***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background The to date evidence for a dose-response relationship between physical workload and the development of lumbar disc diseases is limited . We therefore investigated the possible etiologic relevance of cumulative occupational lumbar load to lumbar disc diseases in a multi-center case-control study . Methods In four study regions in Germany ( Frankfurt/Main , Freiburg , Halle/Saale , Regensburg ) , patients seeking medical care for pain associated with clinical ly and radiologically verified lumbar disc herniation ( 286 males , 278 females ) or symptomatic lumbar disc narrowing ( 145 males , 206 females ) were prospect ively recruited . Population control subjects ( 453 males and 448 females ) were drawn from the regional population registers . Cases and control subjects were between 25 and 70 years of age . In a structured personal interview , a complete occupational history was elicited to identify subjects with certain minimum workloads . On the basis of job task-specific supplementary surveys performed by technical experts , the situational lumbar load represented by the compressive force at the lumbosacral disc was determined via biomechanical model calculations for any working situation with object h and ling and load-intensive postures during the total working life . For this analysis , all manual h and ling of objects of about 5 kilograms or more and postures with trunk inclination of 20 degrees or more are included in the calculation of cumulative lumbar load . Confounder selection was based on biologic plausibility and on the change-in-estimate criterion . Odds ratios ( OR ) and 95 % confidence intervals ( CI ) were calculated separately for men and women using unconditional logistic regression analysis , adjusted for age , region , and unemployment as major life event ( in males ) or psychosocial strain at work ( in females ) , respectively . To further eluci date the contribution of past physical workload to the development of lumbar disc diseases , we performed lag-time analyses . Results We found a positive dose-response relationship between cumulative occupational lumbar load and lumbar disc herniation as well as lumbar disc narrowing  among men and women . Even past lumbar load seems to contribute to the risk of lumbar disc disease . Conclusion According to our study , cumulative physical workload is related to lumbar disc diseases among men and women OBJECTIVES To investigate the relation with a case-control study between symptomatic osteochondrosis or spondylosis of the lumbar spine and cumulative occupational exposure to lifting or carrying and to working postures with extreme forward bending . METHODS From two practice s and four clinics were recruited 229 male patients with radiographically confirmed osteochondrosis or spondylosis of the lumbar spine associated with chronic complaints . Of these 135 had additionally had acute lumbar disc herniation . A total of 197 control subjects was recruited : 107 subjects with anamnestic exclusion of lumbar spine disease were drawn as a r and om population control group and 90 patients admitted to hospital for urolithiasis who had no osteochondrosis or spondylosis of the lumbar spine radiographically were recruited as a hospital based control group . Data were gathered in a structured personal interview and analysed using logistic regression to control for age , region , nationality , and other diseases affecting the lumbar spine . To calculate cumulative forces to the lumbar spine over the entire working life , the Mainz-Dortmund dose model ( MDD ) , which is based on an overproportional weighting of the lumbar disc compression force relative to the respective duration of the lifting process was applied with modifications : any objects weighing ⩾5 kg were included in the calculation and no minimum daily exposure limits were established . Calculation of forces to the lumbar spine was based on self reported estimates of occupational lifting , trunk flexion , and duration . RESULTS For a lumbar spine dose > 9 × 106 Nh ( Newton × hours ) , the risk of having radiographically confirmed osteochondrosis or spondylosis of the lumbar spine as measured by the odds ratio ( OR ) was 8.5 ( 95 % confidence interval ( 95 % CI ) 4.1 to 17.5 ) compared with subjects with a load of 0 Nh . To avoid differential bias , forces to the lumbar spine were also calculated on the basis of an internal job exposure matrix based on the control subjects ' exposure assessment s for their respective job groups . Although ORs were lower with this approach , they remained significant . CONCLUSIONS The calculation of the sum of forces to the lumbar spine is a useful tool for risk assessment for symptomatic osteochondrosis or spondylosis of the lumbar spine . The results suggest that cumulative occupational exposure to lifting or carrying and extreme forward bending increases the risk for developing symptomatic osteochondrosis or spondylosis of the lumbar spine OBJECTIVE To explore the risk factors of lumbar intervertebral disc herniation in the 5 northern provinces of China . METHODS A total of 2010 patients with established diagnosis of lumbar disc herniation by CT and /or MRI and 2170 control subjects without a history of low back pain or sciatica were r and omly selected from the community population and hospitalized patients . The family history of lumbar disc herniation , occupations , smoking status , and occupational psychosocial factors  were investigated . RESULTS The positivity of family history of lumbar disc herniation was the highest risk factor ( OR=3.551 ) followed by lumbar load ( OR=2.132 ) and hard work ( OR=1.763 ) .  Physical exercises  ( OR=0.435 ) were significantly related with the disease , and the OR of the type of bed was 0.364 . CONCLUSION A family history of lumbar disc herniation , lumbar load and hard work are the major risk factors for lumbar disc herniation , and physical exercises and sleeping not in soft bed might be a protective factor against the disease BACKGROUND CONTEXT A range of morphologic and psychosocial variables has been suggested as risk factors for serious low back pain ( LBP ) illness . Although the relative contributions of structural and psychosocial variables are intensely debated , the validity of differing hypotheses has proven difficult to test because the incidence of serious disabling LBP illness is low in healthy subjects . These factors dictate the requirement for large sample sizes , extensive structural imaging and extended longitudinal study . Previous studies included either small cohorts with intensive imaging testing or large population studies that do not establish a detailed morphologic baseline . PURPOSE To establish , using a strict patient sample design , the relative contribution of structural and psychosocial determinants of serious LBP illness among subjects with no previous LBP disability or clinical LBP illness . STUDY DESIGN / SETTING A prospect i ve , longitudinal study of subjects with high risk factors for serious LBP as determined by structural and psychosocial characteristics . PATIENT SAMPLE One hundred subjects with known mild persistent low back pain and a 2:1 ratio of chronic ( non-lumbar ) pain syndrome were recruited from a study population with a predisposition to disc degenerative disease , to undergo baseline examination , testing and 5-year follow-up . OUTCOME MEASURES Observations were made at 6-month intervals over 4 to 6 years ( mean , 5.3 ) for the after primary outcomes measures : episodes of serious back pain ( visual analogue scale [ VAS ] > or = 6 ) , episodes of occupational disability less than 1 week , episodes of occupational disability for 1 week , remission episodes of all back pain symptoms at least 6 months and medical visits primarily for LBP evaluation and treatment . METHODS Lumbar magnetic resonance imaging ( MRI ) , lumbar provocative discography ( in psychometrically normal subjects ) , physical examinations , medical and work histories and psychometric testing were performed at baseline . Imaging and psychometric testing were grade d by blinded examiners . A scripted interview was conducted every 6 months during follow-up by independent research assistants who also were blinded to patient baseline data . The interview covered interval medical , occupational and accident or injury histories . RESULTS Psychosocial variables strongly predicted both long- and short-term disability events , duration and health-care visits for LBP problems ( p<0.0001 - 0.004 ) . The likelihood of a sustained remission from the baseline persistent ( sub clinical ) LBP appeared to be linked to occupation factors ( leaving a heavy labor occupation ; p=0.0001 ) , neurophysiologic variables ( chronic nonlumbar pain ; p=0.0002 ) and psychometric profiles at baseline ( DRAM and FABQ-PA ; p=0.003 - 0.002 ) . Of the structural findings measured only moderate or severe Modic changes of the vertebral end plate were weakly associated with an adverse outcome . A positive provocative discogram at baseline did not predict any future adverse event . CONCLUSION The development of serious LBP disability in a cohort of subjects with both structural and psychosocial risk factors was strongly predicted by baseline psychosocial variables . Structural variables on both MRI and discography testing at baseline had only weak association with back pain episodes and no association with disability or future medical care A total 71 male athletes ( weight lifters , wrestlers , orienteers , and ice-hockey players ) and 21 non-athletes were r and omly selected , for a baseline MRI study . After 15 years all the participants at baseline were invited to take part in a follow-up examination , including a question naire on back pain and a follow-up MRI examination .  Thirty-two athletes and all non-athletes had disc height reduction at one or several disc levels . Disc degeneration was found in more than 90 % of the athletes and deterioration had occurred in 88 % of the athletes , with the highest frequency in weight lifters and ice-hockey players . 78 % of the athletes and 38 % of the non-athletes reported previous or present history of back pain at baseline and 71 and 75 % , respectively at follow-up . There was no statistically significant correlation between back pain and MRI changes . In conclusion , athletes in sports with severe or moderate dem and s on the back run a high risk of developing disc degeneration and other abnormalities of the spine on MRI and they report high frequency of back pain . The study confirmed our hypothesis , i.e. that most of the spinal abnormalities in athletes seem to occur during the growth spurt , since the majority of the abnormalities demonstrated at follow-up MRI after the sports career were present already at baseline . The abnormalities found at young age deteriorated to a varying degree during the 15-year follow-up , probably due to a combination of continued high load sporting activities and normal ageing . Preventive measures should be considered to avoid the development of these injuries in young athletes An increased frequency of radiologic abnormalities in the thoracolumbar spine has been reported among young athletes in various sports , but there are no data concerning ski sports . To evaluate the incidence of these abnormalities in young elite skiers , we compared 120 skiers younger than 17 years old ( alpine skiers , ski jumpers , and Nordic cross-country skiers ) with a r and om sample of 39 control subjects of the same age who had no history of high-performance sports participation . St and ardized anteroposterior and lateral radiographs of the entire lumbar spine , the lower thoracic spine , and the upper part of the sacrum were obtained from each athlete and each control subject . Radiographs were evaluated by two independent observers for the presence and size of anterior and posterior endplate lesions and Schmorl 's nodes . The elite alpine skiers and ski jumpers demonstrated a significantly higher rate of anterior endplate lesions than did the control subjects . This finding might be attributable to excessive loading and repetitive trauma of the immature spine under high velocity , especially in the forward bent posture 965 workers engaged in working tasks of work intensity grade 2 , 3 , 4 ( based on Chinese National St and ard ) were investigated on the musculoskeletal disorders with a question naire . The lumbar vertebra of 136 r and omly chosen workers were also radiologically examined . The result revealed that the prevalence of low-back disorders was 51.2 % on average and it was obviously correlated with such factors as age , st and ing , previous back injury , education level , sport activity , work intensity , working posture , satisfaction with the tools as well as work condition and house work . Heavy work load and unneutral working posture were proved to be the main factors as revealed by the multifactor analysis and further supported by the findings of X-ray examination OBJECTIVE To investigate the epidemiological features of back pain , spondyloarthritis ( SpA ) and ankylosing spondylitis ( AS ) in Beijing Shougang district . METHODS Set up Chinese version of question naire about incidence of spondyloarthropathy . Employees and retired ones were drawn out from sub-factory units by non-r and omized sampling.15 357 subjects were investigated , of which 12 125 question naires were taken . Suspected cases were then screened with sacroiliac joint X ray and HLA-B(27 ) testing . 2009 assessment in ankylosing spondylitis ( ASAS ) criteria were used for diagnosing SpA. RESULTS Back pain is common with total incidence of 42.7 % , and the most common pattern is mechanical pain . The incidence of SpA is 0.58 % and that of AS is 0.36 % , while only 28.9 % AS patients had been diagnosed before and received treatment . CONCLUSION The AS incidence in Shougang district is similar with the epidemiological data got from other districts of China . And knowledge of SpA and AS is needed in China Study Design Prospect i ve cohort study . Purpose To determine whether there was any change in the quality of life of patients in sedentary/non sedentary occupations treated with epidural steroid injection for lumbar disc herniations using the 8 components of the SF 36 question naire . Overview of Literature : No previously done similar study published . Overview of Literature No previously done similar study published . Methods Ninety patients comprising sedentary and 
    Output:
    
Conclusions There was moderate evidence suggesting a modest association between occupational loading and disc degeneration ( signal intensity ) , and low- quality evidence of an association between occupational loading and disc narrowing and bulging