Shoulder Subacromial Impingement

Shoulder subacromial impingement is the general term that describes non-traumatic pain that originates in the shoulder. This pain specifically occurs around the acromion of the shoulder. The acromion is a bony projection on the scapula that is connected to the clavicle near the shoulder joint. The acromion has multiple tissues that live underneath, which include the rotator cuff tendons (supraspinatus), the tendon of the long head of the biceps, a bursa (a fluid-filled sac that helps reduce friction during movement), and coracoacromial ligament. When the space beneath the acromion narrows, it can compress the surrounding tissues, resulting in increased stress, irritation, and inflammation.

This condition is commonly caused by repetitive overhead activities (commonly seen in occupations and sports), sudden injury, poor posture, or muscle imbalances including weakness of the rotator cuff and scapular stabilizer, tightness in the pecs, and overactivity of the upper traps. There could also be structural factors including bone spurs and acromion shape.

Common signs and symptoms include pain during overhead movements, weakness in the shoulder, reduced range of motion such as inability to reach behind the back, and difficulty sleeping on the affected side.

Early intervention is crucial to prevent the progression of this condition, reduce the risk of chronic complications, and minimize the likelihood of requiring surgery. Subacromial impingement is typically diagnosed through imaging studies such as radiographs or MRIs. However, physical therapists play a vital role in identifying this condition by utilizing specialized clinical examination techniques to educate patients and guide their understanding of their diagnosis.

Physical therapy is the typical method to treat subacromial impingement. Research has shown that physical therapy yields satisfactory results in 60% of patients undergoing conservative treatment within two years. Physical therapy can focus on strengthening the shoulder and back musculature, improving posture, and restoring the shoulder’s full range of motion through manual and stretching techniques.

Physical therapists are skilled at developing individualized treatment programs that can help with subacromial impingement. For an assessment and treatment choices, it is therefore advised that you speak with the physical therapist who is closest to you.

Written by Kennedy Hardemion, SPT

References

1. Diercks R, Bron C, Dorrestijn O, et al. Guideline for diagnosis and treatment of subacromial pain syndrome: a multidisciplinary review by the Dutch Orthopaedic Association. Acta Orthop. 2014;85(3):314-322. doi:10.3109/17453674.2014.920991

2. Subacromial pain syndrome. NHS inform. https://www.nhsinform.scot/illnesses-and-conditions/muscle-bone-and-joints/conditions/subacromial-pain syndrome/#:~:text=Subacromial%20pain%20syndrome%20is%20a. Accessed January 24, 2025.

3. Umer M, Qadir I, Azam M. Subacromial impingement syndrome. Orthop Rev (Pavia). 2012;4(2):e18. doi:10.4081/or.2012.e18.

4. Creech JA, Silver S. Shoulder impingement syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554518/#.

5. Escamilla RF, Hooks TR, Wilk KE. Optimal management of shoulder impingement syndrome. J Sports Med. 2014;5:13-24. doi:10.2147/OAJSM.S36646.