Immediate effect of extracorporeal shockwave therapy in patients with chronic non-specific low back pain: A randomised placebo-controlled triple-blind trial

Objective To compare the immediate effects of shockwave therapy using two different tips in patients with chronic non-specific low back pain. Design Randomised placebo-controlled study with three intervention groups. Setting The patients recruited for this study were sent for physiotherapy treatment at primary care between May and July 2022. Participants Eighty-one patients with chronic non-specific low back pain aged 18-80 years with pain for >= 3 months and pain intensity >= 3 were randomly recruited for the study. Intervention The patients received a single intervention of radial shockwave therapy with 2000 discharges at 100 mJ energy and 5 Hz frequency using concave or convex tips or placebo treatment. Main measures The primary outcome was pain intensity immediately post-intervention. The secondary outcomes were pressure pain threshold, temporal summation of pain, and functional performance. Data were collected at baseline and post-intervention. Results The post-intervention pain intensity in the concave tip group is an average of two points lower (95% CI = -3.6, -0.4; p < 0.01) than that in the placebo group. The post-intervention pressure pain threshold for the concave tip group was an average of 62.8 kPa higher (95% CI = 0.4, 125.1; p < 0.05) than for the convex tip group and 76.4 kPa higher (95% CI = 14, 138.7; p < 0.01) than in the placebo group. Conclusion The concave tip shockwave therapy is effective in reducing pain and local hyperalgesia in patients with chronic non-specific low back pain.