Leg locks are normally (but not exclusively) done when an opponent is prone or otherwise positioned on the ground. This is certainly the position from which the vast majority of leg locks are employed. Most leg locks that might be employed in a standing position will simply result in Nage, which often causes the lock to subsequently become ineffective.
Locks involving the leg typically deal with the knee, ankle, and hip joints. Some of these locks can be quite painful and care must be used when applying them on a training partner to prevent both injury and retribution when it is your turn to be Uke. You must therefore pay attention to tapping actions by your training partner. These can sometimes be harder to detect when you and your partner are both on the ground in contorted positions.
Another caution is that you may become accustomed to dealing with a training partner who is primarily motivated with ensuring you are applying your locks successfully. Therefore they will not react like an opponent. When applying locks to the legs it is essential that you find a way to restrain or restrict the movement of an opponent’s opposite leg and hands. Otherwise you could be busy employing a particularly painful lock only to receive a full-on Yoko Kekomi Geri just below the nose. Your dentist will look forward to your rewarding visit.
The legs have more restricted ranges of motion when compared with the arm. The typical range of motion for each leg joint is as follows:
- The knee joint is functionally similar to the elbow joint and has the following ranges of motion.
- The knee typically has a 0° range in Extension. In other words, the knee normally does not allow the lower leg to bend forward of the upper leg. Some individuals can move the joint in extension up to 10° or so.
- When bending the knee in Flexion, the knee can normally move through a range of from 0° to 135° (knee full bent).
- The knee can rotate internally only about 10°.
- The knee can rotate externally up to approximately 30°.
- The ankle has a fairly constricted range of motion when compared to the wrist.
- The ankle can move in flexion (bending the ankle so the toes move toward the front of the knee) about 45°.
- Moving the ankle in extension (moving the toes away from the front of the knee) has a normal range of up to 20°.
- Rotating the ankle in Pronation (moving the sole of the foot inward) allows for up to 30° of movement.
- Rotating the ankle in Supination (moving the sole of the foot outward) provides up to 20° of movement.
- The hip, like the shoulder joint, can be moved in many different ways.
- Bending the knee and pulling the knee up toward the abdomen allows up to 130° of flexion. This is the primary joint movement during Mae Geri.
- Moving the thigh back while holding the hips in place allows the leg to move back up to 30° in extension. Ushiro Geri depends on this movement.
- Similar to shoulder abduction, hip abduction involves moving the straightened leg directly outward (the kind of motion performed in a jumping jack). Generally the hips allow up to 50° of abduction. Some people can readily do the splits, which increases the abduction range well beyond 50°. This is, in part, used during Yoko Geri.
- Adduction can be thought of as the opposite of abduction. This movement allows the leg to cross the center line and move toward the opposite side of the body. Adduction normally has a limit of approximately 30°. This movement is prominently featured in Juji Dachi.
- Internal hip rotation is measured by standing erect and then bending the knee so the lower leg is parallel to the floor with the foot behind you. Keeping the thigh in a vertical orientation, move the foot outward and away from your center line. This motion is normally limited to a range of from 0° to 40°. Sanchin Dachi depends upon this movement.
- External hip rotation is measured using the same leg position used for internal hip rotation, except the foot is moved toward the opposite side of the body (crossing the center line). The hip will normally move in external rotation up to 45°. Kiba Dachi is enabled, in part, by this hip movement.
Ashi Kubi Kansetsu Waza (Ankle Locks)
Ankle locks often attempt to put the ankle joint in hyperflexion or hyperextension. Both are quite painful and potentially injurious. Additional discomfort can be generated by causing the foot to rotate in addition to moving into hyperflexion or hyperextension. Here are some examples of how ankle locks might be employed. See if you can find other potential locks using this joint.
- With both yourself and Uke seated and facing one another such that Uke’s feet are near your abdomen, take a mirror-side forearm and place it under Uke’s ankle just above the heel. Allow Uke’s foot to press into the back of your upper arm as you use your other hand to grasp your forearm that is under Uke’s ankle. Now press back with your upper arm into the top of Uke’s foot while pulling upward with your forearm at the base of Uke’s heel. You might amplify the effectiveness of this lock by pressing back into the foot using your core muscles. Altogether these motions place the ankle into varying degrees of hyperextension. Be careful because this locks does not provide you with subtle tactile feel so you may not notice when you are applying excessive pressure. This same lock can be applied if the opponent has fallen onto his or her back and you retain possession of a leg.
- If Uke is lying face down kneel down step between Uke’s legs such that your left leg is closest to Uke’s groin. Now kneel to lower your left shin onto Uke’s right thigh just above his or her knee. Use your right arm to scoop up Uke’s right ankle, causing Uke’s knee to flex nearly fully. Hook your right forearm over the top of Uke’s right foot and press the foot in the direction of Uke’s head. This is another form of ankle hyperextension. You might elect to move your right leg under Uke’s foot so that you can use your right hip to press Uke’s foot in the direction of Uke’s head as a way of ensuring Uke cannot escape.
- In a movement similar to the prior lock, lower your shin onto the back of Uke’s leg, but this time press your shin down into the lower calf of Uke’s leg rather than above the knee. You will want to ensure Uke’s foot is straight so the top of Uke’s foot rests on the floor (rather than the ball of his or her foot). Slight pressure will cause Uke’s foot to be moved into hyperflexion. This is a very dangerous lock that can result in broken bones, torn ligaments, and painful muscle tears. If you attempt this lock in practice you must ensure you are in a posture that will allow you to apply pressure very slowly and in a controlled manner. Go slowly and stop immediately when Uke even looks like he or she might tap out.
- If Uke is face down on the floor raise Uke’s foot while keeping his or her knee on the floor. Step over Uke’s leg such that your foot rests to the outside of Uke’s leg, but Uke’s foot is on the inside of your leg. Reach down with both hands to grasp Uke’s foot and rotate the foot into pronation. Pressing Uke’s calf into your leg will reduce the chances for Uke to escape.
Hiza Kansetsu Waza (Knee Locks)
There are a limited number of ways in which one might produce a knee lock. Some locks can be performed from a standing position, but these commonly result in the opponent falling, which may result in an escape or leg injury. The knee is a relatively strong joint, but if damaged it can result in severe disability issues. You must use caution when attempting to lock or manipulate a training partner’s knee.
Here is a short list of possible knee locks with which you should be familiar. Other knee locks performed while both you and Uke are on the ground will be discussed in your next belt.
- If someone kicks you with Mae Geri toward your torso area use your back hand to hook under the heel of the kicking leg, thereby trapping the leg in a nearly fully extended position. Quickly use your front arm to press down into the top of the opponent’s knee while pulling up with the back. This will, in most cases, straighten and lock the knee. This does not mean the opponent is helpless because they will usually be able to reach you with a hand. Since both of your hands are occupied you will not have an effective guard. You can, however, usually apply additional pressure to the knee and indirectly to the hip joint to destabilize your opponent, making a strike less likely.
- If the opponent has employed a Mawashi Geri to your torso instead of Mae Geri, a similar lock can be used but the initial preparation or setup is a little more involved. Use the arm on the side of your body that was kicked to trap the top of the opponent’s foot against your ribs. This is usually done by placing your forearm around the back of the opponent’s ankle and pulling inward tightly. Now use your opposite open hand to press into the opponent’s knee, turning the knee so it points directly upward. As the knee comes to a vertical position use your hand to press directly downward, locking the knee in position.
- When your hold a person’s ankle or lower leg during Nage in which the person falls backward, try to maintain control of the leg as the person falls. When the person has fallen, pull the heel of the opponent’s leg into your upper torso. Shift both hands so they press directly down into the knee while also stabilizing the knee so it cannot move. Rotate the person slightly so that they end up resting somewhat on the side of the opposite leg. This helps minimize the possibility of being kicked with that unattended leg.
It can be advantageous to rotate a person’s foot or ankle when applying a knee lock. This helps to keep the knee from bending and provides rotational stress on the knee. It does not take much pressure, so do not move too quickly when working with your Uke.
Experiment with other ways in which you can lock the knee straight while concurrently preventing the opponent from kicking or striking you. Think of pressing the knee against your leg in various ways. Also think of other ways in which your torso can be used to trap and assist with controlling an opponent’s leg such that the knee becomes locked.
Koshi Kansetsu Waza (Hip Locks)
Hip locks are hard to achieve and are not commonly practiced. There are so many other locks that are more easily accomplished that focusing on difficult to accomplish hip locks is largely irrelevant. However, there is a time and place for everything.
Hip locks are nearly impossible to accomplish without first producing a knee lock. If the knee can move then the hip can usually be moved, allowing an escape from a lock. With that in mind, there are two general ways to produce a standing hip lock, neither of which would be considered to be a sound lock.
- If the opponent has performed a Mae Geri trap his or her ankle with one arm and press into and lock the knee with the other hand. Now tilt the opponent’s entire leg upward and press the leg forward and into the opponent’s hip, locking the hip and rooting his or her pedestal leg. You will want to exercise good subtle control of the leg so the opponent cannot squirm out of the lock. But the lock will not last long; in all likelihood the opponent will fall. You might be able to continue employing the lock once the opponent is on the ground, but you will need to pay close attention to the opponent’s opposite leg, which is now free to kick you.
- You might trap an opponent’s leg between your arm and your torso if the opponent has delivered a Mawashi Geri in that region. By using your opposite arm to stabilize the opponent’s knee and preventing it from bending, you might lift the opponent’s leg and press it forward and down into his or her hip. Again this lock will probably only last a short period of time.
On the ground you will find hip locks to be only slightly more useful. Experiment with this locks because you never know when utilizing one can be useful. In reality however, you will seldom find a time and place where employing such a lock is the most useful and convenient option available. You will not be asked to demonstrate such a lock on a ranking examination, but that doesn’t mean you should not explore ways in which you might employ such locks. You just never know what will come your way in a conflict.