What is bursitis?
A bursa is a closed fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body. "Bursae" is the plural form of "bursa." The major bursae are located adjacent to the tendons near the large joints, such as the shoulders, elbows, hips, and knees. When the bursa becomes inflamed, the condition is known as "bursitis."