This is a parallel-group randomised clinical trial:

Primary purpose: To analyse the clinical changes produced by two different physiotherapy treatments (Intratissue Percutaneous Electrolysis and Dry Needling) for myofascial trigger points in the infraspinatus muscle in subjects with non-specific shoulder pain.

Hypothesis: A physiotherapy treatment including Intratissue Percutaneous Electrolysis therapy present greater benefits in terms of pain reduction and increased mobility and functionality rather than Dry Needling treatment in subjects with non-specific shoulder pain.

The intervention consisted of 3 treatment sessions, different according to the group, once a week. Seven evaluation points were performed, two pre-intervention evaluations one week apart and after the second one the first treatment session was performed. The third and fourth assessments were prior to the second and third treatment sessions, one week apart. The fifth, sixth and seventh assessments were conducted one week, one month and two months after the last treatment session in each group.

Inclusion Criteria:

• Both male and female patients suffering from shoulder pain during at least three months before intervention protocol starts.
• Patients with free passive range of movement and at least 15 degrees active external rotation in the affected shoulder.
• Patients willing to participate in the study and return for all scheduled follow-up visits.
• Patient is capable of giving, and has given, written informed consent.

Exclusion Criteria:

• Patients with a previous medical diagnosis (tendon rupture, bursitis, etc.) or a traumatic history that justifies shoulder pain.
• Patients with unstable or uncontrolled angina, uncontrolled heart failure, or serious uncontrolled ventricular arrhythmias.
• Patients allergic to metal or those who have needle phobia.
• Patient that has participated in any other shoulder pain treatment research study within 30 days prior.
• Patients that had prior shoulder surgery.
• Patients that are currently being treated with a narcotic or NSAIDs and/or has used analgesics or NSAIDs within the 72 hours prior.
• Patients that has a known bleeding disorder or that are currently being treated with anticoagulant therapy.
• Pregnant women.