2. Muscle weakness
A weakening of the muscles around the kneecaps can be both a cause and a symptom of bursitis. The fact that that these muscles are strained may cause the bursae to be more vulnerable and more prone to inflammation and damage. In addition, a straining of the tendons in the form of tendonitis can also occur along with bursitis.
Sometimes the weakness in the muscles is not due to any damage done to the muscles but because of the pain in the general area. You may naturally feel less inclined to engage in physical activity and may feel fatigued as a result of discomfort with moving the area in general. It is a good idea to follow your instinct and to avoid moving too much if you feel you have bursitis, since straining the area can make the situation worse.