Working postures of dentists and dental hygienists. Evaluation of ergonomic factors and postures that cause muscle pains in dentistry students’ bodies Effect of magnification lenses on student operator posture. Effect of magnification loupes on dental hygiene student posture. Reducing musculoskeletal disorders among computer operators: comparison between ergonomics interventions at the workplace The burden and determinants of neck pain in workers: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Ergonomic intervention: its effect on working posture and musculoskeletal symptoms in female biomedical scientists. Musculoskeletal disorders and occupational exposures: How should we judge the evidence concerning the causal association? Assessment of dental student posture in two seating conditions using RULA methodology – a pilot study The Effect of an Ergonomic Intervention on Musculoskeletal, Psychosocial and Visual Strain of VDT Data Entry Work: The United States Part of the International Study
A joint study was conducted by a manufacturer of dental stools in the Midwest of the United States and Marquette University to measure the occupational postures of dentists and dental hygienists . The postures of 10 dentists and 10 dental hygienists were assessed using work sampling and video techniques .  Postural data of the neck , shoulders and lower back were recorded from video and categorized into 30-degree intervals : o ( neutral posture of respective joint ) , 30 , 60 and 90 degrees . Each subject 's postures were observed while they were treating patients during a four-hour period , during which 100 observations of postures were recorded at r and om times . Compared to st and ing , dentists and dental hygienists were seated 78 percent and 66 percent of the time , respectively . Dentists and dental hygienists flexed their trunk at least 30 degrees more than 50 percent of the time . They flexed their neck at least 30 degrees 85 percent of the time during the four-hour duration , and their shoulders were elevated to the side of their trunk ( abducted ) at least 30 degrees more half of the time . The postures of the trunk , shoulders , and neck were primarily static . This data base of postures can be used by dental professionals and ergonomists to assess the risk dentists and dental hygienists are exposed to musculoskeletal disorders , such as low back pain or shoulder tenosynovitis , from deviated joint postures . They could use these data to select dental furniture or dental devices that promote good body posture , i.e. , reduce the magnitude and duration of deviated joint postures , which , in theory , would decrease the risk of musculoskeletal disorders Background Work-related musculoskeletal disorders commonly experienced by dental professionals are one of the main occupational health problem affecting their health and well-being . This study was conducted to evaluate  ergonomic factors and profession-related postures  and also investigate relationship between demographic factors and work condition with pain in dental students . Material and Methods 60 freshman and sophomore dentistry students were r and omly chosen as the subjects of control group , and 60 of 5th and 6th-year students were selected as the members of exposure group . Data related to the subjects such as sex , doing exercise , severity of musculoskeletal pain were obtained through question naire . Students ’ postures were directly observed while treating patients and they were scored by REBA method . Data were analyzed by SPSS software using Man-Whitney , Kruskal-Wallis , Spearman and Kendall correlation tests . Results 80.8 % of the subjects were not aware of the correct ergonomic postures for dental procedures . Severity of musculoskeletal pain in the exposure group ( 15.9± 4.2 ) was significantly higher than the control group ( 10.5 ±3.2 ) , ( p < 0.001 ) . Risk of the most subjects ( 84 % ) was at the medium level . Students who were more involved in clinical activities experienced more muscular pains . Conclusions The musculoskeletal disorders are probable prolonged in working hours in static positions , incorrect work postures , implying more force and even tools and instruments . Therefore , students who are aware of ergonomic principals of their own profession would be able to maintain their health through activities and lifelong . Key words : Posture , dentistry , students , musculoskeletal pain A distinct body of literature supports the association between clinical postures of the dental practitioner and work-related musculoskeletal disorders ( WRMD ) . Several aids or devices have been tested to improve clinical posture in the interest of decreasing WRMD . The use of magnification lenses while performing dental procedures may increase the quality of work and decrease the likelihood of musculoskeletal problems . To date , only anecdotal and personal opinions had existed regarding the benefits of using magnification lenses , and no empirical evidence had authenticated the contention that use of magnification lenses exerts a positive change in operator posture . The objective of this study was to assess the effect magnification lenses had on the posture of dental hygiene students . Using a r and omized crossover design , research ers videotaped nineteen senior dental hygiene students performing an intra-oral procedure with and without the use of magnification lenses . The tapes were then evaluated by a panel of five dental hygiene educators calibrated in the use of Branson 's Posture Assessment Instrument ( PAI ) . Results of a paired t-test indicate that the posture of the students while wearing magnification lenses was more acceptable ( p=.019 ) than when wearing traditional safety glasses . Results of this study indicate a quantifiable change in acceptability of posture for clinicians wearing magnification lenses  and suggest that the use of such lenses in dental education may be warranted The chair-side work posture of dental hygienists has long been a concern because of health-related problems potentially caused or exacerbated by poor posture . The purpose of this study was to investigate if using magnification loupes improved dental hygiene students ' posture during provision of treatment . The treatment chosen was h and -scaling , and the effect of the timing of introduction of the loupes to students was also examined . Thirty-five novice dental hygiene students took part in the study . Each student was assessed providing dental hygiene care with and without loupes , thus controlling for innate differences in natural posture . Students were r and omized into two groups . Group one used loupes in the first session and did not use them for the second session . Group two reversed this sequence . At the end of each session , all students were videotaped while performing scaling procedures . Their posture was assessed using an adapted version of Branson et al. 's Posture Assessment Instrument ( PAI ) . Four raters assessed students at three time periods for nine posture components on the PAI . A paired t-test compared scores with and without loupes for each student . Scores showed a significant improvement in posture when using loupes ( p<0.0001 ) , and these improvements were significantly more pronounced for students starting loupes immediately on entering the program compared with students who delayed until the second session ( p<0.1 ) . These results suggest a significant postural benefit is realized by requiring students to master the use of magnification loupes as early as possible within the curriculum Typing is associated with musculoskeletal disorders ( MSDs ) caused by multiple risk factors . This control study aim ed to evaluate the efficacy of a workplace intervention for reducing  MSDs among computer workers . Sixty-six subjects with and without MSD were assigned consecutively to one of three groups : ergonomics intervention ( work site and body posture adjustments , muscle activity training and exercises ) accompanied with biofeedback training , the same ergonomics intervention without biofeedback and a control group . Evaluation of MSDs , body posture , psychosocial status , upper extremity ( UE ) kinematics and muscle surface electromyography were carried out before and after the intervention in the workplace and the motion lab . Our main hypothesis that significant differences in the reduction of MSDs will exist between subjects in the study groups and controls was confirmed ( χ2 = 13.3 ; p = 0.001 ) . Significant changes were found in UE kinematics and posture as well . Both ergonomics interventions effectively reduced MSD and improved body posture . Practitioner Summary : This study aim ed to test the efficacy of an individual workplace intervention programme among computer workers by evaluating musculoskeletal disorders ( MSDs ) , body posture , upper extremity kinematics , muscle activity and psychosocial factors were tested . The proposed ergonomics interventions effectively reduced MSDs and improved body posture STUDY DESIGN Systematic review and best evidence synthesis . OBJECTIVES To describe the prevalence and incidence of  neck pain and disability in workers ; to identify risk factors for neck pain in workers ; to propose an etiological diagram ; and to make recommendations for future research . SUMMARY OF BACKGROUND DATA Previous review s of the etiology of neck pain in workers relied on cross-sectional evidence . Recently published cohorts and r and omized trials warrant a re- analysis of this body of research . METHODS We systematic ally search ed Medline for literature published from 1980 - 2006 . Retrieved articles were review ed for relevance . Relevant articles were critically appraised . Articles judged to have adequate internal validity were included in our best evidence synthesis . RESULTS One hundred and nine papers on the burden and determinants of neck pain in workers were scientifically admissible . The annual prevalence of neck pain varied from 27.1 % in Norway to 47.8 % in Québec , Canada . Each year , between 11 % and 14.1 % of workers were limited in their activities because of neck pain . Risk factors associated with neck pain in workers include age , previous musculoskeletal pain , high quantitative job dem and s , low social support at work , job insecurity , low physical capacity , poor computer workstation design and work posture , sedentary work position , repetitive work and precision work . We found preliminary evidence that gender , occupation , headaches , emotional problems , smoking , poor job satisfaction , awkward work postures , poor physical work environment , and workers ' ethnicity may be associated with neck pain . There is evidence that interventions aim ed at modifying workstations and worker posture are not effective in reducing the incidence of neck pain in workers . CONCLUSION Neck disorders are a significant source of pain and activity limitations in workers . Most neck pain results from complex relationships between individual and workplace risk factors . No prevention strategies have been shown to reduce the incidence of neck pain in workers This study investigates the effect of ergonomic intervention on working posture and musculoskeletal symptoms in female biomedical scientists . The Nordic musculoskeletal question naire ( NMQ ) , body discomfort chart ( BDC ) and rapid upper-limb assessment ( RULA ) are the tools for assessment . The study was conducted in three phases : pre-intervention , intervention and post-intervention . Pre-intervention , 79 % of subjects reported a three-month prevalence of symptoms , and these were reported more frequently by those working in haematology/transfusion . Analysis by RULA showed that the majority ( 59 % ) of postures had a gr and score of four . A further 24 % had scores of five or six . The highest frequency of poor postures was seen in haematology/transfusion . Intervention comprised physical workplace changes , a seminar , and advice on risk factors . In the post-intervention phase , baseline measurements were repeated . Reporting of three-month prevalence of symptoms had decreased to 54 % , and reports of body discomfort also had decreased . The majority ( 64 % ) had a RULA gr and score of three . No observed postures had scores of five or six . In conclusion , ergonomic intervention result ed in an improvement in working postures , and a decrease in the prevalence of musculoskeletal symptoms and body discomfort . Analysis of findings indicate that RULA scores generally corresponded with reporting of symptoms ( NMQ ) and discomfort ( BDC ) Musculoskeletal disorders ( MSDs ) affecting the back , upper and lower extremities are widespread in the general population , implying a variety of causal factors . Multiple causes are not mutually exclusive , and a high background rate does not preclude associations with specific factors that are uncommon in the general population . MSDs have well-documented associations with occupational ergonomic stressors such as repetitive motion , heavy lifting , non-neutral postures , and vibration . Organizational features of the work environment , such as time pressure and low decision latitude , may also play a role , at least by potentiating the effects of physical loading . Numerous systematic review s have mostly concurred with these overall findings . Nevertheless , some continue to debate whether MSDs are sometimes work-related , even for those performing jobs with repetitive and routinized tasks , heavy lifting , and /or pronounced postural strain . This article discusses ( 1 ) some epidemiologic features of MSDs that underlie that debate ; and ( 2 ) the question of what should appropriately be considered a gold st and ard for scientific evidence on an etiological question such as the health effects of a non-voluntary exposure , such as an occupational or environmental agent . In particular , r and omized clinical trials have little relevance for determining the health effects of non-therapeutic risk factors Objectives To assess dental students ' posture on two different seats in order to determine if one seat predisposes to a difference in working posture . Design A between-subject experimental design was selected . Setting The study was undertaken at the University of Birmingham School of Dentistry in 2006 . Subjects ( material s ) and methods Sixty second year dental students at the University of Birmingham who were attending their fi rst classes in the phantom head laboratory were r and omly selected and allocated to two different seats ( 30 Bambach Saddle Seats and 30 conventional seats ) . Students were trained in the use of the seats . After ten weeks , the students were observed , photographs were taken by the research er and these were assessed using Rapid Upper Limb Assessment ( RULA ) . Main outcome measures The posture of the students was assessed using the RULA . Each student was given a risk score . A Mann Whitney test was used for statistical analysis . Results The results indicated that the students using the conventional seat recorded signifi cantly higher risk scores ( p < 0.05 ) when compared with the students using Bambach Saddle Seat , suggesting an improvement in posture when using the Bambach Saddle Seat . Conclusion RULA has identifi ed that dental students using a Bambach Saddle Seat were able to maintain an acceptable working posture during simulated dental treatment and this seating may reduce the development of work-related musculoskeletal disorders The United States MEPS ( musculoskeletal — eyestrain — psychosocial — stress ) study consisted of 1 group of 28 female data entry operators . The intervention was in 3 parts : workstation re design ( including advanced ergonomic chairs , motorized adjustable workstations , advanced adjustable keyboards , adjustable copyholders , adjustable footrests , monitor support surfaces ) and ergonomic training/coaching and corrective lenses . After the intervention , statistically significant reductions in physical signs ( trigger points , neck and shoulder mobility ) , subjective reports of intensity and frequency of musculoskeletal pain , and subjective reports of visual problems were observed . Static load during the work sample , as assessed by experts , improved after the intervention as did measured postural angles of head and trunk and subjective assessment of users of ergonomic characteristics of the workplaces . For all of these measures , improvements observed 1 month after intervention were also observed in the 1-year follow-up . Trapezius load , as assessed by electromyography ( EMG ) , decreased after intervention , but then increased in the follow-up . The increase was interpreted as a calibration problem
CONCLUSIONS Based on a limited number of studies , the use of ergonomic saddle seats and dental loupes leads to improved working postures .
The use of loupes appears to relieve shoulder , arm and h and pain .
However , their effect on neck pain is scarce .
None of the studies reported on the effect of the saddle seats on musculoskeletal pain .
OBJECTIVES Musculoskeletal disorders affect a high percentage of dentists , dental hygienists and therapists .
Static and awkward working postures are considered as major risk factors .
Proper seat selection and use of magnification loupes are promoted for their ergonomic benefits .
The aim of this review was to evaluate the existing empirical evidence on the effect of the above interventions on ( i ) correction of poor posture and ( ii ) reduction in musculoskeletal pain .