Tendonitis is when a tendon gets inflamed and can be another source of pain in the shoulder. Many different problems can cause inflammation of the bursa or tendons. Impingement syndrome is one of those problems. The rotator cuff connects the humerus to the scapula. Tendons attach muscles to bones.
Muscles move the bones by pulling on the tendons.
The rotator cuff helps raise and rotate the arm. As the arm is raised, the rotator cuff also keeps the humerus tightly in the socket of the scapula . The upper part of the scapula that makes up the roof of the shoulder is called the acromion. A bursa is located between the acromion and the rotator cuff tendons. A bursa is a lubricated sac of tissue that cuts down on the friction between two moving parts.