Did you know your knee rotates axially in addition to the basics bending and straightening? If it doesn’t do this or if this is impacted either due to injury or pain, it can affect how well your knee bends and straightens. It also affects contact pressures with the knee cap (Patellofemoral joint). You NEEED full knee extension. Lacking it can affect the way you walk and be a contributor to a host of knee issues due to the less than ideal joint mechanics with loading. The research on tibial rotation & knee pain is interesting. We know that external rotation causes an increase in contact pressures and may be related to patellofemoral pain syndrome. Whereas, fixing the tibia in slightly more internal rotation, may decrease pressures on the pf joint. Rotational stability is also affected