The lateral ligament is a cord-like ligament on the outside of the knee and can be torn with skiing, or contact sports such as rugby and football. It can be badly damaged and thus you know there is a problem. However, it can become irritated and have a minor strain which is often poorly diagnosed as there are several other structures in this are.
The issues can be sharp and disabling pain in the outside of the knee when badly injured through to a more subtle soreness and irritation when twisting or running on the knee. There is a lot that we can do to first assess and properly diagnose your issue as well as treat it with numerous different treatments including manual therapies and exercise work.