MPWT and TPWL at days 2 and 8 in an experimental model of CCI. Left Panel: A. By day 0, the analytical results of MPWT did not differ among the five groups. B. By day 2, the analytical results of MPWT, * denotes statistical significance vs. other groups with different symbols (†, ‡), p<0.0001. The symbol † indicated CCI + ECSW, CCI + Mel and CCI + ECSW + Mel groups. C. By day 8, the analytical results of MPWT, * denotes statistical significance vs. other groups with different symbols (†, ‡, §), p<0.0001. The symbol ‡ indicated CCI + ECSW and CCI + Mel groups. Right Panel: D. By day 0, the analytical results of MPWT did not differ among the five groups. E. By day 2, the analytical results of TPWL, * denotes statistical significance vs. other groups with different symbols (†, ‡, §), p<0.0001. The symbol ‡ indicated CCI + ECSW and CC I + Mel groups. F. By day 8, the analytical results of TPWL, * denotes statistical significance vs. other groups with different symbols (†, ‡, §), p<0.0001. The symbol ‡ indicated CCI + ECSW and CCI + Mel groups. All statistical analyses were performed by one-way ANOVA and Bonferroni multiple comparison post-hoc test (n = 8 for each group). Symbols (*, †, ‡, §) indicate statistical significance. MPWT = mechanical paw withdrawal threshold; TPWL = thermal paw withdrawal latency; SC = sham control; CCI = chronic constriction injury; ECSW = extracorporeal shock wave; Mel = melatonin.