Most of us have heard of people having ‘bursitis’, often of the hip or shoulder, but what is a bursa and why does it become painful and symptomatic? A bursa is a thin, self contained, lubricated cushion located at points of friction between a bone and surrounding soft tissue, such as skin, muscles, ligaments and tendons.
A bursa comprised of a synovial membrane containing and produces synovial fluid. Synovial fluid is a viscous fluid which plays an important role in lubricating joints and tissue in the body to decrease friction under load, assisting with efficient, pain free movement. The role of a bursa is to provide a low friction, slippery interface between two moving objects. Without them, movement would be painful as a result of the friction between the tissues.
Our body contains about 160 bursa, some quite superficial and some quite deep in the body. Bursa will vary considerably in size, depending on the individual and the location in the body. Traditionally, a painful bursa has been thought to be an inflammatory condition, resulting from excessive force and load to the bursa. While the mechanism for developing the condition is not disputed, there is now evidence of a lack of inflammatory cells in the condition and it appears that the bursa become thickened and loses its low friction gliding capability. The added bulk of the bursa also starts to impinge on movement, often within an already confined space..
The main mechanism for development of the condition is excessive repetitive load to the tissue, either through increased loading patterns or due to poor muscle control and movement patterns. Irritation to the Bursa may also develop as a result of trauma and the involvement of systemic inflammatory diseases such as rheumatoid arthritis may make the bursa more prone to development of the condition.
Common areas where the bursa become injured include the subacromial bursa of the shoulder. This condition tends to be common in overhead activities at work and in sport such as swimming, surfing and paddling. It is more prevalent in people with poor shoulder posture and weak scapular and rotator cuff muscles. The Trochanteric bursa on the outside of the hip is another common site of injury. It tends to be associated with poor hip stability as a result of weak gluteal muscles and is more common in women than men, though to be related to wider hips in the female population and increased angles of pull of the gluteal muscles.
Some less common sites of injury include the ischiogluteal bursa at the insertion of the hamstrings onto the pelvis, which is commonly seen in runners with poor technique, olecranon bursa at the back of the elbow from excessive leaning on the elbow (housemaids elbow) and supra patella bursa above the kneecap as a result of trauma or poor mechanics of the knee.
Treatment of an injured bursa by your physiotherapist will vary depending on the cause of the injury. In the event of traumatic injury or a sudden increase in loading patterns that will not continue, it is often enough to simply rest to de load the bursa and let the body do its thing this can often be helped with some stretch, tissue release, taping and possibly with a steroid injection into the area in stubborn cases.
As poor posture and muscle control are commonly significant contributors to the injury, in addition to the above approach, your physio will provide you with some strengthening exercises to restore appropriate mechanics in the affected area.
Article by Jim Burke