The goal of this study is to investigate the effects of diaphragmatic breathing exercises in addition to conventional treatment and post isometric relaxation technique on pain, range of motion, functionality, upper extremity stability, and anxiety in individuals with rotator cuff lesions. The study included 32 participants aged between 18 and 65 years, diagnosed with rotator cuff lesions. The control group (n=16) received conventional treatment and the post-isometric relaxation technique, while the respiratory group (n=16) received diaphragmatic breathing exercises in addition to conventional treatment and the post-isometric relaxation technique. The researcher used the Visual Analog Scale (VAS) to assess pain intensity, a universal goniometer to measure range of motion, the Shoulder Pain and Disability Index (SPADI) to evaluate functional status, the Upper Extremity Y-Balance Test to assess upper extremity stability, the State-Trait Anxiety Inventory (STAI) to measure anxiety levels, and a finger-type pulse oximeter to record pulse and oxygen saturation values. The researcher used SPSS V.27 program for statistical analysis of the data.

Shoulder pain is a common musculoskeletal problem affecting a large portion of the general population. Its prevalence ranges from 7% to 25%. One of the most common causes is rotator cuff lesions. Rotator cuff lesions are pathologies that begin with acute tendonitis and progress to partial or full-thickness ruptures as degeneration progresses, leading to extensive progression. Their prevalence among individuals with shoulder pain exceeds 70%. Studies have shown that the incidence increases after age 40, and this rate exceeds 50% in those over age 60. The most common clinical symptoms observed in patients with rotator cuff lesions are decreased shoulder range of motion and flexibility, pain, and impaired shoulder function. This resulting pain and loss of function significantly impact performance in activities of daily living and quality of life. The literature indicates that patients with rotator cuff lesions generally experience additional problems such as depression, anxiety, poor sleep quality, and kinesiophobia. Psychological factors are also thought to play a role in the etiology and chronicity of shoulder pain. In order to achieve a functional movement, parameters such as sufficient November muscle strength, mobility, stability, flexibility, coordination, balance are required along the basic movement pattern. In shoulder pathologies, decreased mobility due to restriction of upper limb movement affects stability. The deterioration of these components leads to a deterioration of functional movement. Conservative or surgical methods can be used in the treatment of rotator cuff lesions. Conservative treatment is known to be the preferred and effective method. Nonsteroidal anti-inflammatory drugs, corticosteroid injections, activity modification, and physiotherapy constitute conservative treatment. Physiotherapy includes rest, stretching, manual therapy, active and passive shoulder exercises, and physical therapy modalities. The primary goals of the treatment program are to reduce pain and dysfunction, regain range of motion by stretching the posterior capsule and other soft tissues, and increase rotator cuff and scapular muscle strength. Post-isometric relaxation is a muscle energy technique (MET) defined as the reduction of tone in the agonist muscle after isometric contraction. It is considered a manual therapy technique, aims to reduce muscle tension by regulating muscle function, and is used in both subacute and chronic settings. Muscle energy techniques have been found to have a positive effect in reducing pain and increasing range of motion in patients with adhesive capsulitis and impingement. Diaphragmatic breathing exercises contribute to core stabilization. Diaphragmatic movements during respiration affect the sympathetic and parasympathetic nervous systems. Recent studies have shown that breathing exercises are among the pain-reducing interventions. Pro-inflammatory markers are reduced with breathing exercises, thus demonstrating their effectiveness in reducing inflammation. Relaxation and deep breathing exercises are believed to reduce pain and improve quality of life in individuals with shoulder pain. Furthermore, breathing exercises and breath awareness enhance psychological and physical well-being and, through the resulting relaxation effect, reduce pain. There are studies demonstrating that diaphragmatic breathing exercises positively impact trunk muscle activity and functional levels in musculoskeletal conditions such as low back pain. Proprioceptive neuromuscular facilitation and breathing exercises applied to patients with frozen shoulder have been shown to reduce pain and increase range of motion. Similarly, diaphragmatic mobilization and diaphragmatic breathing exercises have been found to be effective in reducing pain and improving quality of life in individuals with shoulder pain. A review of the literature reveals a limited number of studies investigating the effectiveness of diaphragmatic breathing exercises in shoulder patients. No studies have been found evaluating the effects of diaphragmatic breathing exercises applied in addition to post-isometric relaxation techniques on upper extremity stability and anxiety parameters in individuals with rotator cuff lesions. The aim of our study was to investigate the effects of diaphragmatic breathing exercises applied in addition to conventional treatment and post-isometric relaxation techniques on pain, range of motion, functionality, upper extremity stability, and anxiety parameters in individuals with rotator cuff lesions.

Inclusion Criteria:

• Being between 18 and 65 years of age,
• Having been diagnosed with a rotator cuff lesion,
• Having unilateral shoulder pain that has persisted for at least 4 weeks,
• Having no cognitive or mental problems,
• Individuals who are willing to participate in the study and are willing to cooperate.

Exclusion Criteria:

• Patients who have received local corticosteroid injections or corticosteroid treatment within the last three months,
• Patients who have a total rotator cuff tear (Stage 3 according to Neer),
• Patients who have shoulder instability or fractures,
• Patients who have a history of shoulder, upper extremity, or thoracic surgery,
• Patients who have neuromuscular disease, unstable angina, malignancy, pulmonary or vascular problems, inflammatory arthritis, vertigo, various vestibular system pathologies, and communication problems.

Participants does not know which type of treatment is received themselves.