Pes anserine bursitis is an irritation or inflammation of a bursa in your knee. A bursa is a fluid-filled sac that acts as a cushion between tendons, bones, and skin.
The pes anserine bursa is located on the inner side of the knee just below the knee joint. Tendons of three muscles attach to the shin bone (tibia) over this bursa. These muscles act to bend the knee, bring the knees together, and cross the legs.
Pes anserine bursitis is common in swimmers who do the breaststroke and is sometimes called breaststroker's knee.
Pes anserine bursitis can result from:
Pes anserine bursitis causes pain on the inner side of the knee, just below the joint. You may have pain when you bend or straighten your leg.
Your health care provider examines your knee for tenderness over the pes anserine bursa.
Treatment may include:
The goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your injury, which could lead to prolonged symptoms. Everyone recovers from injury at a different rate. Return to your sport or activity will be determined by how soon your knee recovers, not by how many days or weeks it has been since your injury occurred. In general, the longer you have symptoms before you start treatment, the longer it will take to get better.
You may safely return to your sport or activity when, starting from the top of the list and progressing to the end, each of the following is true:
Pes anserine bursitis is best prevented by a proper warm-up that includes stretching of the hamstring muscles, the inner thigh muscles, and the top thigh muscles. Gradually increasing your activity level, rather than doing everything at once, will also help prevent its development.