Bursae

Bursae are small, fluid-filled sacs located around joints, acting as cushions between bones, tendons, and muscles. Their primary role is to reduce friction and allow smooth movement of tissues during joint activity. Bursae contain a small amount of lubricating fluid that helps prevent wear and irritation. Commonly affected bursae include those in the shoulders, elbows, hips, and knees. Inflammation of a bursa, called bursitis, can cause pain, swelling, and limited movement, often resulting from injury, overuse, or infection.