Risk factors for low back pain: insights from a novel case-control twin study

Background contextPrevious research has failed to identify strong consistent risk factors for low back pain (LBP). A plausible solution is to conduct hypothesis-generating studies, such as twin case-control surveys.PurposeTo investigate twins' perceptions of the factors responsible for within-pair differences in LBP.Study designA case-control twin survey.Patient sampleTwenty-four twin pairs that were generally and broadly discordant for LBP history.Outcome measuresThe participants' perceptions of the factors that could explain within-pair differences in LBP history.MethodsTwins were asked to identify the factors responsible for within-pair differences in LBP. Closed questioning collected information on the known risk factors and open-ended questioning was used to reveal novel factors. The frequency of risk factors was presented to investigate the individual's perception of the contribution of factors in the development of their own and/or their twin's experience of LBP.ResultsThe most frequent factors reported in the closed questioning related to the physical workload of the lumbar spine, specifically, the engagement in different types of work (n=23/24 pairs, 96%). Types of work included those involving heavy loads, lifting, manual tasks, awkward postures, and gardening. Single trauma or injury and vigorous physical activity participation were perceived as the contributors by 79% (n=19/24 pairs) and 88% (n=21/24 pairs) of the pairs, respectively. Open-ended questioning did not reveal new risk factors for LBP.ConclusionsTwins attributed the differences in LBP history to risk factors related to physical workload. Future studies investigating the risk factors for LBP should include valid and comprehensive assessments of these factors.