Fig. 1. Effects of popliteal sciatic perineural infusion of either ropivacaine or placebo on average pain at rest (A ) and worst pain overall (B ) following moderately painful lower extremity surgery (scale: 0–10). Note: the infusion was discontinued after postoperative day two as indicated by the horizontal line. Data are expressed as median (horizontal bar) with 25th–75th(box) and 10th–90th(whiskers) percentiles for patients randomly assigned to receive either 0.2% ropivacaine (n = 15) or 0.9% saline placebo (n = 15). For tightly clustered data (e.g. , Panel A, postoperative day 0, ropivacaine group), the median approximated the 10th, 25th, and 75thpercentile values. In this case, the median is zero and no box is evident, although the 90thpercentile is noted. P < 0.05:*, compared to saline for a given postoperative day.