Interrelations of risk factors and low back pain in scaffolders.

OBJECTIVES To assess with a cross sectional study the interrelations between physical, psychosocial, and individual risk factors and different end points of low back pain. METHODS In total, 229 scaffolders and 59 supervisors completed a questionnaire about manual handling of materials, awkward back posture, strenuous arm position, perceived exertion, psychosocial load, need for recovery, and general health. Physical load at the worksite was also measured with many frequent observations. Interrelations between risk factors and their relation with four end points of low back pain were investigated. RESULTS Interrelations were strong among self reported determinants of physical load but showed an inverted trend for both age and total working experience, which could indicate the presence of a healthy worker effect. Weak relations existed between variables of psychosocial and physical load. The multivariate analyses showed a significant relation between high manual handling of materials, moderate perceived general health, high job demands, and low back pain in the past 12 months. Chronic low back pain was significantly correlated with high perceived exertion and moderate perceived general health. Severe low back pain was significantly correlated with awkward back postures, high need for recovery, and high job demands. Finally, low back pain with perceived disability was significantly related to strenuous shoulder positions and moderate perceived general health. All end points of low back pain were consistently associated with physical load whereas psychosocial aspects showed a more diverse pattern. CONCLUSIONS The findings of this study suggest that work related risk factors may vary according to different definitions of low back pain. Distinct patterns of risk factors might enhance different expressions of it. Scaffolders are a group at high risk of developing persistent forms of low back pain.