One recent study (O’Keeffe et al. 2

One recent study (O’Keeffe et al. 2013) took into account the existence of distinct movement subgroups among people with LBP, and investigated an ergonomics intervention among those with flexion-related LBP. This study examined a forward-inclined seatpan (‘Back App’) that also features a dynamic component and does not have a backrest, and investigated its effect on sitting discomfort among subjects with flexion-related LBP. Results demonstrated a significant reduction in LBD while sitting on the forward-inclined seatpan when compared to a flat seatpan with a backrest. As the forward-inclined seatpan encourages lumbar lordosis (O’Sullivan et al. 2012b), it was therefore proposed that LBD reduced as a result of the directional nature of the disorder. However, it is also possible that there may have been an enhanced placebo effect due to the novel appearance of the forward-inclined seatpan and the dynamic component. Additionally, this study involved patients with low levels of functional disability, no dominant psychosocial factors and a primarily mechanical behaviour of their LBP (aggravated/eased by spinal postures and movements). This study raised a number of issues to be investigated. These include examining whether seated LBD would also be reduced in a different LBP population, e.g. those with extension-related LBP. This would clarify if the effects seen in the previous study (O’Keeffe et al. 2013) were primarily related to the directional nature of the disorder (flexion-related LBP) and/or the fact that subjects had low disability levels, or simply reflected the placebo effect. Additionally, the forward-inclined seatpan may have reduced sitting discomfort as a result of an increase in lumbar lordosis and altering trunk muscle activation (O’Keeffe et al. 2013). As a backrest is proposed to reduce trunk muscle activation in pain-free subjects, it is therefore beneficial to determine whether a backrest could be as effective in reducing sitting discomfort and altering trunk muscle activation, among those with LBP.