The NRS score for back pain showed statistically significant improvement in the 5th session (P = 0.034) and at 1-month follow-up (P = 0.047) compared to the baseline value. In addition, statistically significant improvement in the leg NRS score was seen in the 5th session (P = 0.010) and at 1-month follow-up (P = 0.006). Because the MCIC for NRS scores in the present study was 20 points, NRS score improvements in back and leg pain were not clinically significant in the 5th session or at 1-month follow-up (Figs. 3 and 4) (Table 2).Fig. 3Trend in back pain intensity during the trialFig. 4Trend in leg pain intensity during the trialTable 2Mean values of back pain, leg pain and functional disability during the trialOutcomesBaselinea1st session5th session1 monthTimes with statistically significant differences (P-value)Back NRS44.95 ± 26.1842.00 ± 25.3030.50 ± 19.3229.75 ± 16.42Baseline - 5th session (0.034)Baseline - 1 month (0.047)Leg NRS49.50 ± 23.9447.25 ± 24.3536.00 ± 16.9033.75 ± 13.75Baseline - 5th session (0.010)Baseline - 1 month (0.006)ODI14.45 ± 4.40n.d.11.35 ± 4.5410.95 ± 4.27Baseline - 5th session (0.001)Baseline - 1 month (0.001)Abbreviations: NRS numerical rating scale, ODI Oswestry Disability Index, n.d. not determinedaValues are mean ± SD