This randomized controlled trial aims to investigate the acute effects of diaphragmatic breathing exercises added to soft tissue mobilization and percussive therapy on pain intensity, functional disability, and pressure pain threshold in operating room nurses experiencing upper trapezius pain after surgery-related work activities.

Participants will be operating room nurses working in a hospital operating theater who report upper trapezius pain and tenderness within 30 minutes after completing a surgical procedure. Eligible participants will be randomly assigned to either an intervention group receiving soft tissue mobilization, percussive therapy, and diaphragmatic breathing exercises, or a control group receiving soft tissue mobilization and percussive therapy alone.

Pain intensity will be assessed using the Visual Analog Scale (VAS), functional disability using the Neck Disability Index (NDI), and mechanical pain sensitivity using Pressure Pain Threshold (PPT) measurements. Assessments will be performed immediately before and after a single treatment session. The study aims to determine whether the addition of diaphragmatic breathing exercises provides additional benefits in reducing pain and improving function in the acute postoperative working period of operating room nurses.

Operating room nurses are exposed to prolonged static postures, repetitive upper extremity movements, and sustained neck and shoulder loading during surgical procedures. These occupational demands frequently result in upper trapezius pain, tenderness, and functional limitations. Acute musculoskeletal symptoms experienced after surgical procedures may negatively affect both occupational performance and quality of life.

Soft tissue mobilization and percussive therapy are commonly used physiotherapy interventions for reducing muscle tension, improving local circulation, and decreasing pain sensitivity. Diaphragmatic breathing exercises may further contribute to pain reduction through autonomic nervous system regulation, parasympathetic activation, and decreased physiological stress responses. Although each intervention has been investigated separately, evidence regarding their combined acute effects in operating room nurses is limited.

The purpose of this randomized controlled trial is to evaluate whether the addition of diaphragmatic breathing exercises to a treatment protocol consisting of soft tissue mobilization and percussive therapy provides additional benefits for pain reduction, functional improvement, and pressure pain threshold in operating room nurses experiencing upper trapezius pain following surgery-related work activities.

Participants meeting the eligibility criteria will be randomly allocated to one of two groups. The intervention group will receive soft tissue mobilization, percussive therapy, and diaphragmatic breathing exercises, while the control group will receive soft tissue mobilization and percussive therapy only. All interventions will be administered during a single treatment session under physiotherapist supervision.

Outcome measures will include pain intensity assessed by the Visual Analog Scale (VAS), functional disability assessed by the Neck Disability Index (NDI), and mechanical pain sensitivity assessed by Pressure Pain Threshold (PPT) measurements using a digital algometer. Measurements will be obtained immediately before and immediately after the intervention session.

The findings of this study may contribute to the development of practical physiotherapy strategies for managing acute work-related upper trapezius pain among operating room nurses and may help identify the additional value of diaphragmatic breathing exercises within a multimodal physiotherapy approach.

Inclusion Criteria:

• Aged between 22 and 55 years.
• Operating room nurse actively working in the hospital operating theater.
• Reporting upper trapezius pain and tenderness within 30 minutes after completion of a surgical procedure.
• Willing to participate and able to provide written informed consent.

Exclusion Criteria:

• History of trauma, surgery, or chronic disease affecting the neck or shoulder region.
• Regular participation in breathing exercise programs.
• Psychiatric disorders requiring anxiolytic or antidepressant medication.
• Pregnancy.
• Skin disease, infection, or open wound in the treatment area.
• Severe cardiovascular disease or uncontrolled hypertension.
• Contraindications to manual therapy, soft tissue mobilization, percussive therapy, or breathing exercises.

Individual participant data will not be shared to protect participant confidentiality and privacy.