RESUMO
STUDY DESIGN: Randomized clinical trial. INTRODUCTION: Eccentric exercise (EE) was shown to be an effective treatment in tendinopathies. However, the evidence of its effectiveness in subacromial syndrome (SS) is scarce. Moreover, consensus has not been reached on whether best results for SS are obtained by means of EE with or without pain. PURPOSE OF THE STUDY: The purpose of this is to compare the effect on pain, active range of motion (AROM), and shoulder function of an exercise protocol performed with pain <40 mm Visual Analog Scale (VAS) and without pain, in patients with SS. METHODS: Twenty-two subjects (mean age: 59 years [Q1 = 48.50-Q3 = 70], 54.5% women) were randomized into a not-painful EE group (NPEE; G0: n = 11) and a painful EE group (PEE; G1: n = 11). The intervention lasted 4 weeks. Pain was recorded using VAS; AROM was measured using a goniometer; and shoulder function using the modified Constant-Murley Score (CMS) before and after intervention. RESULTS: All dependent variables improved significantly in both groups (P < .05): NPEE VAS median: pretest = 55.0 posttest = 28.0; CMS median: pretest = 36.0 posttest = 65.0. PEE VAS median: pretest = 37.0 posttest = 12.0; CMS median: pretest = 35.0 posttest = 59.0. The comparison between groups showed no significant differences, with small effect size values (VAS = 0.09; CMS = 0.21; AROM = 0.12-0.43). DISCUSSION: In contrast to the previous findings, our results suggest that PEE do not add benefit in SS patients compared to NPEE. CONCLUSION: Our results suggest that both interventions are effective in terms of pain, function, and shoulder AROM. Furthermore, PEE does not provide greater benefits. Further studies are needed with long-term follow-up to reinforce these results.