This study aims to evaluate the effectiveness of electroacupuncture combined with vacuum cupping therapy in treating simple periarthritis of the shoulder associated with the traditional medicine syndrome of Qi stagnation and blood stasis. Shoulder periarthritis is a common condition that causes pain, stiffness, and limited movement of the shoulder due to injury or inflammation of the muscles, tendons, ligaments, and surrounding soft tissues. It can interfere with daily activities such as dressing, lifting objects, sleeping, and working.

Electroacupuncture is commonly used to relieve shoulder pain and improve shoulder function. Vacuum cupping therapy is another non-drug treatment that may help improve blood circulation, reduce muscle tightness, decrease pain, and improve mobility. However, there is currently limited evidence about whether combining electroacupuncture with vacuum cupping provides better results than electroacupuncture alone in patients with shoulder periarthritis and Qi stagnation-blood stasis syndrome. This study is being conducted to determine whether the combined treatment is more effective and safe.

A total of 54 participants with simple shoulder periarthritis and Qi stagnation-blood stasis syndrome will be enrolled in the study. Participants will be randomly assigned to one of two groups:

Group 1: treatment with electroacupuncture alone. Group 2: treatment with electroacupuncture combined with vacuum cupping therapy.

All participants will also receive advice on shoulder exercises, posture, and daily activities to support recovery. Treatments will be performed by licensed traditional medicine practitioners.

Each participant will take part in the study for two weeks. Assessments will be performed before treatment, after one week, and after two weeks. The study will evaluate:

Pain intensity using the Visual Analogue Scale (VAS). Shoulder pain and disability using the Shoulder Pain and Disability Index (SPADI).

Shoulder range of motion using the McGill-McRomi Range of Motion Index. Any side effects or unwanted events related to treatment. Possible benefits of participating in this study include reduced shoulder pain, improved movement and daily function, and close monitoring by health care professionals. Participants may also benefit from receiving non-drug therapies at no cost during the study period. The findings of this research may help improve future treatment options for patients with shoulder pain.

Possible risks of electroacupuncture include mild pain at the needle site, minor bleeding, bruising, dizziness, or fainting. Possible risks of vacuum cupping include temporary discomfort, skin redness, bruising, or mild pain in the treated area. These side effects are usually mild and temporary. If any unexpected problem occurs, participants will receive prompt medical attention.

Participation in this study is completely voluntary. Participants may refuse to join or may withdraw from the study at any time without affecting their usual medical care. All personal information collected during the study will remain confidential and will only be used for research purposes.

Inclusion Criteria:

• Patients between 18 and 70 years old.
• Pain intensity score on the Visual Analogue Scale (VAS) between 4 and 7.
• Diagnosis of rotator cuff and/or long head of the biceps tendonitis according to the guidelines issued by the Ministry of Health of Vietnam.
• Mechanical pain that increases during movements such as abduction or raising the arm.
• Presence of tender points at the long head of the biceps tendon or supraspinatus tendon .
• Pain that increases during resisted contraction tests, such as the Jobe test or Palm-up test.
• Absence of limitation in the passive range of motion of the shoulder.
• Ultrasound findings showing a hypoechoic tendon or evidence of calcification.
• Absence of motor weakness or paralysis.
• Diagnosis of the TCM syndrome "Qi Stagnation and Blood Stasis"

Exclusion Criteria:

• Patients who do not agree to participate in the study.
• Diagnosis of pseudo-paralysis, acute calcific periarthritis, or frozen shoulder.
• Shoulder pain caused by cervical nerve root lesions.
• Shoulder pain originating from apical lung tumors, coronary artery disease, or myocardial infarction.
• Specific joint lesions caused by infection, tuberculosis, or rheumatoid arthritis.
• Bone pathologies including fractures, dislocations, or osteonecrosis of the humeral head.
• Shoulder dysfunction resulting from stroke or hemiplegia.
• Women who are pregnant.
• Patients with mental illness.
• Contraindications for vacuum cupping, such as acute skin inflammation, open wounds, or alcohol consumption.
• Contraindications for electroacupuncture, including cardiac pacemakers, heart failure, or local skin ulcers.
• Current participation in another intervention study.
• Use of painkillers, muscle relaxants, or within the last week.
• Use of anticoagulants or a history of hemophilia.