Pain when lifting your arm to the side or overhead, discomfort that wakes you at night when lying on the affected shoulder, and a sense of tightness or pinching in the top of the shoulder are classic signs of subacromial impingement. It is one of the most common shoulder complaints in adults and responds well to treatment when properly managed.
What is Subacromial Impingement?
The subacromial space is the narrow gap between the top of the humerus and the acromion, the bony projection of the shoulder blade that forms the roof of the shoulder. The rotator cuff tendons and a fluid-filled sac called the subacromial bursa pass through this space. Subacromial impingement occurs when these structures are compressed or pinched during shoulder movement, typically when lifting the arm, causing pain and inflammation.
The condition can result from a hooked or curved acromion shape, thickening of the bursa, bone spurs on the underside of the acromion, or muscle imbalances around the shoulder blade that alter the mechanics of the joint. In many patients, it is associated with a partial rotator cuff tear.
Types of Subacromial Impingement
Causes
A hooked or curved acromion shape narrows the subacromial space. Bone spurs on the underside of the acromion develop over time and progressively reduce the available space. Repetitive overhead activity in swimming, cricket, badminton, and occupational tasks such as painting or lifting narrows the space through bursal thickening. Poor scapular mechanics, particularly in athletes, can also contribute.
- Pain when lifting the arm sideways or forwards, typically in an arc between 60 and 120 degrees of elevation
- Shoulder pain at night, particularly when lying on the affected side
- Pain that is felt at the front or outer side of the shoulder and may radiate into the upper arm
- Stiffness and difficulty reaching overhead or behind the back
- Weakness in the shoulder, particularly with overhead tasks
Diagnosis
Clinical assessment includes the Neer impingement sign and Hawkins-Kennedy test, both of which reproduce pain by compressing the subacromial structures. X-rays assess the shape of the acromion and identify bone spurs. MRI provides detail on the rotator cuff tendons and the degree of bursal thickening, and is essential when a rotator cuff tear is suspected.
Treatment
Arthroscopic Subacromial Decompression
When subacromial impingement does not respond to physiotherapy, activity modification, and corticosteroid injections, Dr. Kushalappa performs arthroscopic subacromial decompression. Using keyhole incisions and an arthroscope, the inflamed bursa is removed, bone spurs are shaved down, and the undersurface of the acromion is reshaped to create more space for the rotator cuff tendons. The procedure is performed under general anaesthesia as a day case. Recovery involves a sling for comfort for 1 to 2 weeks, with physiotherapy beginning promptly. Most patients return to normal activities within 6 to 8 weeks and to sport within 3 months.
Why Choose Dr. Kushalappa Subbiah in Bangalore?
Dr. Kushalappa Subbiah completed a Fellowship in Shoulder Surgery at the Sydney Shoulder Research Institute, where he trained in advanced arthroscopic shoulder procedures including labral repair and reconstruction. He holds the International Olympic Committee (IOC) Diploma in Sports Medicine, and has direct clinical experience managing shoulder injuries in Indian athletes across cricket, swimming, tennis, and contact sports. He is appointed as a Consultant Shoulder Surgeon at NH Hospital, Bangalore.