The fear of back pain could increase the risk of contracting it according ot a study published in Bio-Med Central. The study involved 5696 newly qualified health care workers
The study suggests that, for those with previous Lower Back Pain (LBP), physical work load has an importance, but not among those without previous LBP. In relation to fear-avoidance beliefs, there is a positive relation between it and LBP of than 30 days in both groups, i.e. those without and with previous LBP. No moderating effect of fear-avoidance beliefs on the association between physical work load and LBP was found among cases with and without LBP.
http://www.biomedcentral.com/content/pdf/1471-2474-10-117.pdf
Another site worth a browse.