A bursa provides cushion at the joint for bones, muscles, and tendons. Bursitis is often caused by overuse or repetitive actions. The structures around the bursa may become irritated. In turn, the bursa becomes inflamed. The shoulder, elbow, and hips joints are the most common spots for bursitis to occur. The spot may feel sore, achy, and stiff. The affected area may become swollen and more aggravated upon movement. Often times, the best way to solve the problem is rest. It gives your joint a much-needed break and can allow time for the inflammation to calm down.