 Hello, I'm Dr. Sunil Kini, consultant joint replacement and arthroscopy surgeon at Manipal Hospital's Bangalore. To start with, there are four important ligaments in the knee joint. One in the front and back, which we call as the anterior cruciate ligament or ACL. One in the behind is called the posterior cruciate ligament or the PCL. There are also side-supporting ligaments on either side of the knee. One on the inside is called the medial collateral ligament or the MCL. And the one on the outside of the knee is called the lateral collateral ligament or the LCL. So, the physiotherapy for various kinds of these ligament injury and post-surgery is slightly different. So, I'd like to mention about the more common injury in about 80 to 90% of the cases, which is the ACL or the anterior cruciate ligament injury. So, once the surgery is done, it's important to start with the physiotherapy as soon as possible. The physiotherapy after an ACL surgery continues for up to nine months after surgery at the point of time at which the patient can start sporting activities also. The knee ligament ACL surgery immediately after surgery, the patient has to be on a brace, what we call. For the first two weeks, it's going to be a straight knee brace. And after that, after a stitched removal for the next four weeks, we usually put the patient on what we call as the hinge knee brace in which the patient can actually bend the knee by himself or herself. The other exercises which we strengthen upon immediately the day after surgery is the static quadriceps exercises or also what we call as the thigh-squeezed exercises. We also start about heel slides, hamstring exercises, assisted or passive knee bending and knee straightening exercises as well. Immediately after surgery, the patient is expected to have some amount of pain and will be using a crutch or a walking stick say for about the first week after which it can be slowly discarded. During the second and third week, it's also important to continue with the physio. The initial goals of physio is to get back the knee range of motion and secondly is to reduce the pain and swelling and also thirdly is to strengthen the muscles around the knee. After the first couple of weeks, we start the patient as I previously said on a hinged knee brace in which the patient can bend himself. So after six weeks, usually the brace is discarded. The other set of exercises which I said the open chain exercises are next started in which the patient is encouraged to do also do a stationary bike as well at the end of six weeks which continues up to three months. So there's various sets of exercises which we divide as the first two weeks after surgery, two to six weeks at three months, six months and nine months. So at the end of nine months, patient would have a pain-free range of motion in the joint as well as the strength needed to carry on with the sporting activities as well. It's also important to emphasize here that after an ACL reconstruction in which we put a new ligament into the knee joint, the first six weeks to three months is the time limit at which the graft which we put in is at its weakest. So after three months, the graft has attained a reasonable amount of strength after which certain exercises can be or certain activities can be carried on.