Examining the role of sitting behaviour in non-specific chronic low back pain

Most chronic low back pain (CLBP) lacks a specific diagnosis, leading to it being labelled “non-specific” CLBP (NSCLBP). NSCLBP is a very common and costly musculoskeletal disorder, which is increasingly viewed as a multidimensional disorder, with contributing factors across the biopsychosocial spectrum. Many physical interventions for NSCLBP have demonstrated minimal effectiveness. Targetted management addressing the specific maladaptive physical and psychological behaviours among individuals with NSCLBP has been advocated. One of the most commonly reported aggravating factors for NSCLBP is sitting. However, most existing research on sitting behaviour has been confined to laboratory settings, limiting the ability to analyse, or provide feedback on, sitting behaviour in real-world environments. Recent technological developments have made investigating sitting behaviour outside the laboratory possible. This doctoral thesis examined the role of sitting behaviour in NSCLBP. In particular, this included the validation of a novel wireless posture monitor, investigating perceptions about sitting posture among clinicians and members of the community, and examining the effect of two specific interventions on sitting-related NSCLBP. There are three main parts to this doctoral thesis, comprising seven studies. In the first part (Chapter 2 – three studies), a novel wireless method of analysing lumbo-pelvic posture was demonstrated to have very good reliability and concurrent validity. In the second part (Chapter 3 – two studies), perceptions of what constitutes good seated spinal posture were evaluated among both physiotherapists and members of the community, both with and without NSCLBP. These two studies showed that both physiotherapists and members of the community had a strong preference for lordotic postures of the lumbar spine. There were no significant differences in the perceptions of good sitting posture between those with and without NSCLBP. In the final part (Chapter 4 two studies), the effect of two specific interventions for NSCLBP were examined. In a group of people with mild NSCLBP during sitting, postural biofeedback in isolation significantly reduced their NSCLBP during a 2-hour seated task. However, the magnitude of decrease was small, and there was no follow-up period. The second intervention study demonstrated that a multi-dimensional behavioural-based intervention improved pain and disability among people with more disabling NSCLBP. These improvements were maintained at clinically and statistically significant levels at follow-up three months later, with the improvements primarily related to changes in psychosocial measures rather than physical measures. In conclusion, this doctoral thesis demonstrates that monitoring lumbo-pelvic posture can be done outside laboratory environments. Furthermore, while postural biofeedback may help reduce NSCLBP, physical factors such as sitting behaviour are only one component of the multidimensional problem that is NSCLBP. For more disabling NSCLBP, a multidimensional behavioural-based intervention demonstrates promising results at short-term follow-up.