Effects of Percutaneous Electrical Stimulation in Patients With Chronic Supraspinatus Tendinopathy

Inclusion Criteria: * Subjects attending the shoulder unit of the traumatology and orthopedic surgery service at Clínica HLA Vistahermosa (TraumaVist) who are clinically diagnosed with supraspinatus tendinopathy (M75.1 Rotator cuff tendinopathy - ICD-10), according to the following criteria (Desmeules et al., 2025). * Participants of both sexes, aged between 18 and 65 years, diagnosed with chronic supraspinatus tendinopathy, or any of the related terms, provided they also meet the conditions detailed below. * Painful symptoms associated with the insertion area of the supraspinatus tendon, present for at least 3 months, of non-traumatic origin, which increase with palpation (score equal to or greater than 3/10 on a numerical pain scale) and with resisted movements, and not associated with signs of nerve root irritation. * Structural changes in the supraspinatus tendon (tendinosis), observed via ultrasound or MRI, and confirmed by a specialist physician. * Positive results in at least 2 of the 5 assessment tests: Hawkins-Kennedy, Neer, Jobe, painful arc of motion, and resisted external rotation. * Attend the center, referred by a specialist in traumatology and orthopedics, with a prescription for physiotherapy treatment. Exclusion Criteria: * Individuals with any of the following circumstances will be excluded: * Intratendinous calcification in the supraspinatus muscle. * Partial or complete tear of any rotator cuff structure. * Serious illnesses, diabetes, or systemic inflammatory disease. * Pregnant women (at any stage of pregnancy). * Presence of concomitant pathology in the affected shoulder joint complex at the time of recruitment (previous trauma, capsulitis, fracture and dislocation, history of surgery, entrapment neuropathies, among others). * Regular analgesic or anti-inflammatory pharmacological treatment, including corticosteroid injections in the area, within the 6 months prior to recruitment. * Difficulty understanding and following the intervention program, in any of its modalities (percutaneous electrical stimulation and exercises). • Individuals with belonephobia (fear of needles), or a contraindication for the application of either percutaneous electrical stimulation technique (EP or PENS). * High scores on the Tampa - TSK-11 kinesiophobia scale (≥36 points).