Fig. 3

Distribution of Visual Analogue Scale (VAS) scores (millimeters (mm)) at the first four time-points; immediately after injection (1–3 s), 30 s, 1 min and 2 min. Note, in this figure the groups are sorted after pain intensity at injection time. The cut-offs for mild (< 30 mm), moderate (31-70 mm), and severe pain (> 70 mm) is market with reference lines (y-axis)