Participants received four injections with hypertonic saline along with lidocaine or matching placebo in randomised order : A : received hypertonic saline/told hypertonic saline ; B : received hypertonic saline + lidocaine/told hypertonic saline ; C : received hypertonic saline + placebo/told hypertonic saline + pain killer ; D : received hypertonic saline + lidocaine/told hypertonic saline + pain killer .