The four muscles that raise and lower the arm (and their respective tendons) are collectively known as the rotator cuff. The rotator cuff lies under the roof of the shoulder (an extension of the shoulder blade known as the acromion). The space between the acromion and the rotator cuff tendons is filled by the subacromial bursa. This bursa is a fluid filled sac that allows for smooth gliding of the rotator cuff under the acromion with overhead movements of the shoulder.
Treatment of impingement syndrome involves:
The operation aims to increase the size of the subacromial area and reduce the pressure on the muscle. It involves cutting the ligament and shaving away the bone spur on the acromion bone. This allows the muscle to heal.