title: Work factors as predictors of intense or disabling low back pain; a prospective study of nurses’ aides Assessment of psychosocial risk factors for the development of non-specific chronic disabling low back pain in Japanese workers—findings from the Japan Epidemiological Research of Occupation-related Back Pain (JOB) study Prevalence of work-related musculoskeletal symptoms of the neck and upper extremity among dentists in China Potential Risk Factors of Persistent Low Back Pain Developing from Mild Low Back Pain in Urban Japanese Workers Assessment of dental student posture in two seating conditions using RULA methodology – a pilot study GRADE guidelines: 3. Rating the quality of evidence. A dental stool with chest support reduces lower back muscle activation Differences in erect sitting and natural sitting spinal alignment-insights into a new paradigm and implications in deformity correction.
abstract: Aims : To identify the work factors that predict  intense low back pain ( LBP ) and LBP related sick leaves in nurses ’ aides . Methods : The sample comprised 4266 r and omly selected Norwegian nurses ’ aides , not bothered or only a little bothered by LBP during the previous three months , and not on sick leave when completing a mailed question naire in 1999 . Of these , 3808 ( 89.3 % ) completed a second question naire 3 months later and 3651 ( 85.6 % ) completed a third question naire 15 months later . Intensity of low back symptoms and certified sick leaves attributed to LBP during the observation period were assessed by self reports at the follow ups . Results : After adjustments for LBP during the three months prior to baseline , baseline health complaints , demographic and familial factors , and a series of physical , psychological , and social work factors , logistic regression analyses revealed the following associations : intense low back symptoms were predicted by frequent positioning of patients in bed , perceived lack of support from immediate superior , and perceived lack of pleasant and relaxing culture in the work unit . LBP related sick leaves were predicted by frequent h and ling of heavy objects , medium level of work dem and s , perceived lack of supportive and encouraging culture in the work unit , working night shifts , and working in a nursing home . Long term LBP related sick leaves were associated with changes of work or work tasks during the observation period that result ed in a perceived reduction of support and encouragement at work . Conclusions : Not only frequent mechanical exposures , but also organisational , psychological , and social work factors , such as night shift work , perceived lack of support from superior , and perceived lack of a pleasant and relaxing or supporting and encouraging culture in the work unit , are associated with an increased risk of intense low back symptoms and LBP related sick leaves in nurses ’ aides To investigate the associations between psychosocial factors and the development of  chronic disabling low back pain ( LBP ) in Japanese workers . A 1 yr prospect i ve cohort of the Japan Epidemiological Research of Occupation-related Back Pain ( JOB ) study was used . The participants were office workers , nurses , sales/marketing personnel , and manufacturing engineers . Self-administered question naires were distributed twice : at baseline and 1 yr after baseline . The outcome of interest was the development of chronic disabling LBP during the 1 yr follow-up period . Incidence was calculated for the participants who experienced disabling LBP during the month prior to baseline . Logistic regression was used to assess risk factors for chronic disabling LBP . Of 5,310 participants responding at baseline ( response rate : 86.5 % ) , 3,811 completed the question naire at follow-up . Among 171 eligible participants who experienced disabling back pain during the month prior to baseline , 29 ( 17.0 % ) developed chronic disabling LBP during the follow-up period . Multivariate logistic regression analysis implied reward to work ( not feeling rewarded , OR : 3.62 , 95%CI : 1.17–11.19 ) , anxiety ( anxious , OR : 2.89 , 95%CI : 0.97–8.57 ) , and daily-life satisfaction ( not satisfied , ORs : 4.14 , 95%CI : 1.18–14.58 ) were significant . Psychosocial factors are key to the development of chronic disabling LBP in Japanese workers .  Psychosocial interventions may reduce the impact of LBP in the workplace Objectives Studies from western countries show that dentists are vulnerable to work-related musculoskeletal disorders ( WMSDs ) of the neck and upper extremities , but little is known about their epidemiology among members of this rapidly growing profession in China . This study aims to investigate the prevalence of WMSDs and identify potential risk factors associated with their occurrence in the dental profession in China . Setting and participants A cross-sectional survey was carried out in 52 different hospitals in a large metropolitan city in China . A total of 304 question naires were distributed to respondents identified via stratified r and om sampling and 272 dentists ( 121 females and 151 males ) completed the survey . The response rate was 89.5 % . Outcomes Visual analogue score was used to record neck and upper limb musculoskeletal symptoms on a body chart . Work-related risk factors , including physical and psychosocial factors , were accounted for in the regression analysis . Results 88 % of the dentists reported at least one musculoskeletal disorder and 83.8 % suffered from neck pain . In the multivariate analyses , working hours per day were associated with neck pain ( OR=1.43 ; 95 % CI 1.03 to 1.98 ) . Inability to select the appropriate size of dental instrument was associated with shoulder ( OR=2.07 ; 95 % CI 1.00 to 4.32 ) and wrist/h and ( OR=2.47 ; 95 % CI 1.15 to 5.32 ) pain . As for psychosocial factors , high job dem and was associated with symptoms in the shoulder ( OR=1.09 ; 95 % CI 1.00 to 1.18 ) , elbow ( OR=1.11 ; 95 % CI 1.03 to 1.19 ) and wrist/h and ( OR=1.09 ; 95 % CI 1.02 to 1.17 ) . Regular physical exercise was associated with decreased neck pain ( OR=0.37 ; 95 % CI 0.14 to 1.00 ) . Conclusions The prevalence of WMSDs among Chinese dentists is high . Specifically , long working hours , inability to select the appropriate size of dental instrument and high job dem and are the most significant risk factors Study Design Two-year , prospect i ve cohort data from the Japan epidemiological research of occupation-related back pain study in urban setting s were used for this analysis . Objective To examine the association between aggravated low back pain and psychosocial factors among Japanese workers with mild low back pain . Summary of Background Data Although psychosocial factors are strongly indicated as yellow flags of low back pain ( LBP ) leading to disability , the association between aggravated LBP and psychosocial factors has not been well assessed in Japanese workers . Methods At baseline , 5,310 participants responded to a self-administered question naire including questions about individual characteristics , ergonomic work dem and s , and work-related psychosocial factors ( response rate : 86.5 % ) , with 3,811 respondents completing the 1-year follow-up question naire . The target outcome was aggravation of mild LBP into persistent LBP during the follow-up period . Incidence was calculated for the participants with mild LBP during the past year at baseline . Logistic regression was used to explore risk factors associated with persistent LBP . Results Of 1,675 participants who had mild LBP during the preceding year , 43 ( 2.6 % ) developed persistent LBP during the follow-up year . Multivariate analyses adjusted for individual factors and an ergonomic factor found statistically significant or almost significant associations of the following psychosocial factors with persistent LBP : interpersonal stress at work [ adjusted odds ratio ( OR ) : 1.96 and 95 % confidence interval ( 95%CI ) : 1.00–3.82 ] , job satisfaction ( OR : 2.34 , 95%CI : 1.21–4.54 ) , depression ( OR : 1.92 , 95%CI : 1.00–3.69 ) , somatic symptoms ( OR : 2.78 , 95%CI : 1.44–5.40 ) , support from supervisors ( OR : 2.01 , 95%CI : 1.05–3.85 ) , previous sick-leave due to LBP ( OR : 1.94 , 95%CI : 0.98–3.86 ) and family history of LBP with disability ( OR : 1.98 , 95%CI : 1.04–3.78 ) . Conclusions Psychosocial factors are important risk factors for persistent LBP in urban Japanese workers . It may be necessary to take psychosocial factors into account , along with physical work dem and s , to reduce LBP related disability 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 This article introduces the approach of GRADE to rating  quality of evidence .  GRADE specifies four categories-high , moderate , low , and very low-that are applied to a body of evidence , not to individual studies . In the context of a systematic review , quality reflects our confidence that the estimates of the effect are correct . In the context of recommendations , quality reflects our confidence that the effect estimates are adequate to support a particular recommendation . R and omized trials begin as high- quality evidence , observational studies as low quality . " Quality " as used in GRADE means more than risk of bias and so may also be compromised by imprecision , inconsistency , indirectness of study results , and publication bias . In addition , several factors can increase our confidence in an estimate of effect . GRADE provides a systematic approach for considering and reporting each of these factors . GRADE separates the process of assessing quality of evidence from the process of making recommendations . Judgments about the strength of a recommendation depend on more than just the quality of evidence Activation of back musculature during work tasks leads to fatigue and potential injury . This is especially prevalent in dentists who perform much of their work from a seated position . We examined the use of an ergonomic dental stool with mid-sternum chest support for reducing lower back muscle activation . Electromyography of lower back extensors was assessed from 30 dental students for 20 s during three conditions in r and om order : ( a ) sitting upright at 90 ° of hip flexion on a st and ard stool , ( b ) leaning forward at 80 ° of hip flexion on a st and ard stool , and ( c ) leaning forward at 80 ° of hip flexion while sitting on an ergonomic stool . Muscular activity of the back extensors was reduced when using the ergonomic stool compared to the st and ard stool , by 33–50 % ( p < 0.01 ) . This suggests a potential musculoskeletal benefit with use of a dental stool with mid-sternum chest support BACKGROUND CONTEXT Sitting spinal alignment is increasingly recognized as a factor influencing strategy for deformity correction . Considering that most individuals sit for longer hours in a " slumped " rather than in an erect posture , greater underst and ing of the natural sitting posture is warranted . PURPOSE This study aim ed to investigate the differences in sagittal spinal alignment between two common sitting postures : a natural , patient-preferred posture ; and an erect , investigator-controlled posture that is commonly used in alignment studies . DESIGN / SETTING This is a r and omized , prospect i ve study of 28 young , healthy patients seen in a tertiary hospital over a 6-month period . PATIENT SAMPLE Twenty-eight patients ( 24 men , 4 women ) , with a mean age of 24 years ( range 19 - 38 ) , were recruited for this study . All patients with first episode of lower back pain of less than 3 months ' duration were included . The exclusion criteria consisted of previous spinal surgery , radicular symptoms , red flag symptoms , previous spinal trauma , obvious spinal deformity on forward bending test , significant personal or family history of malignancy , and current pregnancy . OUTCOME MEASURES Radiographic measurements included sagittal vertical axis ( SVA ) , lumbar lordosis ( LL ) , thoracolumbar angle ( TL ) , thoracic kyphosis ( TK ) , and cervical lordosis ( CL ) . St and ard spinopelvic parameters ( pelvic incidence , pelvic tilt [ PT ] , and sacral slope ) and sagittal apex and end vertebrae were also measured . METHODS Basic patient demographics ( age , gender , ethnicity ) were recorded . Lateral sitting whole spine radiographs were obtained using a slot scanner in the imposed erect and the natural sitting posture . Statistical analyses of the radiographical parameters were performed comparing the two sitting postures using chi-squared tests for categorical variables and paired t tests for continuous variables . RESULTS There was forward SVA shift between the two sitting postures by a mean of 2.9 cm ( p<.001 ) . There was a significant increase in CL by a mean of 11.62 ° ( p<.001 ) , and TL kyphosis by a mean of 11.48 ° ( p<.001 ) , as well as a loss of LL by a mean of 21.26 ° ( p<.001 ) . The mean PT increased by 17.68 ° ( p<.001 ) . The entire thoracic and lumbar spine has the tendency to form a single C-shaped curve with the apex moving to L1 ( p=.002 ) vertebra in the majority of patients . CONCLUSIONS In a natural sitting posture , the lumbar spine becomes kyphotic and contributes to a single C-shaped sagittal profile comprising the thoracic and the lumbar spine . This is associated with an increase in CL and PT , as well as a constant SVA . These findings lend insight into the body 's natural way of energy conservation using the posterior ligamentous tension b and while achieving sitting spinal sagittal balance . It also provides information on one of the possible causes of proximal junctional kyphosis or proximal junctional failure
target: The two eligible studies for this review provide moderate evidence that saddle seats provided lower ergonomic risk than conventional seats in the examined population of dental students
background: OBJECTIVE This study aim ed to verify whether the saddle seat provides lower ergonomic risk than conventional seats in dentistry .