Introduction:
Post-mastectomy lymphoedema has long been considered a risk factor for median nerve compression and pain in the wrist, causing carpal tunnel syndrome, so this study aimed to evaluate the effects of extracorporeal shock wave treatment on carpal tunnel syndrome post-mastectomy lymphoedema.

Methods:
Sixty-eight females diagnosed with CTS and hand lymphoedema by a physician and referred to the physiotherapy clinic were randomised into two equal groups. The experimental group received focal extracorporeal shock wave therapy (fECSWT), and the control group received sham fECSWT for 1 session per week combined with 2 conventional physiotherapy sessions (manual lymph drainage, compression bandage, exercise, and skin care) per week for 4 weeks. Pain intensity by the Visual Analogue Scale, nerve conduction velocity disability by the Boston Carpal Tunnel Questionnaire, and limb volume by tape measurement were measured before and after 4 weeks of treatment. Two-way mixed MANOVA was conducted to investigate the effect of treatment and time on all measured variables. A significance level of p < 0.05 was set for all statistical tests.

Results:
After treatment, there was a significant reduction in pain intensity (effect size = 1.46, MD = 0.8 cms), symptoms severity (effect size = 1.04, MD = 3.03) and limb volume (effect size = 0.04, MD = 9.79 ml), and a reduction in sensory and motor distal latency with effect size = 0.78 and 0.83, MD = −0.18 ms and 0.17 ms, respectively, in both groups, favouring the experimental group.

Conclusions:
Extracorporeal shock wave therapy has a positive clinically relevant effect in reducing the pain and intensity of symptoms associated with carpal tunnel syndrome with improving functionality in those with post-mastectomy lymphoedema over conventional therapy alone.