Ischial or ischiogluteal bursitis is a diagnosis referring to inflammation of the small flat, fluid-filled cushion called the ischiogluteal bursa that sits over the hamstring tendons at the sitting bone.
The hamstring muscles (semimembranosis, semitendinosis and biceps femoris muscles) in the back of the thigh help to extend the hip (take the thigh backwards), but also bend the knee. This combined function makes the hamstring muscles very important muscles for transferring forces between the hip and lower leg in actions such as running, kicking, lifting and lunging.
The hamstring muscles in the back of the thigh attach deep in the buttock, onto the sitting bones (ischial tuberosities). They attach onto the bone via elastic, fibrous tendons, together referred to as the proximal hamstring tendons. Proximal simply refers to the end of a structure closer to the head-end of your body.
Directly on top of the hamstring tendon attachments is a small flat, fluid-filled cushion (the ischial or ischiogluteal bursa) . This helps reduce friction and allows smooth gliding of the largest buttock muscle (gluteus maximus) over the hamstring tendons.
The bursa may be come aggravated due to many reasons. Ischial bursitis may be sudden, for example a fall directly onto one or both of your sitting bones. Alternatively onset can be gradual. This may occur, for example, due to prolonged periods sitting with pressure on the sitting bone, especially when the chair or surface you are sitting on is harder.
Read more in our Lower Buttock Pain page, under the Soft Tissue Related Pain tab.