Aim: The aim of this study is to compare the effects of platelet-rich plasma application with additional exercise and only exercise application on pain, muscle strength, functionality and quality of life in subacromial impingement syndrome.

Material and Method: 56 patients who applied to the clinic with the complaint of shoulder pain and were diagnosed with Subacromial impingement syndrome between February 2022 and February 2023 will be included in the study. After giving the necessary verbal and written information about the study, the patients with informed consent will be randomized and divided into 2 groups of 28 people. The cases will be randomly divided into groups and their treatment will be done by the same researchers. Evaluation will be carried out by another investigator blinded to which group the participants belong to before and after the treatment. After the initial evaluations are completed, the 1st group will be given a home exercise program that they will apply every day for 8 weeks, and the 2nd group will be given 2 doses of PRP with an interval of 2 weeks in addition to the same exercise program. Initial evaluations of the patients will be made before the treatment and will be re-evaluated at the end of the 6th month.

Personal information with the Sociodemographic Data Form prepared by us; pain severity by Visual Analogue Scale (VAS); shoulder functionality will be evaluated with the Constant Murley Score, joint range of motion with the Universal Goniometer, muscle strength with the "Hand-held" dynamometer, and quality of life with the SF-36.

Statistical Analysis: SPSS (Statistical Package for Social Sciences) (SPSS 21.0) statistical program will be used in the statistical analysis of the data. Mann Whitney-U Test will be used to determine the difference between the efficacy of treatments. P < 0.05 will be considered statistically significant in all analyses.

56 patients who applied to the clinic with the complaint of shoulder pain between February 2022 and February 2023 and were diagnosed with Subacromial impingement syndrome by the investigative orthopedist according to predetermined valid criteria will be included in the study. After giving the necessary verbal and written information about the study, the patients with informed consent will be randomized and divided into 2 groups of 28 people. The cases will be randomly divided into groups and their treatment will be done by the same researchers. The evaluation will be carried out by another investigator blinded to which group the participants belong to before and after the treatment. After the initial evaluations are completed, the 1st group will be given a home exercise program that they will apply every day for 8 weeks, and the 2nd group will be given 2 doses of PRP with an interval of 2 weeks in addition to the same exercise program. Initial evaluations of the patients will be made before the treatment and will be re-evaluated at the end of the 6th month.

Patients who were diagnosed with subacromial impingement syndrome, between the ages of 45 and 65, without a history of shoulder injury other than subacromial impingement in the last 1 year and/or shoulder symptoms requiring treatment, who had not had any previous shoulder surgery and who agreed to participate in the study will be included in the study. Not meeting the inclusion criteria, a history of shoulder fracture, dislocation and/or cervical radiculopathy, presence of frozen shoulder, previous shoulder surgery, local corticosteroid injection/treatment to the shoulder joint in the last 3 months, presence of neuromuscular disease, pregnancy, history of cancer Patients with unstable angina, systemic inflammatory joint disease, conditions where exercise is contraindicated, orthopedic, rheumatic or congenital disease in the affected upper extremity, and communication problems will be excluded from the study.

The number of our volunteers was calculated with the "G power sample size calculator". In order to be able to determine at 80% power and 0.05 significance level, when the values of the first group are taken as 7.3±0.6 and the values of the second group as 6.9±0.5 using the initial and final pain scores according to the visual analag scale at a 95% confidence interval. At least 25 volunteers should be included in each group. Despite the possibility of the participants leaving the study, 3 people will be added to each group and a total of 56 volunteers will be included in the study. Consent will be obtained from the cases with a voluntary information form.

Inclusion Criteria:

• Diagnosed with subacromial impingement syndrome
• Between the ages of 45-65
• No history of shoulder injury other than subacromial impingement in the last 1 year and/or no shoulder symptoms requiring treatment
• Patients who have not had any shoulder surgery before and who agreed to participate in the study

Exclusion Criteria:

• Not meeting the inclusion criteria
• History of shoulder fracture, dislocation and/or cervical radiculopathy, presence of frozen shoulder, previous shoulder surgery
• Presence of neuromuscular disease who has received local corticosteroid injection/treatment to the shoulder joint in the last 3 months
• Pregnancy, history of cancer, unstable angina, systemic inflammatory joint disease, conditions where exercise is contraindicated, presence of orthopedic, rheumatic or congenital disease in the affected upper extremity
• Patients with communication problems will be excluded from the study.

Patients who were diagnosed with subacromial impingement syndrome, between the ages of 45 and 65, without a history of shoulder injury other than subacromial impingement in the last 1 year and/or shoulder symptoms requiring treatment, who had not had any previous shoulder surgery and who agreed to participate in the study will be included in the study. Not meeting the inclusion criteria, a history of shoulder fracture, dislocation and/or cervical radiculopathy, presence of frozen shoulder, previous shoulder surgery, local corticosteroid injection/treatment to the shoulder joint in the last 3 months, presence of neuromuscular disease, pregnancy, history of cancer Patients with unstable angina, systemic inflammatory joint disease, conditions where exercise is contraindicated, orthopedic, rheumatic or congenital disease in the affected upper extremity, and communication problems will be excluded from the study.