Comparing the effect of radial extracorporeal shock waves with different energy flux densities on forearm spasticity after stroke: A randomized controlled trial

Background: To explore the effect of radial extracorporeal shock wave therapy (rESWT) on forearm spasticity in stroke patients and to compare the effect of low energy flux density (EFD) and medium EFD rESWT on forearm spasticity after stroke. Methods: Ninety stroke patients who met the inclusion criteria of this study were randomly divided into a control group, intervention group A and intervention group B, with 30 patients in each group. The control group received placebo rESWT. Group A received a low EFD (energy flux density of 0.08 mJ/mm 2 ); Group B received a medium EFD (energy flux density of 0.16 mJ/mm 2 ). The interventions continued for 4 weeks, once a week. Muscle tension and muscle stiffness were evaluated by the modified Ashworth scale (MAS), and shear wave velocity (SWV) was measured by ultrasound elastography before and after treatment. Results: ① MAS: After treatment, the MAS scores of muscle groups in intervention groups A and B were lower than those before treatment, and the differences were statistically significant ( P  < 0.01). After treatment, the MAS scores of the wrist flexor muscle group in groups A and B were significantly lower than that in the control group ( P  < 0.05). ② SWV: After treatment, the SWV of the flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP), flexor carpi radialis (FCR), and pronator teres (PT) in group A were significantly lower than those before treatment (P < 0.05), and the SWV of FDS, FDP, flexor carpi ulnaris (FCU), FCR, and PT in group B were significantly lower than those before treatment (P < 0.05). The SWVs of FDS, FDP and FCR in group A were significantly lower than those in the control group (P < 0.05). The SWVs of the FDS, FDP, FCR and PT in group B were significantly lower than those in the control group (P < 0.05). Conclusion: Both low- and medium-EFD rESWT are effective for forearm spasticity in stroke patients. The effect of medium EFD rESWT is slightly better than that of low EFD rESWT, but the difference is not significant. Trial registration: Clinical trial registration numbers and date of registration: ChiCTR2300075610, Registered 11 September 2023.