The goal of this clinical trial is to evaluate whether pulsed electromagnetic field (PEMF) therapy delivered via the Super Inductive System (SIS), integrated into a multimodal rehabilitation program, improves pain, function, pressure pain threshold, muscle strength, psychological status, and quality of life in adults with shoulder tendinopathies.

The main questions it aims to answer are:

• Does the addition of PEMF (SIS) therapy reduce pain intensity and improve pressure pain threshold compared to standard balneophysiotherapy?
• Does PEMF (SIS) therapy improve shoulder function, muscle strength, psychological status, and quality of life? The study will compare a multimodal rehabilitation program supplemented with PEMF (SIS) therapy to standard balneophysiotherapy to determine whether the addition of PEMF (SIS) provides superior clinical outcomes.

Participants will:

• Undergo a multimodal rehabilitation program including balneophysiotherapy
• Be assigned to receive either standard treatment or treatment supplemented with PEMF (SIS) therapy
• Be evaluated at baseline (admission), immediately after treatment completion (discharge), and at 4 weeks after treatment using validated clinical instruments assessing pain, function, pressure pain threshold, muscle strength, psychological status, depressive symptoms, and quality of life.

Shoulder tendinopathies are a common cause of pain, functional limitation, and reduced quality of life, with a significant impact on daily activities. Their clinical presentation is heterogeneous, involving not only structural and functional impairments but also activity limitations and participation restrictions.

Conservative management remains the first-line approach and typically includes multimodal rehabilitation programs incorporating balneophysiotherapy, exercise therapy, and physical modalities. Although these interventions are widely used and have demonstrated clinical benefits, the optimal combination of therapeutic modalities remains a subject of ongoing research.

Pulsed electromagnetic field (PEMF) therapy delivered via the Super Inductive System (SIS) is a non-invasive intervention with potential analgesic, neuromodulatory, and regenerative effects. However, evidence regarding its additional benefit when integrated into standard multimodal rehabilitation programs for shoulder tendinopathies is still limited.

Given the multifactorial nature of shoulder tendinopathies, a multidimensional assessment approach is required. This study is based on the framework of the International Classification of Functioning, Disability and Health (ICF) and aligned with OMERACT recommendations, allowing a comprehensive evaluation of clinical outcomes across multiple domains.

The aim of this study is to compare the effectiveness of PEMF therapy delivered via SIS, integrated into a multimodal rehabilitation program, with standard balneophysiotherapy in patients with shoulder tendinopathies.

Participants are allocated to either a control group receiving standard treatment or an experimental group receiving the same rehabilitation program supplemented with PEMF (SIS) therapy. Clinical outcomes, including pain intensity, shoulder function, pressure pain threshold, muscle strength, psychological status, depressive symptoms, and quality of life, are assessed at baseline (admission), immediately after treatment completion (discharge), and at 4 weeks after treatment.

This study seeks to determine whether the addition of PEMF (SIS) therapy provides superior outcomes within a multimodal rehabilitation strategy and supports a personalized, multidimensional approach to the management of shoulder tendinopathies.

Inclusion Criteria:

• Adults aged between 18 and 70 years.
• Patients with chronic shoulder pain lasting more than 3 months, of non-traumatic origin, persistent despite prior conservative treatment.
• Clinical diagnosis of shoulder tendinopathy and/or subacromial pain syndrome based on medical history and physical examination.
• Presence of shoulder pain and functional limitation confirmed by clinical assessment and baseline functional evaluation (SPADI).
• Ability to comply with the treatment protocol and attend scheduled follow-up assessments.
• Provision of written informed consent prior to participation.

Exclusion Criteria:

• Full-thickness rotator cuff tears with surgical indication.
• Recent major shoulder trauma (within the last 6 months).
• Active systemic inflammatory or rheumatologic diseases.
• Presence of metallic implants in the treatment area or implanted electronic devices (e.g., pacemaker).
• Neurological disorders affecting the upper limb.
• Contraindications to balneotherapy (e.g., severe cardiovascular disease, renal failure, severe dermatological conditions).
• Decompensated chronic diseases at the time of enrollment (cardiovascular, hepatic, renal, respiratory, or neurological).
• Skin lesions at the site of treatment application.
• Pregnancy or breastfeeding.
• Active neoplastic disease.
• Decompensated psychiatric disorders.
• History of hypersensitivity to natural therapeutic factors used in balneotherapy.
• Refusal to participate or inability to provide informed consent.