In Locks we often focus on the elbow or the wrist. Only sometimes as a type of extra we get into leglocks. Remember that if you fight on the floor or catch a kick you might win a fight almost immediately through administrating leglocks.

The main goal with a leglock is to create a sprain in the ligaments or dislocate the joint of the knee or the ankle.

This is the optimal link:

http://judoinfo.com/leglocks.htm