The trials suggest that work place exercise is effective , braces and education are ineffective , and workplace modification plus education is of unknown value in preventing low back pain
A systematic review of r and omised controlled trials was undertaken to evaluate the effectiveness of  workplace interventions  to prevent low back pain .
Randomized versus historical controls for clinical trials.
To compare the use of  r and omized controls ( RCTs ) and historical controls ( HCTs )  for clinical trials , we search ed the literature for therapies studied by both methods . We found six therapies for which 50 RCTs and 56 HCTs were reported . Forty-four of 56 HCTs  ( 79 percent ) found the therapy better than the control regimen , but only 10 of 50 RCTs ( 20 percent ) agreed . For each therapy , the treated patients in RCTs and HCTs of the same therapy was largely due to differences in outcome for the control groups , with HCT control patients generally doing worse than the RCT control groups . Adjustment of the outcomes of the HCTs for prognostic factors , when possible , did not appreciably change the results . The data suggest that biases in patient selection may irretrievably weight the outcome of HCts in favor of new therapies . RCTs may miss clinical ly important benefits because of inadequate attention to sample size . The predictive value of each might be improved by reconsidering the use of p less than 0.05 as the significance level for all types of clinical trials , and by the use of confidence intervals around estimates of treatment effects
The trials suggest that work place exercise is effective , braces and education are ineffective , and workplace modification plus education is of unknown value in preventing low back pain
A systematic review of r and omised controlled trials was undertaken to evaluate the effectiveness of  workplace interventions  to prevent low back pain .