Typically the LCL is injured when there is direct force on the inside of the knee - the part closest to your other leg. This can cause the LCL, which is located on the outside of the knee, to be stretch or torn beyond its normal range of motion. Tears to the LCL are often seen during knee dislocations. Luckily LCL injuries are far less common than tears to other ligaments in the knee.
The symptoms of an LCL injury are similar to other ligament injuries. You may experience pain and tenderness along the outside of the knee, along with swelling. Some people also describe a feeling of instability in their knee when walking, as if the knee may give out, lock or catch. Your knee may feel stiff and be swollen. To confirm the diagnosis of an LCL injury, consult your physician. He or she will be be able to assess your knee in person and check on the range of motion. They may also ask you questions to help diagnose your injury.