A cruciate ligament sprain is an injury caused by overstretching or tearing of one or more of the cruciate ligaments of the knee. There are two cruciate ligaments in the knee – the anterior (lateral) and the posterior (medial). A sprain of the cruciate ligament may be signified by a popping sound at the outset followed by pain and swelling. Longer term effects (even after the individual has resumed walking) include knee instability and a feeling that the knee is “giving out”. Certain orthopedic braces like the ones below are designed to immobilize the structures of the knee to promote more rapid healing, as well as to reduce knee instability. To ensure that the brace you choose is suited to your particular injury as well as your activity level, you should consult with your doctor before making a choice.