Bursitis is an injury that may be associated with sporting activities or in occupations that require repetitive motions for long durations. It affects the bursa which is a sac filled with fluid inside a joint. The bursa is usually located in the joint between the bone and the tendon covering a muscle. A bursa is useful in the body because it acts as a shock absorber and protects the soft tissue from being damaged by the friction it may experience against the bone.
Everyone has hundreds of bursa in most parts of the body. A bursa can be thought of as a small zip lock bag containing oil inside without air. It makes movement between the tendon and the bone smooth and slippery. Without the bursa such movements would be quite painful.
Repetitive action causes friction between the bursa and the bone which may lead to inflammation of the sac. When this happens the person may experience pain and a swelling may occur around the affected joint. The most common sites for bursitis include the shoulder, knee, and elbow joints.
Excessive pressure over a long period of time may adversely affect the bursa. For example leaning on your elbow for a long time or engaging in activities that require frequent or repetitive bending of the elbow like in using a vacuum cleaner may cause elbow bursitis. Frequent pressure to one part of the body can also lead to irritation and inflammation of a bursa.
Traumatic injuries sustained from falls or car accidents may also result in bursitis. In such cases, a contusion might cause a swelling in the bursa leading to inflammation. An inflamed bursa will cause pain during normal movement activities.
Conditions that are characterized by systemic inflammations, for example rheumatoid arthritis may result in bursitis. Such conditions mostly affect people in the ages of 40 to 60 years.