Can load carriage system weight, design and placement affect pain and discomfort? A systematic review.

PURPOSE A systematic review of the literature was conducted to answer the following questions: 1. Does usage or weight of load carriage system cause pain, perceived exertion or discomfort? 2. Can load carriage system placement on the spine influence pain, perceived exertion or discomfort? 3. Can load carriage system design influence the amount of pain, perceived exertion or discomfort caused by their use? METHOD Eight databases were searched. Each included study was analysed and quality appraised by two independent reviewers. RESULTS Forty-seven articles that addressed the research questions were included in the study. Significant variability in the study design and populations of the studies prevented data pooling and the evidence is conflicting. However, qualitative synthesis of the studies shows that carrying loads may provoke low back pain; and it may also trigger neck, thoracic and shoulder pain. Backpack weight can influence perceived pain, however other factors are involved. DISCUSSION There is conflicting but positive evidence on the correlation between backpack load carrying and experiencing pain during different stages of life. The research to date is lacking with the most commonly identified methodological deficiencies being poor overall design, the lack of justification of sample size, providing training sessions for examiners, and not utilising calibrated, valid and reliable instruments for measurement.