The Effects of Radial Extra Corporeal Shock Wave and Low-power Laser Therapies on Clinical and Electrophysiological Parameters in Moderate Carpal Tunnel Syndrome: A Blinded Randomized Control Trial

Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy with squeezing of the median nerve and the patient is unable to function properly. There are different physiotherapy interventions for the management of these patients and recently, shock wave therapy and low-power laser (LPL) have been widely used, but there is no strong evidence comparing the effect of shock wave therapy and LLLT. Therefore, this trial was designed to compare the effect of extracorporeal shock wave therapy (ESWT), LPL, and routine interventions on clinical outcomes and electrophysiological parameters in patients with moderate CTS.

Fifty-four patients were randomly assigned to the control (routine interventions), ESWT, and LPL therapy groups. All participants received transcutaneous electrical nerve stimulation (TENS) therapeutic ultrasound, hot pack, mobilization, and stretching for ten sessions over two weeks. Additionally, the ESWT group received radial ESWT in four sessions, and the LPL therapy group received laser in ten sessions. The primary outcomes were pain (assessed by the visual analog scale), function (assessed using the Boston questionnaire (BQ)), hand grip, and finger pinch strength. Secondary outcomes were electrophysiological parameters (distal motor and sensory latency and nerve conduction velocity (NCV) of the median nerve. 

Time group interactions were significant for pain, the symptom severity subscale of BQ, finger pinch, and hand grip strength (p<0.001). Significant improvements were seen in clinical and sensory latency and motor NCV of the median nerve (p<0.05). The ESWT group experienced significant improvements with a large effect size in pain, function, and finger pinch strength compared to the control group (p<0.01). Additionally, the LPL therapy group showed significant changes in the function and finger pinch and hand grip strength compared to the control group. There were no significant differences between the LPL therapy and ESWT groups except for pain in favor of the ESWT group. No significant differences were found among the three groups in electrophysiological parameters (p>0.05).

Although laser therapy increased the efficacy of routine interventions, it seems adding ESWT to the routine treatment may be superior for the management of moderate CTS patients.