I am confused about knee mobilization. I thought that the patella moves inferiorly with knee flexion and superiorly with knee extension. Therefore, how would a superior glide of patella promote terminal knee extension? I thought you always go in the opposite direction. For example, to improve ankle dorsiflexion we do talocrural posterior glide. Is the patella just an exception? Thanks.

The concave/convex rule applicable to the articulating ends of bones of a referenced joint typically determines the direction of mobilization or glide of the bones of that joint. To mobilize a joint where the movable bone has a convex articulating end, i.e. it articulates with another bone with a concave articulating surface, mobilization usually occurs in the opposite direction of normal bone motion. The converse is true for bones with concave articulating surfaces i.e. mobilization occurs in the same direction of normal bone motion. In other words, mobilization does not ALWAYS go in the opposite direction.

The articulating surface of the patella is concave, hence a superior glide would promote terminal knee extension.

The popular review books list the articulating bones of the major joints of the body in terms of their concavity or convexity and in which direction mobilizations/glides typically occur (I say ‘typically’ because there are indeed a few exceptions to the concave/convex rule. However, the patella interaction isn’t one of them).

Reference 1