Ultrasonographic Evaluation for the Effect of Extracorporeal Shock Wave Therapy on Gastrocnemius Muscle Spasticity in Patients With Chronic Stroke

Background: Extracorporeal shock wave therapy (ESWT) has been suggested as a useful treatment for spasticity in patients with stroke. To date, most studies have used clinical or biomechanical assessments to determine the effects of treatment. Objectives: To assess the effect of a single session of ESWT through ultrasonographic assessment on spasticity in patients with chronic stroke. Design: Randomized controlled trial. Setting: Rehabilitation center. Participants: Eighteen patients with chronic stroke. Methods: Participants were randomly assigned to an ESWT group (n = 9) or control group (n = 9). In the ESWT group, a single session of ESWT was given in the medial head of the gastrocnemius muscle of the spastic side at 4 Hz, 2000 shots with intensity of stimulation using energy of 0.1 mJ/mm². Sham stimulation was provided by only making sound without putting the device into contact with the skin in the control group. The clinical trial registration number of this study is KCT0002582. Main Outcome Measures: Participants were evaluated prior to the treatment, 30 minutes, 1 week, and 4 weeks after treatment. Clinical measures included Modified Ashworth Scale (MAS), passive range of motion (PROM), and Fugl-Meyer Assessment (FMA). As the primary outcome measure, the ultrasonographic measures were Achilles tendon length (ATL), muscle fascicle length (MFL), muscle thickness (MT), and pennation angle (PA). Results: There were no significant differences between the 2 groups for any demographic or baseline measures. At all follow-up evaluations, improvement was shown in MAS as well as changes from baseline of ultrasonographic measures in the ESWT group compared to the control group. In the case of ultrasonographic measures, the difference between the group was greatest at 4 weeks. At follow-up of 4 weeks, between-group difference was 0.66 points (P =.04) on MAS scores, 5.45 points (P =.004) on ATL scores, 4.95 points (P =.002) on MFL scores, 1.83 points (P <.001) on MT scores, and 3.73 points (P <.001) on PA scores. Conclusions: Some ultrasonographic measures of spasticity as well as MAS were improved after a single session of ESWT. Future studies with larger numbers of subjects compared with other spasticity metrics are necessary to further evaluate the treatment effect of ESWT. Level of Evidence: II.