Is extracorporeal shockwave therapy combined with isokinetic exercise more effective than extracorporeal shockwave therapy alone for subacromial impingement syndrome? A randomized clinical trial

STUDY DESIGN: Single-blind randomized trial. BACKGROUND: Extracorporeal shockwave therapy (ESWT) has been shown to produce good results in the treatment of subacromial impingement syndrome (SAIS). The efficacy of a combined administration of ESWT and isokinetic exercise (IE) has not yet been studied. OBJECTIVES: To evaluate the efficacy of focused ESWT combined with IE for the rotator cuff versus focused ESWT alone in the treatment of SAIS. The secondary objective was to assess the isokinetic torque recovery (external rotation at 210°/s, 180°/s, and 120°/s). METHODS: Thirty participants with SAIS were randomly assigned to a focused-ESWT group or focused ESWT-plus-IE group. Subjects of both groups received 3 treatment sessions of focused ESWT over a period of 10 days. Participants in the second group also received IE for 10 therapy sessions. Outcome measures were the Constant-Murley score (CMS), the visual analog scale (VAS), and isokinetic parameters (peak torque and total work calculated from 5 repetitions) measured with the isokinetic test. Subjects were assessed at baseline, 10 days after the last treatment session with focused ESWT, and after 2 months of follow-up. RESULTS: At 2 months posttreatment, participants in the focused ESWT-plus-IE group showed significantly less pain (focused-ESWT VAS, 3.4 ± 0.8 versus focused ESWT-plus-IE VAS, 1.5 ± 0.5; P<.001) and greater improvement in functionality (focused-ESWT CMS, 75.9 ± 6.7 versus focused ESWT-plus-IE CMS, 92.1 ± 6.3; P<.001) and muscle endurance than the subjects in the focused-ESWT group. CONCLUSION: In subjects with SAIS, combined administration of focused ESWT and IE for the rotator cuff resulted in greater reduction of pain, as well as superior functional recovery and muscle endurance in the short to medium term, compared with ESWT alone. LEVEL OF EVIDENCE: Therapy, 2b. Trial registration: unregistered 2011 trial.