Background: Subacromial impingement syndrome (SIS) is a chronic and disabling disease, characterized by compression and mechanical abrasion of the tendons of the rotator cuff muscles, subacromial bursa and tendon of the long head of the biceps against the anterior surface of the acromion, coracoacromial ligament or the acromioclavicular joint during arm elevation movement. After the trauma, inflammatory processes initiate and may lead to loss of function when untreated. This inflammation leads the release of cytokines (IL-6, IL-10, IL-1β and TNF-α) whose acts as inflammatory mediators. Physical therapy works in treating SIS with the goal of reducing pain and inflammatory process. Cryotherapy is widely used in physical therapy by anti-inflammatory and analgesic effects, low cost, effectiveness and easy application. Objective: The aim of the study is to evaluate the effects of a cryotherapy protocol, applied on shoulder of subjects with SIS, on serum inflammatory mediators (cytokines) and local pressure pain threshold. Possible changes in function and pain will also be evaluated. Materials and Methods: 30 subjects will be selected and share in two groups, 15 healthy subjects and 15 subjects with SIS. Function assessments and quality of life will be held using the DASH and WORC questionnaires. Cryotherapy will be applied for 4 consecutive days, lasting 20 minutes without interruption through ice pack over the shoulder of SIS carriers. For the blood samples, 20ml of blood will be collected at the first and last day of the intervention, and then stored at -80 ° C.

Definition: The participants will be selected from population in general and will be screened by the inclusion and exclusion criteria below:

Inclusion Criteria:

• The diagnosis for SIS will be based on a clinical examination and self-reported orthopaedic history. at least 3 positive tests of: Neer impingement test, Hawkins impingement test, Jobe test, Speed test or Gerber test, pain with passive or isometric resisted shoulder lateral rotation, pain with active shoulder elevation and pain with palpation of rotator cuff tendons.

Exclusion Criteria:

• Fracture, osteoporosis, malignancy, infection, and active inflammatory process, pregnancy, systemic illnesses, physical therapy or manual therapy treatment within 6 months prior to the evaluation, signs of complete rotator cuff tear or acute inflammation, cervicothoracic spine-related symptoms (positive cervical compression test and excessive kyphosis), scoliosis, glenohumeral instability (positive apprehension, anterior drawer, or sulcus tests), or previous upper extremity fracture or shoulder surgery.