A bursa is a sack of fluid that helps to protect areas from pressure and friction. However, if there is increased pressure or load to a bursa, it can become inflamed, hence bursitis.
There is a bursa present over the outside of the hip bone which can get irritated by the overlying muscle during exercise / activity and this is termed trochanteric bursitis.
Often, this requires a standard rehabilitation programme although in some cases; a detailed 3D gait analysis is required to diagnose any underlying problems with function and help to target the rehabilitation programme.
An MRI scan is sometimes required for diagnosis and a guided steroid injection can be effective in reducing symptoms although any underlying dysfunction still requires addressing.