Since three of four RCTs on lumbar supports reported no effect , there is no evidence for the effectiveness of lumbar supports .
The four RCTs on exercise consistently reported a positive effect , indicating limited evidence for the effectiveness of exercise .
CONCLUSION There is no evidence for the effectiveness of lumbar supports or education in the primary prevention of low back pain at the workplace .
There is limited evidence for the efficacy of exercise , and the effect that can be obtained is moderate .
OBJECTIVE To up date the evidence on the effectiveness of lumbar supports , education and exercise in the primary prevention of low back pain at the workplace .
Effects of an exercise program on sick leave due to back pain.
The purpose s of this study were to evaluate the effect of a weekly exercise program on  short-term sick leave ( less than 50 days ) attributable to back pain and to determine whether changes in absenteeism were related to changes in cardiovascular fitness . Subjects were r and omly assigned to an exercise group ( n = 58 ) and a control group ( n = 53 ) .  Sick leave attributable to back pain was determined in the intervention period of 1 1/2 years and a comparable 1 1/2-year period prior to the study . In the exercise group , the number of episodes of back pain and the number of sick-leave days attributable to back pain in the intervention period decreased by over 50 % . Absenteeism attributable to back pain increased in the control group . The decrease in sick leave in the exercise group was not accompanied by any change in cardiovascular fitness . Suggestions for establishing exercise programs are given
Since three of four RCTs on lumbar supports reported no effect , there is no evidence for the effectiveness of lumbar supports .
The four RCTs on exercise consistently reported a positive effect , indicating limited evidence for the effectiveness of exercise .
CONCLUSION There is no evidence for the effectiveness of lumbar supports or education in the primary prevention of low back pain at the workplace .
There is limited evidence for the efficacy of exercise , and the effect that can be obtained is moderate .
OBJECTIVE To up date the evidence on the effectiveness of lumbar supports , education and exercise in the primary prevention of low back pain at the workplace .