Low back pain (LBP) affects a large proportion of the population and is an increasingly costly problem in the western world. This review highlights some of the recent theories relating to LBP and the conflicting evidence which has been brought to light. Theories relating to the causes of LBP have included single and multiple factors such as abnormal physical findings, mechanical, psychosocial and economic factors. The two lowest lumbar segments are most often afflicted in LBP sufferers, but the diagnosis of LBP is otherwise uncertain in most cases due to insufficient knowledge relating to the validity of clinical tests, inconsistent terminology and unclear symptomatic patterns. Despite a lack of understanding of the exact anatomical cause of LBP, an abundance of therapeutic models exist, most of which are purely empirical, and few methods have been shown to be clinically useful. Similarly, insufficient knowledge of the causes of LBP makes primary, secondary and tertiary prevention difficult.