If you have a painful swollen bump on the back of your knee, towards the inside, you may have a Baker’s Cyst. This painful problem is often poorly managed, and many people are told that it will simply go away.
Baker’s Cysts are actually a bursitis of the bursa that sits under the medial hamstring muscle. Due to the bursa being swollen it starts to become pinched by hamstring contraction and knee bending instead of being a friction reliever, and this sustains the swelling.
While this can be from hamstring tightness, it is far more commonly due to swelling in the knee joint overflowing into the bursa, as these posterior knee bursae are continuous with the joint. Swelling in the knee can be caused by structural damage, such as osteoarthritis, meniscal tear, ligament damage, or (far more commonly) the humble Patellofemoral Joint syndrome.
In most cases of Baker’s cyst we find that correcting the patella tracking with some tape and exercise, and (paradoxically) icing the front of your knee (PFJ) instead of the back where the swelling seems to be is the solution to the problem. Simple!