The medial ligament, also known as the medial collateral ligament (MCL), is a key structure in the human knee. It is located on the inner side of the knee joint and connects the thigh bone, or femur, to the shin bone, or tibia. The MCL helps stabilize the knee by preventing excessive side-to-side movement. Injuries to the medial ligament can occur due to trauma or overuse, often resulting in pain and swelling. Treatment typically involves rest, ice, compression, and elevation (RICE), along with physical therapy to restore strength and flexibility. Severe injuries may require surgical intervention.