London, Feb 1 : A new systematic review determined that training showing the correct way to lift heavy objects does not necessarily prevent back injuries.
In order to avoid back pain, workers are given proper training on how to handle loads correctly and this generally includes advise on specific lifting techniques.
However this study, which reviewed all the evidence presently available, found no evidence that the advice has any effect.
Researchers examined a total of 11 studies for the review. Eight of the studies dealt with health workers who manually handled patients and three studies addressed baggage handlers and postal workers.
The study participants worked in jobs where back strain was prevalent and where training interventions could alleviate strain. None of the workers were actively seeking treatment for back pain.
Researchers studied one group that received training and one group that did not, but found no difference in reported back pain. Training compared to minor advice (a video) showed no effect on back pain after a year.
In another trial, the researchers found no significant difference in back pain between one group that received training and another group of workers who were provided with back belts. Training and physical exercise were also compared in a trial and again, no difference in back pain was found during a follow-up less than a year later.
Finally, a group receiving both training and assistive devices was compared to a group given training only and a control group that received nothing. A follow-up revealed no difference in back pain.
The researchers said either advocated techniques do not actually reduce the risk of back injury, or workers do not significantly change their habits enough to make any difference.
They concluded that a better understanding of the relationship between work-related back stress exposure and the subsequent development of back pain is needed in order to develop new, innovative ways to prevent back pain caused by lifting.
In an accompanying editorial, Associate Professor Niels Wedderkopp said that the common advice for people with back pain to stay as physically active as possible might not be appropriate for workers who perform heavy lifting.
"A change of job and (prudently) staying active in daily life may be the best way for these patients to regain command of their back and their occupation," BMJ quoted him, as saying.
The review is published on bmj.com.