The posterior cruciate ligament (PCL) is located in the back of the knee and helps to connect the thighbone to the shinbone, providing stability to the knee joint. A PCL injury can occur due to direct impact, hyperextension, or extreme twisting of the knee, causing pain, swelling, and instability in the knee joint. Treatment may involve rest, ice, compression, and elevation (RICE), physical therapy to restore range of motion and strength, and in some cases, surgery may be required to repair or reconstruct the damaged ligament.