Lateral collateral ligament (LCL) sprain occurs when the ligament on the outer side of the knee is overstretched. The lateral collateral ligament is a thick, strong band of tissue that connects the thighbone to the shinbone. It is located on the outer side of the knee. It helps keep the knee joint stable. It is one of several collateral ligaments that support the knee. The LCL can be injured if the knee is hit on the inner side, which pushes the knee outward, or if the knee straightens too quickly or forcefully (hyperextends), which causes stress on the outer side of the knee. The LCL may be stretched, partially torn, or completely torn. The pain of a LCL injury may cause you to limp.
With an injured LCL, you may feel: