Focused extracorporeal shock wave therapy combined with supervised eccentric training for supraspinatus calcific tendinopathy

BACKGROUND: Extracorporeal shockwave therapy (ESWT) is effective in reducing shoulder pain and improving function in calcific supraspinatus tendinopathy. Eccentric exercise has been introduced as an effective treatment choice for Achilles tendinopathy, but poor evidence exists about its role in the treatment of rotator cuff tendinopathy. AIM: To investigate if adding a supervised eccentric training of the shoulder abductor muscles could improve the outcome of ESWT. DESIGN: Pre-post intervention pilot study with matched control-group. SETTING: Outpatient, University Hospital. POPULATION: Twenty-two subjects affected by painful supraspinatus calcific tendinopathy. METHODS: The study-group was assigned to receive focal ESWT(f-ESWT) plus a supervised eccentric training (SET) of the shoulder abductor muscles. The matched control-group received f-ESWTonly. The post-treatment assessment at follow-up (T1) was performed nine weeks after the enrollment (T0). We assessed shoulder pain and function by the means of a numeric rating scale (p-NRS) and a DASHscale. As secondary outcome, we measured the isometric strength of the abductor muscles of the affected shoulder using a handheld dynamometer. RESULTS: At T1, we recorded a significant decrease in pain (P<0.001) and an improvement in upper limb function (P<0.001) in both groups. However, we observed no statistical differences in favor of the study-group, in terms of p-NRSand DASHtotal score. Amild increase (+13% from baseline) of the maximum isometric abduction strength was noticed in the study group at T1. CONCLUSIONS: Our findings did not support the hypothesis that adding a supervised eccentric training of the shoulder abductor muscles could improve the outcome (pain and function) of shock wave therapy. CLINICALREHABILITATION IMPACT: Our study confirmed that f-ESWT is effective in reducing shoulder pain and improving function in calcific supraspinatus tendinopathy. Adding a supervised eccentric training, focused on the abductor muscles, was useful to improve maximum isometric abduction strength, but appeared to give no advantage in the short-term outcome of shock wave therapy.