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 .
How study design affects outcomes in comparisons of therapy. I: Medical.
We analysed 113 reports published in 1980 in a sample of medical journals to relate features of study design to the magnitude of gains attributed to new therapies over old . Overall we rated 87 per cent of new therapies as improvements over st and ard therapies . The mean gain ( measured by the Mann-Whitney statistic ) was relatively constant across study design s , except for non-r and omized controlled trials with sequential assignment to therapy , which showed a significantly higher likelihood that a patient would do better on the innovation than on st and ard therapy ( p = 0.004 ) . R and omized controlled trials that did not use a double-blind design had a higher likelihood of showing a gain for the innovation than did double-blind trials ( p = 0.02 ) . Any evaluation of an innovation may include both bias and the true efficacy of the new therapy , therefore we may consider making adjustments for the average bias associated with a study design . When interpreting an evaluation of a new therapy , readers should consider the impact of the following average adjustments to the Mann-Whitney statistic : for trials with non-r and om sequential assignment a decrease of 0.15 , for non-double-blind r and omized controlled trials a decrease of 0.11
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 .