Transcutaneous Auricular Vagus Nerve Stimulation Added to Physiotherapy for Adhesive Capsulitis (taVNS-AC)

Effect of Transcutaneous Auricular Vagus Nerve Stimulation Added to Standard Physiotherapy on Pain, Function, and Quality of Life in Patients With Shoulder Adhesive Capsulitis: A Randomized Controlled Trial

This randomized, sham-controlled study will evaluate whether transcutaneous auricular vagus nerve stimulation (taVNS), when added to standard physiotherapy, improves pain, shoulder function, range of motion, and quality of life in adults with adhesive capsulitis.

A total of 40 participants aged 18 to 65 years will be randomly assigned to one of two groups. Both groups will receive 15 sessions of standard physiotherapy over 3 weeks. In addition, one group will receive active taVNS for 30 minutes per day, while the other group will receive sham stimulation for the same duration and frequency. Assessments will be performed before treatment and after the 15th treatment session using pain, shoulder disability, quality-of-life, and shoulder range-of-motion measurements.

Study Overview

• Status: Recruiting
• Conditions: Adhesive Capsulitis of the Shoulder
• Intervention / Treatment: Device: Active Transcutaneous Auricular Vagus Nerve Stimulation (taVNS); Other: Conventional Physiotherapy; Device: Sham Transcutaneous Auricular Vagus Nerve Stimulation

Detailed Description

Adhesive capsulitis is a musculoskeletal condition characterized by shoulder pain and progressive restriction of active and passive range of motion. Although physiotherapy, therapeutic exercise, and manual therapy are commonly used, pain relief and functional recovery may be incomplete in some patients. Therefore, additional non-invasive treatment approaches that may enhance the effects of rehabilitation are clinically relevant.

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique that stimulates the auricular branch of the vagus nerve. It may influence pain modulation, autonomic nervous system regulation, and inflammatory pathways. Previous studies have reported potential benefits of auricular vagus nerve stimulation in several chronic pain conditions; however, evidence regarding its use in adhesive capsulitis remains limited.

The objective of this study is to determine whether active taVNS added to standard physiotherapy provides greater clinical improvement than sham taVNS added to the same physiotherapy program. The main hypothesis is that participants receiving active taVNS will demonstrate greater reductions in pain and shoulder-related disability after treatment. Secondary objectives are to evaluate changes in shoulder range of motion and health-related quality of life and to assess the tolerability of the intervention.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Muhsin Doran, MD; Phone Number: 05340807940; Email: muhsin-doran@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34381
      • Recruiting
      • Liv hospital Vadistanbul
      • Contact: Muhsin Doran, MD; Phone Number: 05340807940; Email: muhsin-doran@hotmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age between 18 and 65 years.
• Clinical diagnosis of adhesive capsulitis confirmed by physical examination and, when clinically indicated, imaging.
• Shoulder pain and limitation of shoulder range of motion for at least 3 months.
• Provision of written informed consent.
• General health status sufficient to participate in standard physiotherapy and active or sham transcutaneous auricular vagus nerve stimulation.
• Ability to comply with the planned treatment sessions and outcome assessments.

Exclusion Criteria:

• Shoulder stiffness secondary to trauma, surgery, infection, or tumor.
• Rotator cuff tear, advanced glenohumeral osteoarthritis, or inflammatory rheumatic disease.
• Glucocorticoid injection into the affected shoulder within the previous 3 months.
• Surgical intervention involving the affected shoulder within the previous 6 months.
• Active infection or skin lesion in the shoulder region.
• Cervical radiculopathy, brachial plexopathy, stroke, or another neurological disorder affecting the upper extremity.
• Presence of a cardiac pacemaker or another implanted electronic device.
• Pregnancy or breastfeeding.
• Serious systemic disease or cognitive impairment that may prevent compliance with the study protocol.
• Known intolerance or previous adverse reaction to transcutaneous electrical stimulation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Standard Physiotherapy Plus Active taVNS; Participants receive 15 sessions of standard physiotherapy over 3 weeks. Active transcutaneous auricular vagus nerve stimulation is administered for 30 minutes during each treatment session in addition to the physiotherapy program.	Device: Active Transcutaneous Auricular Vagus Nerve Stimulation (taVNS); Active transcutaneous auricular vagus nerve stimulation will be administered for 30 minutes per session during each of 15 treatment sessions over 3 weeks, in addition to standard physiotherapy. Electrical stimulation will be delivered transcutaneously through an auricular electrode to a vagally innervated region of the external ear. The physiotherapist administering the stimulation will be aware of group allocation, while participants and the outcomes assessor will remain blinded.; Other: Conventional Physiotherapy; Participants will receive 15 standard physiotherapy sessions over 3 weeks, with five sessions per week. The program will include pain-relieving physical therapy modalities, glenohumeral and scapulothoracic joint mobilization, passive and active-assisted range-of-motion exercises, capsular stretching, and progressive strengthening exercises for the rotator cuff and scapular stabilizing muscles. Treatment intensity and exercise progression will be individualized according to pain severity, irritability, and range-of-motion limitations. The same physiotherapy protocol will be administered to both study arms.
Sham Comparator: Standard Physiotherapy Plus Sham taVNS; Participants receive 15 sessions of standard physiotherapy over 3 weeks. In addition, sham transcutaneous auricular vagus nerve stimulation is administered for 30 minutes with the same frequency and treatment schedule as the active stimulation.	Other: Conventional Physiotherapy; Participants will receive 15 standard physiotherapy sessions over 3 weeks, with five sessions per week. The program will include pain-relieving physical therapy modalities, glenohumeral and scapulothoracic joint mobilization, passive and active-assisted range-of-motion exercises, capsular stretching, and progressive strengthening exercises for the rotator cuff and scapular stabilizing muscles. Treatment intensity and exercise progression will be individualized according to pain severity, irritability, and range-of-motion limitations. The same physiotherapy protocol will be administered to both study arms.; Device: Sham Transcutaneous Auricular Vagus Nerve Stimulation; Sham transcutaneous auricular vagus nerve stimulation will be administered for 30 minutes per session during each of 15 treatment sessions over 3 weeks, in addition to standard physiotherapy. The sham procedure will follow the same session frequency and duration as the active intervention but will be applied according to a prespecified sham protocol that is not expected to produce therapeutic vagal stimulation. The physiotherapist administering the intervention will be aware of group allocation, while participants and the outcomes assessor will remain blinded.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Shoulder Pain and Disability Index (SPADI) Total Score	The Shoulder Pain and Disability Index (SPADI) is a 13-item patient-reported questionnaire consisting of a 5-item pain subscale and an 8-item disability subscale. The total score ranges from 0 to 100, with higher scores indicating greater shoulder pain and disability. The primary outcome will be the change in the SPADI total score from baseline to the assessment performed after completion of the 15th treatment session.	Baseline and immediately after completion of the 15th treatment session, approximately 3 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Shoulder Pain Intensity Assessed With the Visual Analog Scale (VAS)	Shoulder pain intensity will be assessed using a 10-cm Visual Analog Scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Higher scores indicate greater pain intensity. The outcome will be calculated as the change in VAS score from baseline to the assessment performed after completion of the 15th treatment session.	Baseline and immediately after completion of the 15th treatment session, approximately 3 weeks
Change in Shoulder Flexion Range of Motion	Change in Shoulder Flexion Range of Motion Change in Shoulder Abduction Range of Motion Change in Shoulder Extension Range of Motion Change in Shoulder Internal Rotation Range of Motion Change in Shoulder External Rotation Range of Motion Change in Shoulder Horizontal External Rotation Range of Motion Change in Shoulder Horizontal Abduction Range of Motion Change in Shoulder Horizontal Adduction Range of Motion	Baseline and immediately after completion of the 15th treatment session, approximately 3 weeks
Change in Health-Related Quality of Life Assessed With the 36-Item Short Form Health Survey (SF-36)	Health-related quality of life will be assessed using the 36-Item Short Form Health Survey (SF-36). The questionnaire evaluates eight domains: physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health. Each domain is scored from 0 to 100, with higher scores indicating better health-related quality of life. Changes in domain scores from baseline to the post-treatment assessment will be evaluated.	Baseline and immediately after completion of the 15th treatment session, approximately 3 weeks

Collaborators and Investigators

• Sponsor: Muhsin Doran
• Investigators: Principal Investigator: Muhsin Doran, Liv hospital Vadistanbul

Study record dates

Study Major Dates

• Study Start (Actual): June 10, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: July 14, 2026
• First Submitted That Met QC Criteria: July 14, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 14, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Bursitis
• Other Study ID Numbers: LIV-FTR-taVNS-AC-2026-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared. Study findings will be reported only in aggregate form to protect participant confidentiality, and no external IPD-sharing procedure has been established for this study.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No