Validation of a sham novel neural mobilization technique in patients with non-specific low back pain: A randomized, placebo-controlled trial

Background: There is no validated sham neural mobilization (NM) intervention for lower quadrant conditions. A suitable sham NM comparator will allow to blind patients with low back pain (LBP) and reduce bias by limiting the confounding effects of expectations. Objective: The primary aim was to develop a sham NM technique in patients with non-specific LBP and assess its validity in supplying a suitable blinding. Secondly, we compared the short-term effects of NM and the sham comparator on pain and the straight leg raise. Design: A randomized placebo-controlled trial in which participants and assessors were blinded. Method: Fifty one patients (20 men,31 women), aged 22-65 years (43 + 12y) were allocated randomly to a NM group (n = 26) or a sham NM group (n = 25). The primary outcome of believability of the sham technique was measured one week after the intervention. Secondary outcomes of pain intensity and the straight leg raise range-of-motion were assessed at baseline, immediately after the intervention and one week after. Results: The believability of the sham technique in terms of the frequencies of perceived group assignment showed no differences between groups. Eighteen participants believed they had received the experimental NM technique in the experimental group (69.2%) and 14 in the placebo NM group (56%). Pain and the straight leg raise changes did not show differences between groups. Conclusions: The novel sham NM demonstrated to be a believable intervention, capable of supplying a suitable blinding. Both groups showed similar short term perceived effects on pain and the straight leg raise.