonstrates the prevalence of musculoskeletal disorders that the surgeons experienced during the past 12 months . the prevalence of symptoms in the neck , back , shoulder , and arm was high ; and a high percentage of the participants involved in all the 3 types of surgeries ( open surgery , laparoscopy , and microsurgery ) . no significant difference was found in the prevalence of musculoskeletal symptoms in the body of the surgeons performing these 3 types of surgeries . 
  * friedman two - way analysis of the variance test 
 table 3 displays the evaluations of the wera scores . the average of wera final score is 40.11 , representing an upward risk for musculoskeletal disorder in 3 types of surgeries . in this study , the wera score of laparoscopic surgery had a significant relationship with back problems ( r=0.61 , p=0.02 ) , wrist ( r=0.53 , p=0.03 ) , and neck ( r=0.49 , p=0.02 ) . musculoskeletal disorder had a significant relationship with the wera score ( r=0.48 , p=0.02 ) in open surgery , and ( r=0.46 , p=0.04 ) microsurgery . the aim of this study was to evaluate the relation of musculoskeletal disorders and ergonomic risk factors based on wera method in 3 types of surgery among the surgeons who were working in tehran 's hospitals . 
 
 in this study , it was found that specified ergonomic risk factors , based on evaluating by wera , has a high impact on the prevalence of musculoskeletal symptoms . on the other hand , the type of surgery was the main cause of musculoskeletal disorders among surgeons who participated in this study . in a study on the prevalence of musculoskeletal symptoms in surgeons , it was found that the highest prevalence was in the lower back , neck , and hands due to poor postures of the surgeons during surgery ( 19 ) . in another study , the most important cause of arthritis pain and disability was found to be long - term operating mode or standing back for long hours ( 11 ) . therefore , the results of this study are consistent with those of the previous studies on the prevalence of musculoskeletal symptoms in surgeons . musculoskeletal disorder is more common in laparoscopic surgery and open surgery due to incorrect posture , such as the need to bend neck and back ( 20 ) . on the other hand , the prevalence of musculoskeletal symptoms in wrist of the surgeons had a direct relationship with instruments in this study , which is consistent with the results of previous studies ( 21 ) . improper use of hand tools in the surgery caused musculoskeletal symptoms and back pain , especially in awkward postures ( 22 ) . in a study conducted on surgeons , the most complaints of the surgeons were related to limbs shoulder , wrist , and waist ( 23 ) . in another study , the highest prevalence was in the back , neck , and wrists , causing adverse deviation of the wrist posture from the normal posture ( 24 ) . 
 
 among the most important tools used in laparoscopic surgery is grasper / loop , which causes poor posture of the body . in addition , looking into a monitor for a long time increases the risk of musculoskeletal symptoms in laparoscopic surgeries in the cervical region ( 25 ) . moreover , working with the surgical microscope for a long - time , improper postures , and improper seating increase the prevalence of musculoskeletal symptoms in the back and neck muscle areas while performing microsurgery ( 26 ) . the results of this study revealed that the prevalence of musculoskeletal symptoms was high among the surgeons . therefore , it is necessary to take action to solve this problem by using appropriate ergonomic tools , management solutions , and suitable design of surgical instruments . a standing - sitting ergonomic chair could be used to prevent back pain in open surgery . moreover , using a suitable chair can prevent improper postures . to prevent wrist musculoskeletal symptoms , surgical tools with ergonomic design and soft rubber handle depending on the type of surgery training , using appropriate seats and ergonomic instruments are the best solution to reduce musculoskeletal symptoms in the surgeons . the results of this study revealed that the prevalence of musculoskeletal symptoms was high in 3 types of open surgery , laparoscopy , and microsurgery among the surgeons . in addition , it was found that these symptoms were more prevalent in the neck , waist , and hands . depending on the type of surgery , teaching appropriate methods , using equipment properly , and using proper ergonomic seats are the best strategy to reduce musculoskeletal symptoms in surgeons .
background : musculoskeletal symptoms are the main cause of loss of working time , and increase in labor costs . 
 poor posture is the most important risk factor for work - related musculoskeletal symptoms . 
 this study aimed at evaluating the role of ergonomic risk factors in different surgical ( open surgery , laparoscopy , and microsurgery ) in the frequency or resonance frequency of musculoskeletal symptoms . 
 methods : this descriptive - analytic study was conducted on 81 surgeons in a hospital in tehran . in this study , the prevalence of musculoskeletal symptoms was evaluated using the nordic questionnaire 
 . moreover , workplace ergonomic risk assessment method ( wera ) was used to evaluate ergonomic risk factors in 3 types of open surgery , laparoscopy , and microsurgery . 
 results : the results revealed that the prevalence of musculoskeletal symptoms of the neck , back , shoulder , and arm is high in surgeons ( over 75% ) . 
 the mean final score of wera was 40.11 , representing the high risk of the 3 types of surgery for the prevalence of musculoskeletal symptoms . 
 results revealed that the prevalence of musculoskeletal symptoms in the neck , waist and wrists had a significant relationship with the body posture in the 3 types of open surgery , laparoscopy , and microsurgery ( p<0.05 ) . 
 conclusion : in the present study , the prevalence of musculoskeletal symptoms was high in the neck , waist , and hands surgeries . 
 depending on the type of surgery , teaching correct working methods , using proper seats and ergonomic equipment are the best strategies to reduce musculoskeletal symptoms in the surgical profession .