***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: STUDY DESIGN This study analyzed the effect of lumbar support belts on functional performance . OBJECTIVE To compare lumbar muscle strength and lifting capacity with and without a lumbar belt . SUMMARY OF BACKGROUND DATA Industrialized setting s have begun to encourage the use of lumbar support belts for their employees . It is believed that the belts may decrease the risk of injury and enhance the functional performance of the individual . METHODS Twenty-two subjects ( average age , 27.5 years ) were tested on four separate days to evaluate the effect of a commercially available belt on isolated lumbar isometric strength and functional dynamic lifting capacity .  All subjects had no history of low back problems . The order of testing with and without a belt was r and omized for both conditions . On the first 2 days , subjects performed a seven-angle isometric lumbar extension strength test , 1 day with and 1 day without a lumbar belt . On the following 2 days , subjects were tested to evaluate functional capacity with and without a lumbar belt . The functional capacity evaluation was performed by progressively lifting weighted canisters from various levels . Heart rates were monitored to ensure that a maximum effort was achieved over the different days . RESULTS T tests revealed that isometric lumbar strength and functional lifting capacity was not significantly affected by the belt . CONCLUSION The use of a lumbar belt does not enhance isometric lumbar muscle strength or dynamic lifting capacity CONTEXT Low back pain is a frequent and costly health problem . Prevention of low back pain is important both for the individual patient and from an economic perspective . OBJECTIVE To assess the efficacy of lumbar supports and education in the prevention of low back pain in industry . DESIGN A r and omized controlled trial with a factorial design . SETTING The cargo department of an airline company in the Netherl and s. PARTICIPANTS A total of 312 workers were r and omized , of whom 282 were available for the 6-month follow-up . INTERVENTIONS Subjects were r and omly assigned to 4 groups : ( 1 ) education ( lifting instructions ) and lumbar support , ( 2 ) education , ( 3 ) lumbar support , and ( 4 ) no intervention . Education consisted of 3 group sessions on lifting techniques with a total duration of 5 hours . Lumbar supports were recommended to be used during working hours for 6 months . MAIN OUTCOME MEASURES Low back pain incidence and sick leave because of back pain during the 6-month intervention period . RESULTS Compliance with wearing the lumbar support at least half the time was 43 % . In the 282 subjects for whom data were available , no statistically significant differences in back pain incidence ( 48 [ 36 % ] of 134 with lumbar support vs 51 [ 34 % ] of 148 without , P=.81 ) or in sick leave because of low back pain ( mean , 0.4 days per month with lumbar support vs 0.4 days without , P=.52 ) were found among the intervention groups . In a subgroup of subjects with low back pain at baseline , lumbar supports reduced the number of days with low back pain per month ( median , 1.2 vs 6.5 days per month ; P=.03 ) . CONCLUSIONS Overall , lumbar supports or education did not lead to a reduction in low back pain incidence or sick leave . The results of the subgroup analysis need to be confirmed by future research . Based on our results , the use of education or lumbar supports can not be recommended in the prevention of low back pain in industry Lumbosacral supports ( LSSs ) have been used to minimize the risk of  lower back injuries . Theoretically , an LSS will raise intra-abdominal pressure ( IAP ) and reduce loads in the lower back region . This investigation compared three different LSSs with an unsupported condition . Nine males lifted a weighted box four times , once per condition , at 90 % of their one-repetition maximum . Conditions were compared in terms of effects on IAP and its relieving force on L5-S1 kinetics . A multivariate analysis of covariance revealed no statistically significant differences among the three LSSs and the nonsupport conditions on the aforementioned dependent variables . This suggests that there is no difference among LSSs in terms of their biomechanical effects on the lower back region and that the use of any LSS does not necessarily afford more protection than a proper lift without one The purpose of this study was to examine the effectiveness of weight-belts during the performance of the parallel squat exercise . Six subjects were filmed  ( 40 fps ) as they performed three trials at each of three belt conditions ( NB , none ; LB , light ; HB , heavy ) in r and om order and three load conditions ( 70 , 80 , 90 % 1RM ( one repetition maximum ] in increasing order . The parameters examined were collected and interfaced to a computer via an analog-to-digital ( A/D ) converter : ground reaction forces , intra-abdominal pressure ( IAP ) , and EMG for the rectus abdominus ( RA ) , external oblique ( EO ) , and erector spinae ( ES ) muscles . Most differences were observed during the 90 % 1RM condition , and only they are presented in this paper . Maximum IAP values were always greater ( P less than 0.05 ) for the weight-belt conditions ( LB , 29.2 ; HB , 29.1 greater th an NB , 26,8 kPa ) . Similar results were observed for the mean IAP . The integrated EMG ( iEMG ) activity of the muscles and adjusted mean values for back compressive force and back muscle force followed a similar but opposite pattern , with NB being the greatest . ES mEMG/(L5/S1 ) values for HB ( 18.1 % ) were the least , followed by LB ( 20.01 % ) and NB ( 22.3 % ) . Few differences were observed between belt types . These data suggest that a weight-belt can aid in supporting the trunk by increasing IAP The purpose of this study was to examine the effectiveness of weight-belts during multiple repetitions of the parallel back squat exercise . Five subjects were  filmed ( 50 fps ) as they performed eight consecutive trials at each of two weight-belt conditions [ with belt = WB , without belt = WOB ] in r and om order at their eight-repetition maximum effort . Other parameters examined were ground reaction forces , intra-abdominal pressure ( IAP ) , and mean electromyography ( mEMG ) for the external oblique ( EO ) , erector spinae ( ES ) , vastus lateralis ( VL ) , and bicep femoris ( BF ) muscles . All parameters were collected and interfaced to a computer via an A/D converter . WB repetitions were generally performed faster than WOB repetitions , especially by the later repetitions ( 3.34 vs 3.56 s ) . WB IAP values were consistently greater ( P less than 0.05 ) than WOB values by 25 - 40 % . IAP increased by approximately 11.5 % from the first to the last repetitions . No differences were observed for ES and EO mEMG for belt usage , but values increased by up to 20 % across repetitions . Several differences were observed between WB and WOB for the VL and BF mEMG , with WB values being significantly greater . These data suggest that a weight-belt aids in supporting the trunk by increasing IAP , and that any differential effect due to wearing a weight-belt did not occur over eight repetitions Intra-abdominal pressure ( IAP ) has been widely hypothesized to reduce potentially injurious compressive forces on spinal discs during lifting . To investigate the effects of a st and ard lifting belt on IAP and lifting mechanics , IAP and vertical ground reaction force ( GRF ) were monitored by computer using a catheter transducer and force platform while nine subjects aged 28.2 + /- 6.6 yr dead-lifted  a barbell both with and without a lifting belt at 90 % of maximum . Both IAP and GRF rose sharply from the time force was first exerted on the bar until shortly after it left the floor , after which GRF usually plateaued while IAP either plateaued or declined . IAP rose significantly ( P less than 0.05 ) earlier with than without the belt . When the belt was worn , IAP rose significantly earlier than did GRF . Both with and without the belt , IAP ended its initial surge significantly earlier than did GRF . Variables significantly greater with than without a belt included peak IAP , area under the IAP vs time curve from start of initial IAP surge to lift-off , peak rate of IAP increase after the end of its initial surge , and average IAP from lift-off to life completion . In contrast , average rate of IAP increase during its initial surge was significantly lower with the belt . Correlations are presented which provide additional information about relationships among the variables . Results suggest that the use of a lifting belt increases IAP , which may reduce disc compressive force and improve lifting safety This study was design ed to determine the effect of multimodal intervention and the prevention of back injury , and to evaluate the adverse side effects of using a lumbosacral corset in the workplace . Subjects were 90 male warehouse workers r and omly selected from over 800 employees at a grocery distribution center . Subjects were assigned to three groups : true controls , no back school , no brace orthoses ; back school only ; and back school plus wearing a custom molded lumbosacral orthosis . Comparisons of pre-testing and 6-month follow-up posttesting for abdominal strength , cognitive data , work injury incidence and productivity and use of health care services were evaluated . Controls and training-only group showed no changes in strength productivity or lost time . Orthoses and training-group showed no changes in strength productivity or accident rate ; however , they showed substantially less lost time . This study supports the concept of using education and prophylactic bracing to prevent back injury and reduce time loss . It appears that the use of intermittent prophylactic bracing has no adverse affects on abdominal muscle strength and may contribute to decreased lost time from work injuries Whether or not lifting belts protect workers from injury is a topic of considerable interest in industry . Not only is the protective effect uncertain , but the biomechanical basis for belt function is unclear . The objective of this study was to determine if lifting belts provide a means for controlling trunk motions during asymmetric material -h and ling tasks . We recruited 16 nursing personnel as experienced lifters to participate in two lifting sessions . A lifting belt was worn in one session and for a week prior to this session during the subjects ' routine work activities . Each session required 42 lifts , distributed across three asymmetry conditions ( 0 , 45 , and 90 deg ) and temporally spaced 30 s apart . Foot motion was not permitted in half the lifts . Results indicated that during lifting , lateral bending and twisting motions were reduced by both the lifting belt and foot motion ; the most pronounced effect was observed at 90 deg of asymmetry . Trunk motions in the sagittal plane during lifting were not affected by the lifting belt . These results appear to support the use of lifting belts in asymmetric lifting conditions , but more research is needed to determine whether the muscles in the torso benefit from the reduced motion or are working harder to overcome this resistance to motion , causing increased internal loads on the spine during asymmetric material -h and ling tasks Assessing the quality of r and omized controlled trials ( RCTs ) is important and relatively new . Quality gives us an estimate of the likelihood that the results are a valid estimate of the truth . We present an annotated bibliography of scales and checklists developed to assess quality . Twenty-five scales and nine checklists have been developed to assess quality . The checklists are most useful in providing investigators with guidelines as to what information should be included in reporting RCTs . The scales give readers a quantitative index of the likelihood that the reported methodology and results are free of bias . There are several shortcomings with these scales . Future scale development is likely to be most beneficial if questions common to all trials are assessed , if the scale is easy to use , and if it is developed with sufficient rigor OBJECTIVE --To determine the quality of r and omised controlled trials of exercise therapy for back pain . DESIGN --Computer aided search of published papers and blinded assessment of the methods of studies . SUBJECTS--23 r and omised controlled trials , of which 16 studied exercise therapy given by physiotherapists to individual patients with back pain . Other conservative treatments could be included . MAIN OUTCOME MEASURES --Score for quality of methods ( based on four main categories : study population , interventions , measurement of effect , and data presentation and analysis ) and main conclusion of author(s ) with regard to exercise therapy . RESULTS --Only four studies scored more than 50 points ( maximum 100 ) , indicating that most were of poor quality . Six studies found that exercise was better than reference treatments and 10 reported it to be no better or worse than the reference treatment . Those reporting positive results tended to have higher methods scores ( 4/6 positive v 4/10 negative scored greater than or equal to 42 ) . CONCLUSIONS --No conclusion can be drawn about whether exercise therapy is better than other conservative treatments for back pain or whether a specific type of exercise is more effective . Further trials are needed in which greater attention is paid to methods of study A case-referent study was conducted in an automobile assembly plant to evaluate the health effect of trunk postures , such as bending and twisting , that deviate from anatomically neutral . Cases of back disorders were all those of workers who reported back pain to the medical department in a ten-month period and met the severity criteria of an interview . The referents were r and omly selected workers free of back pain according to medical department records , an interview , and an examination . For each of the final 95 cases and 124 referents , the job was analyzed for postural and lifting requirements with a video recording and software analysis system by analysts blinded to the case/referent status . Back disorders were associated with mild trunk flexion [ odds ratio ( OR ) 4.9 , 95 % confidence interval ( 95 % CI ) 1.4 - 17.4 ] , severe trunk flexion ( OR 5.7 , 95 % CI 1.6 - 20.4 ) , and trunk twist or lateral bend ( OR 5.9 , 95 % CI 1.6 -  
    Output:
    
There is evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending .