Tips on increasing knee extension after surgery. Advice summarized from our orthopaedic surgeon and physiotherapists. The top 3 exercises to perform to improve and regain the knee extension critical to full recovery after most types of knee surgery. Regaining full knee extension in the first few weeks following surgery is extremely important. After the 6 week mark it gets much more difficult to regain this range of motion. Full extension of your knee is critical in maintaining the long-term health of the tissues at your knee and to ensure you can continue to walk comfortably and safely. Patients who don’t regain full extension have more rapid degeneration of their knee and are more likely to have ongoing knee pain. Overall, they will be less satisfied with the recovery of their knee. Here are 3 tips to help you regain your knee extension quickly and safely. 1) Bridging 2) Quad sets and 3) Overpressure.