 Scientific evidence of conservative management of subacromial pain syndrome is conflicting. There is evidence that eccentric exercise programs are effective at medium term for this pain condition. The inclusion of other therapeutic modalities is still controversial. A recent study suggests that the inclusion of US-guided percutaneous electrolysis combined with eccentric exercises can be effective at short-term for this condition. The objective of this randomized clinical trial is to determine the effectiveness at short- and long-term of the inclusion of US-guided percutaneous electrolysis EPE into a eccentric exercise protocol for the management of patients with subacromial pain syndrome for pain, function, disability and pressure pain sensitivity. 