The aim of this study is to evaluate the effects of low-level laser therapy (LLLT) and therapeutic ultrasound combined with home-based exercise in comparison with home-based exercise alone in patients with subacromial impingement syndrome (SIS). Participants are going to evaluate before training, and at the 1-month follow-up and 3-month follow-up using the visual analog scale (VAS) scores for pain during activity, at rest, and at night, and the Shoulder Pain and Disability Index (SPADI).

SIS is an important cause of pain and disability and affects activities of daily living. Therefore, a major goal of SIS treatment is to reduce pain and improve upper extremity function. In this prospective, randomized controlled, single-blind, interventional trial, a total of 60 patients with SIS who met the eligibility criteria are going to enrolled in the study. Eligible participants are going to randomly assign to one of the three groups by an independent blinded researcher, using a computer-generated random numbers and allocation ratio of 1:1:1: the LLLT group (LG, n = 20), the ultrasound therapy group (UG, n = 20), and the control group (CG, n = 20). Participants are going to evaluate before training, and at the 1-month follow-up and 3-month follow-up using the visual analog scale (VAS) scores for pain during activity, at rest, and at night, and the Shoulder Pain and Disability Index (SPADI).

Inclusion Criteria:

• Clinical diagnosis of subacromial impingement syndrome based on physical examinations
• Persistent pain in one shoulder for at least 2 months
• No passive shoulder range of motion limitations
• Failure of improvement in pain after analgesic medications

Exclusion Criteria:

• History of malignancy and systemic rheumatic diseases
• Evidence of systemic or local infection
• Presence of major trauma at the affected shoulder
• History of shoulder surgery
• Rotator cuff lesions in the form of either calcific tendinosis or full-thickness tear as confirmed on MRI scanning