# A Systematic Review on Low-Level Laser Therapy in the Management of Shoulder Impingement Syndrome
###### Abstract  
Background: Conservative therapy is currently the elective treatment for shoulder impingement syndrome according to the scientific literature. The success of conservative therapy is due to physiotherapy and the application of its methods. The aim of this systematic review was to evaluate low-level laser therapy, a physiotherapeutic method for pain reduction and increasing the range of motion. Methods: This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The screening of the literature was carried out on the Cochrane, PEDro, PubMed/Medline, and Scopus databases up until December 2021. All studies were randomized controlled trials (RCTs), and five articles met the inclusion criteria and were included in this study. The risk of bias was evaluated with PEDro and Jadad scales. Results: In this study, we reviewed five RCTs that compared low-level laser therapy with other physiotherapy treatments to reduce pain and improve range of motion in patients with shoulder impingement syndrome. Conclusions: Low-level laser therapy for shoulder impingement syndrome requires further investigation in future studies. shoulder impingement; low-level laser therapy; physiotherapy; systematic review +
Footnote †: journal: Medical  
lateral mid humerus [4]. A primary and a secondary form of SIS are described. The primary form of this syndrome is due to structural alterations that mechanically narrow the subacromial space. The secondary form results from a functional disturbance of humeral head centering [5]. Examples of primary shoulder impingement syndrome are those due to structural alteration of the anatomy of acromion, such as hooked class III acromion, curved class II, flat class I, or soft tissue swelling. Another case of shoulder impingement syndrome might show the normal anatomy at rest, with the starting of impingement during shoulder movements, probably secondary to rotator cuff weakness, which permits uncontrolled cranial translation of the humeral head. [PERSON] et Al. placed shoulder impingement into three categories based on stages of severity. In stage I, impingement is a consequence of edema, hemorrhage, or both, and it is classically seen with overuse-type mechanisms. Stage II shows greater fibrosis and tendon changes that are irreversible. A rupture or tear of a tendon may be the consequence of chronic fibrosis, and it is observed in stage III shoulder impingement syndrome [6]. Shoulder impingement syndrome is usually observed in individuals who engage in sports and activities requiring repetitive overhead activities, such as swimming, volleyball or handball; it also appears in people who work in manual jobs that require the prolonged overhead position of the upper limbs, such as builders, electricians or hairdressers [7]. Other extrinsic risk factors that may predispose individuals to SIS are bearing heavy loads, infections. and smoking [6]. This uncertainty about pathogenesis inevitably leads to confusion as regards the appropriate treatment; physiotherapy for SIS should be characterized by exercises for rotator cuff strengthening, with special attention on strengthening and retraining exercises for supraspinatus and infraspinatus rotator cuff muscles, and the trapezius and Serratus anterior to reduce scapular dyskinesia [8]. In recent studies, SIS was also defined as subacromial pain syndrome (SAPS) because of the lack of significant correlations between the acromiohumeral distance (AHD) and pain in adults with subacromial pain syndrome, and the importance of other biopsychosocial factors was underlined [9]. For many years, acromioplasty with bursectomy has been considered the gold standard for treatment of patients with SIS, but recently some researchers have questioned the need for surgery in this kind of condition, and consequently a more in-depth study of the pathogenesis has led to the publication of several papers investigating the benefits of decompression techniques used in surgery [6].