Restoring full extension of the knee following surgery can be difficult and frustrating for many patients. However, it is crucially important that full mobility is achieved early in the rehabilitation process. Patients who do not regain full knee extension are more likely to be dissatisfied with the outcome of their surgery and to experience ongoing pain and dysfunction.
You have about 6 weeks after your surgery where regaining knee extension is still reasonably easy. After the 6 week mark, it becomes progressively more difficult to remodel the tissues of your knee to allow for full range of motion.
There are two main reasons that patients have difficulty straightening their knee after surgery, even when the joint itself is not stopping motion. The first is hamstring spasm. The hamstrings are the muscles on the back of your leg that forcefully bend your knee and extend your hip. After surgery, these muscles tend to go into spasm, causing them to pull the knee into slight flexion.
After surgery the rectus femoris is usually still active, but the other quadricep muscles have a difficult time contracting.
Watch the following video to learn three exercises that you can do to get your quadriceps working again after knee surgery.
Getting your quads working properly can be a frustrating process. It will feel as though your leg is not listening to the signals your brain is sending. Stay with it. It will take a lot of repetition but the quadriceps will respond eventually.