Jiu-jitsu is based on anatomical principles. As will have been noticed, the essential feature of the majority of holds and tricks lies in the forcing of a limb into an unusual position, and the placing upon the joints pressure in the direction contrary to that in which these are designed by nature to withstand any force. In other words, the joint is made to bend the wrong way - with disastrous consequences to the owner.
When one understands this principle, the exact method of performing the jiu-jitsu tricks will become easily apparent.
In Figs. 1 and 2 this principle is illustrated by means of a most simple example. The assailant's hand is bent at the wrist in a direction which nature did not intend, with the result that the person is forced, owing to the pain caused, to go to the ground. It is a trick that may be employed with great advantage should it ever happen that one is stopped by a tramp who makes a demand for one's purse. One temporises, one suggests that the demand will be complied with. The assailant will hold out a hand to receive the forced gift. His palm will be uppermost, as shown in Fig. I. With great quickness, the jiu-jitsuist seizes that outstretched hand with both hands in such a manner that her fingers are pressing on the palm and the lower part of the thumb, while her thumbs are upon the back of the hand just below the big knuckle of the second finger. The captured hand is then bent at the wrist forward and slightly sideways to the outside of the arm. So severe is the strain caused upon the wrist that the individual, unable to stand up against it, is forced over sideways to the ground in the manner illustrated (Fig..2). Taken by surprise, she can be thrown to the ground by the exercise of but comparatively slight strength; nor will she be given the opportunity of making effective use of her free hand.
Fig. 1 To render powerless a person with outstretched hand, seize the hand quickly with both hands, so that the fingers press on the palm and lower part of »he thumb, keeping your own thumbs upon the back of the opponent's hand below the knuckle of the second finger slightly sideways to the outside of the arm, so that she is forced
Fig. 2. Bending an opponent's wrist forcibly forward and sidewavs to the ground
The next trick is done by a grip of the wrist. It is a cross-arm hold - that is to say, the left hand takes a grip of the right. It is necessary that the hold should be taken from the outside of the wrist - that is, one's palm is placed on the back of the wrist. The captured hand is raised slightly, and a downward and outward twisting follows away to one's own left. The effect of this is to bring the erstwhile aggressor into the position shown in Fig. 3. The victim's elbow joint is thus locked, and when the right hand is brought upon her shoulder she will be quite unable to release her arm.
If the occasion arise, the arm can be broken at the elbow by a sharp blow with the right hand on the back of the limb; or the victim may be reduced to helplessness thus: press with the right hand on the shoulder, and she will be forced face downwards to the ground. The jiu-jitsuist should retain her grip on the left wrist, and by placing her foot or knee behind the shoulder, will be able to bend the arm backward in such manner as to hold the victim entirely helpless. While her arm is thus held, it will be impossible for her to get up (Fig. 4).
The arm-lock about to be described is one of the most effective defences ever discovered against an assailant armed with a stick, knife, or similar weapon. If it be the assailant's right hand that is armed, the wrist must be caught in its descent by the defender's left hand. An ordinary grip is taken, thumb pressing on the inside of the wrist, the edge of one's own hand uppermost (Fig. 5). The defender then forces the captured wrist back upon the upper-arm, assisting this movement by catching the aggressor's elbow with her right hand. An underneath hold of the elbow must be taken, and it will probably be found necessary to make a forward step with the right foot, preferably outside the opponent's right foot. The arm is now in the position for the lock to be fixed upon it. It is effected thus:
The jiu-jitsuist slips her right hand from the elbow under the aggressor's upper arm and upwards outside it, until she is able to place her fingers upon the bent-back hand or wrist (Fig. 6). The lock is now fixed, and it is impossible for the victim to release herself, no matter how strong she be. can she make use of the weapon with which she is armed. No great strength is required for the retention of the lock.
The aggressor may now be disarmed, the left hand being withdrawn for the purpose, for the peculiar position in which her limb is bent and held in position by the jiu-jitsuist's right hand causes such pain as to make it impossible for her to afford any satisfactory resistance. In most cases, however, it would be better for the defender to complete her work by throwing her adversary to the ground. This may be accomplished simply but effectively by a combined twist away to her own left, placing all her weight upon the captured arm. To make assurance doubly sure, however, it is recommended that one's is locked, so that, if necessary, her arm can be broken by & sharp blow with the right hand on the back of the limb right foot should be brought outside the assailant's right foot, which in all probability will be advanced, and the pressure against her leg, combined with the violent twist upon the curled-up arm, will bring her down forcibly without the slightest chance of escape.
Fig. 3. A cross-arm hold, by which the opponent's elbow ioint
It is not by any means asserted that a certain amount of strength is not necessary for the accomplishment of these tricks. Scientific as they are, some muscular power is requisite for their execution, but certainly not as much as might be expected. As said before, the chief point for their effective performance is quickness of execution, but when practising there must be no attempt to gain this quickness at the expense of accuracy. The average Woman has not the muscular strength of the average man, and any trial of actual strength between the pair is to be deprecated. It is never attempted by one acquainted with jiu-jitsu. Hence, there must be no effort at any time to force, by means of sheer strength, an assailant's hand or arm into the position required for the making of a lock. Swiftness of execution takes the place of strength, and the moves must be accomplished very quickly, otherwise the defender will give herself away by showing her hand. A slow, ponderous attempt to force an assailant's hand back upon his arm, as in the arm-lock just described, would be useless. Jiu-jitsu takes advantage of those moments when, an action being arrested, the muscles are temporarily relaxed and deprived of power. For the average woman, however expert a jiu-jitsu performer she might be, to attempt to force a strong man's arm into any required position would be ridiculous, and would certainly lead to failure.
Fig. 6. The further movement of the arm-lock, showing the lock fixed. The assailant is thus unable to use a weapon down helpless
Fig. 4. The trick shown in Fig. 3 can be used to force the victim to the ground, by pressing on her shoulder with the right hand. By placing the foot behind her shoulder, the victim can be held
Some jiu-jitsu tricks require considerable strength, therefore no mention of these has been made, and women are urged to give their time to, and concentrate their efforts upon, those tricks which require the minimum of strength backed up by the maximum of quickness of movement.
Assailant armed with a weapon. The wrist is caught in its descent
Fig. 5. An arm-lock that is a most effective defence against an and forced back upon the upper-arm