Description

Subacromial impingement syndrome (SAIS) is one of the most frequently encountered musculoskeletal disorders, affecting approximately 20-30% of the general population and representing a major cause of shoulder pain. SAIS has been associated with altered scapular kinematics, rotator cuff muscle imbalance, soft-tissue tightness, postural abnormalities, and impaired neuromuscular control. Conventional physiotherapy-including therapeutic exercises, stretching, electrotherapy modalities, and manual techniques-is commonly used in clinical practice. However, evidence suggests that combining manual or soft-tissue-based interventions with standard physiotherapy may yield more effective improvements in pain, mobility, and shoulder function.

Instrument-assisted soft tissue mobilization (IASTM) is a manual therapy technique that uses ergonomically designed stainless steel tools to provide controlled mechanical stimulation to soft tissues. IASTM has recently gained attention due to its ability to increase soft-tissue extensibility, promote myofascial release, and enhance joint range of motion. Similarly, vibration-based interventions-including percussion massage therapy-have been shown to improve circulation, decrease pain, reduce muscle stiffness, and enhance mobility through mechanical oscillation and stimulation of sensory receptors. Despite their growing popularity, limited evidence exists regarding the direct comparison of vibration therapy and IASTM in individuals with SAIS.

This randomized controlled trial aims to evaluate whether adding vibration therapy or IASTM to conventional physiotherapy provides superior outcomes compared with conventional physiotherapy alone. A total of 48 adults aged 40-60 years with MRI-confirmed SAIS will be randomly allocated into three groups: (1) Vibration Therapy + Conventional Physiotherapy, (2) IASTM + Conventional Physiotherapy, and (3) Conventional Physiotherapy (Control). All interventions will be delivered three times per week for four weeks. Vibration therapy will be applied using a percussion massage device (33 Hz) to the deltoid and rotator cuff muscles along the origin-to-insertion path. IASTM will be applied using standardized sweep and brush techniques at a 45° angle to both anterior and posterior shoulder muscle groups. The control group will receive conventional physiotherapy consisting of ultrasound, TENS, cryotherapy, passive stretching, Codman exercises, wand exercises, finger ladder exercises, and progressive strengthening, supervised by a physiotherapist.

Outcome measures include pain intensity (VAS), shoulder range of motion measured with the Goniometer Pro mobile application, proprioception assessed at 60° flexion and abduction, functional disability evaluated using the DASH questionnaire, and shoulder-related quality of life measured with the RC-QoL scale. Assessments will be conducted at baseline and after the 4-week intervention period.

This study seeks to contribute to the current literature by directly comparing two frequently used soft-tissue interventions-vibration therapy and IASTM-within the SAIS population. The findings are expected to inform clinicians about the potential added benefits of combining these modalities with conventional physiotherapy to optimize pain reduction, functional improvement, and neuromuscular outcomes in individuals with subacromial impingement syndrome.