Bursitis is the swelling of the bursa, a small, fluid-filled sac that acts as a cushion between a bone and other moving parts, such as muscles, tendons, or skin.
The activities that are mentioned have repetitive motions and some high impacts in common.
Bursitis occurs when the bursa inflames. This can happen due to some activities using some joints for a prolonged time and with a lot of force. This bursa is essentially a sac that is filled with synovial fluid and it is located where there is direct contact between bones. This is there to reduce friction between some tendons or muscles and the bones in a joint. Cycling, long-distance running, and tennis are all high impact sports and really overuse some joints like the knees or wrists.
