Leg locks are commonly used in ground-fighting, certainly not against free attacks as a first choice. As with arm locks the object of all leg locks is to attack the joints in order to cause damage to the joint. One of the major problems of leg locks is that the weakest of the leg joints are still far stronger than the arm joints so as with many other techniques you have to have superior technique and balance. Putting locks on the leg is sometimes difficult due to the strength of the leg joints; however they can still be done very effectively.
Methods of applying locks to the leg are similar to those on the arm. The joints can be:
1. Twisted to rotate the joint out of its socket.
2. Crushed back on itself, usually with the attacker placing their own leg or ankle in the joint to provide leverage.
Ankle locks are similar to the wrist twist on the arm. They are used to twist the ankle sideways to damage the joint. The major problem of apply a lock to the ankle is that of keeping the attacker from rolling over and spinning out of the lock.
Pinning the attacker is difficult with an ankle lock and they still have their other leg free to kick with. Unless the attacker is forced onto their stomach and a lock applied which stops the attacker turning over or while the attacker is on their back and unable to turn over and cannot strike out with their free leg ankle locks have a limited use.
When looking at locks on the arm and leg it is usual to equate the knee joint with the elbow however, the method of applying locks to the knee is totally different than the elbow. The knee joint is simply too strong to apply locks by overextending the joint. Locks are usually applied in the same way as a wrist crush by driving the foot up to the back of the thigh. Because the knee normally bends this far it is necessary for the defender to place their leg in the joint in order to lever the knee apart. It is not possible to damage the knee unless the defender places their ankle or leg into the joint, the knee is simply too strong to damage any other way.
Pressure can be applied to the front of the knee to overextend the joint but usually requires the full weight of the defender’s body in order to be effective. This is usually done in order to get the attacker to the ground but is never used to restrain an attacker.
Locks to the hip are rarely used because the joint is so strong. The hip joint needs to rotate out of its socket in the same manner as the shoulder joint and this is difficult to do with the arms. The defender needs to use their legs in order to effect locks on the hip. Locks on the hip can really only be done with the attacker on their back which means that their free leg can be a danger to the defender, thus making locks on the hip not as safe as desirable for putting locks on.
Ashi Juji Gatame
Gyaku Ashi Garami
Gyaku Hiza Garami
Yoko Kubi Gatame
Straight Leg Lock
Bent Leg Lock
Bent Ankle Lock
Cross Leg Lock
Reverse Bent Leg Lock
Reverse Bent Knee Lock
Side Ankle Lock