CPM machine exercise diagram CPM machine is the abbreviation of Continuous Passive Motion, the English name is Continuous Ppassive Motion, or CPM machine, also called knee function trainer. It is a device that helps to train the mobility of the knee joint and has been around since the 1970’s. It is useful for restoring the function of the knee joint after stiffness has occurred. It has played a very important role in the development of joint surgery for more than 40 years. However, as joint surgery concepts and techniques have advanced, experts have found that the CPM machine cannot be used for all patients with knee mobility disorders – there are indications for the application of this machine. Unfortunately, however, it is known that there are still a number of health care professionals who do not know how to use it properly, especially when it is applied to patients who have undergone artificial joint replacement, which not only does not help, but causes a lot of pain to the patient. I have even seen numerous nursing articles that talk about the “experience” and “benefits” of using a CPM machine after surgery, which is simply misleading! CPM machines for patients who have just undergone knee replacement or knee arthroplasty. When I tell them not to use it, some of them are very confused: is it wrong to help a patient exercise his or her joints? I often ask these doctors who don’t understand: Do you think the knee is stiff after a joint replacement? Some of them even answer me: “Yes, it’s stiff”! I laugh and cry and ask them: Don’t you move the patient’s knee well on the operating table? Did it stiffen up in a few days? If it was your knee that had surgery, would it hurt when you moved the joint yourself? The mechanism of CPM is to gradually “soften” a knee joint that is stiff and adherent by repeatedly and continuously flexing and extending the joint to achieve a normal level of motion. However, the joint is not really stiff after surgery and the patient is afraid to move the knee because the wound is painful and the patient is afraid to move the knee for fear of pain. At this point in time, the use of a machine to move the patient’s joint endlessly would add to the patient’s pain, so there is no point in using the machine for passive movement at all. To prevent adhesions in the wound (especially in the joint) after surgery, passive flexion and extension of the knee joint by the surgeon 1-2 times a day is sufficient, but the CPM machine keeps the patient’s injured leg moving, each time causing continued injury to the wound, resulting in bleeding, swelling and pain in the joint, which will seriously affect post-operative rehabilitation and joint function. Therefore, it is important not to use the CPM machine in the early days (at least 3 weeks or less) after the artificial knee replacement! The surgeon helps the patient to flex the knee on postoperative day 3 Active knee extension exercise on postoperative day 3