Arm locks are those locks which attack the wrist, elbow and shoulder locks. The preference is to operate on the joints which are weaker and progress, if necessary to those that are stronger. The wrist joint is much weaker than the shoulder joint.
The finger joints are the weakest of all joints but are not considered practical for defences against free attacks. Usually in free attacks the fingers are either curled into a fist or are wrapped around a weapon and are very hard to grasp while on the move. Once the attacker has been grasped, or resists an arm lock, it is then possible to get at the fingers to apply a lock to them.
Wrist locks are those locks which act primarily on the wrist joint. The wrist joint can be twisted or crushed in three directions.
- The hand can be twisted around an axis running through the middle finger and down the palm
- The palm of the hand can be crushed onto the inside of the forearm, thus overextending the wrist joint.
- Twisting the hand, when bent at an angle of 90° to the forearm, around an axis running through the forearm.
Each lock can have a number of variations but the primary method of twisting, or crushing the joint is maintained in all the variations.
Locks on the elbow can be done in two ways.
- By overextending the elbow joint by forcing down on the joint.
- By twisting the radius and ulna around each other to dislocate the ulna joint from the elbow. This method is unusual in that most people feel the lock in the wrist joint before the elbow, however, the elbow is the joint which is damaged if the lock is taken to its fullest extent.
Shoulder locks act on the shoulder joint by rotating the shoulder joint out of its socket in order to dislocate the lock. All variations of the shoulder joint rely on this method of dislocating the shoulder joint.
Yoko Tekubi Hishigi
Ushiro Ude Garami
Straight Arm Lock
Bent Arm Lock
Side Wrist Crush
Rear Bent Arm Lock