Subacromial Impingement Syndrome(SIS) is considered as one of the most common causes of shoulder pain, can be the source of considerable pain, disability and leads to limitations in activities of daily living.

This study aimed to investigate the effectiveness of the Pilates versus conventional treatment on shoulder pain, function, ROM and muscle strength in patients with SIS.

Shoulder pain is the third most common chronic pain among musculoskeletal disorders, following low back pain and knee pain; it is usually characterized as non-traumatic complaints that arise from arm, neck and shoulder regions.

Approximately 50% of those experiencing shoulder pain have symptoms that indicate subacromial impingement syndrome (SIS) diagnosis; the prognosis varies widely; from pain to limited range of motion affecting their daily life activities: with about 40% of individuals suffer from pain one year later after their initial consulting with their primary care clinician.

The SIS is a painful condition that characterized by narrowing of the subacromial space that causes inflammation and degeneration of rotator cuff structures, resulting in pain during arm elevating.

Previous research identified many causes for the impingement such as poor posture, overuse or repetitive trauma, age-related changes, fatigue of the scapular and glenohumeral muscles, biomechanical alterations, neuromuscular adaptations, rotator cuff and deltoid muscle imbalances.

It leads to pain, disability, limited range of motion (ROM), loss of muscle strength, poor quality of life and sleep disturbances. There are many treatment approaches adopted for SIS such as conservative, pharmaceutical and surgical approach in severe cases.

Regarding the conservative it is considered the main treatment of SIS it often includes therapeutic exercises such as scapular stabilization exercises, rotator cuff strengthening exercises, stretching exercises and Pilates exercise that are effective in restoring shoulder function.

Pilates exercise was developed by Joseph Pilates as a comprehensive exercise, emphasizes the connection between mind and body control, making it a valuable tool in rehabilitation for enhancing core muscle strength, endurance, flexibility, posture, ROM, overall health, and quality of life are prevalent for both healthy individuals and rehabilitation purposes for SIS.

Pilates has been shown to effectively reduce shoulder pain, improve ROM, enhance posture, and support functional recovery in individuals with chronic shoulder pain, as highlighted in studies emphasizing its role in core stability and movement control even though it has a favorable impacts, the evidence to demonstrate its effect is limited.

Inclusion Criteria:

• Male and female patients aged between 35-65 years old
• Presence of shoulder pain for at least three months
• Painful arc of movement during flexion or abduction or both
• The patient will be diagnosed with SIS if the tests of the Neer, Empty Can, and Hawkins will be positive during the physical examination.

Exclusion Criteria:

1. History of any surgical procedure to the affected upper extremity (Heron et al., 2017 and).
2. History of trauma, fracture, instability and shoulder dislocation to the shoulder in less than 12 weeks previously (EDA et al., 2016).
3. History of presence of cervical symptoms (neck pain, numbness or tingling in the upper extremity) (Heron et al., 2017).
4. History of corticosteroid injection in the shoulder region in the last 6 months (Turgut et al., 2017).
5. None- cooperative participants or cognitive impairment (a communication problem) (EDA et al., 2016).
6. History of any systemic illness, reflex sympathetic dystrophy and related syndromes e.g. rheumatoid arthritis, ankylosing spondylitis, diagnosed by physician (Heron et al., 2017 and Turgut et al., 2017).
7. Passive limitation of range of movement, stiff shoulder and less than 90 active elevation (Heron et al., 2017 and EDA et al., 2016).
8. Evidence of complete rotator cuff tear (positive drop arm test) (Heron et al., 2017).