Wednesday, October 31, 2012

Quadrupedal Jumps (part 1)

QM jumps must be considered from three perspectives:
  1. as a means of locomotion, jumping from hind to fore limbs like a rabbit or jumping from all four limbs like a frog,
  2. as a jumping technique to go over obstacles as quadrupeds do,
  3. as a safety mechanism in a failed bipedal jump, a hard landing or a landing on a slope.
QM jumps usually happen in frontal posture, and only exceptionally sideways or with the back to the ground. Both arms and legs are used in the impulse and in the landing, although the legs are preferrably used for jumping and the arms for landing. There is a moment where the body is fully detached from the ground, otherwise it is just a change of posture as described earlier. The simplest jump, from the feet to the hands, is just a grouping exercise done in "piqué" [ndt: with an explosive beat added to the move, a concept very central to George Hébert's works, but hard to translate accurately].

The teaching of QM jumps must indeed start with the grouping and extension exercises in frontal posture, moving simultaneously both hands or both feet. We can slowly increase the distance between where the hands and feet land, then start lifting the feet off just before landing on the hands. Finally, we can increase the width and height of the jump. During the entire time the body is airborne, the head must remain in extension.

We must distinguish two modes, corresponding to bipedal jumping modes:

  • the flexed jump, with the legs kept under the hips,
  • the extended jump, with the legs extending more or less straight from the trunk.
Only the extended jumps allow a great amplitude in height or length, but they are not feasible for beginners. A large amount of training is required in order to master them.

Exercises follow [ndt: more or less ordered by increasing difficulty, more to come in next post]:

  1. Forward jump: squat down with the hands on the ground in front of the feet, with the weight of the body on the legs. From this starting posture, throw the body forward by pushing on the legs strongly enough to lift the feet off the ground while bringing the arms forward. Extend more or less the body and land on both hands, arms flexed. Then, bring the feet close to the hands as in the starting posture. The body is ready for a new jump if needed.
  2. Backward jump: the execution of a backward jump is the opposite of that of a forward jump; the impulse comes from the arms and the landing is done on the feet. Squat down with the hands in front of the feet on the ground, the weight of the body being on the flexed arms. Then, without a pause, push back vigorously with the arms so as to extend the body backward, feet off the ground. Land on the feet after the hands have left the ground in order to execute a proper jump. As soon as the feet touch the ground, bring the hands closer to the feet to squat again in the starting posture.
  3. Sideways jump: the sideways jump consists in throwing the body sideways or at an angle, right or left, by moving successively the hands and the feet. It can be done in two ways:
    • jumping from the feet to the hands as in a forward jump, except that the hands and then the feet are placed sideways from the body.
    • jumping from the hands to the feet as in a backward jump, going sideways again.
    During the impulse, it is important to throw the body sideways and not straight. In the landing, one must resist the fall to avoid collapsing on one leg or one arm, as the landing limb on the side of the motion has a stronger shock to absorb.

Sunday, September 16, 2012

QM running exercises

Running in QM consists in using one of the previously described modes at variable running paces and modes, as in bipedal running. Depending on circumstances, one's training level and the exercise difficulty, a given mode of progression might be more or less adequate, thus a preferred mode is not always specified in the exercises. Training is performed in the frontal posture, which can be used to attain significant speed and can be sustained for some time. Some exercises can be performed with the back or the side to the ground over short distances, but it does not constitute proper running.
Exercises are as follows:
  1. Study of the following running modes: trot in simultaneous diagonal, trot in simultaneous same side, galop.
  2. Study of the hopping mode of running.
  3. Smooth transition between the different running modes. Inversely, sudden transitions from one to another.
  4. Special work of paces: slow, medium, fast with the different modes. Transitions smooth or sudden between paces.
  5. Racing in straight line.
  6. Race with sudden stop and go.
  7. Race with alternating backward and forward bursts.
  8. Race with a U-turn. The turn is done by stopping the anterior limbs and hopping with the hands or feet as pivot.
  9. Race with a full turn or two successive U-turns.
  10. Race with a sudden turn right or left.
  11. Race sideways like a crab, right or left, moving the limbs either by bringing them together or by crossing them.
  12. Race with curves and eight patterns.
  13. Race with a stop into one of the quadrupedal postures: squatting, kneeling, sitting, lying down front or back, etc.
  14. Race with long or high jumps.
  15. Race on three limbs, keping one hand or one foot always off the ground.
  16. Race with one arm and one leg, by little hops.
  17. Race in low posture, with arms and legs fully flexed.
  18. Race with unsynchronized limbs.
  19. Race on straight slopes up or down.
  20. Race on stairs up or down.

Monday, August 6, 2012

Quadrupedal Walk

QM walking consists in using one of the modes previously described (diagonal, side to side, galoping, hopping), trained at different paces either in active or passive mode as in bipedal walking. The training is mostly performed in frontal posture; the dorsal or side postures require smaller speed and amplitude, when at all possible. [Pilou's note: the following is a list of exercises more or less organized as a skill progression]
  1. Study the various walking modes.
  2. Transition between the different modes, either sudden or progressive.
  3. Work on the walking pace, from slow to fast, and the transitions between them.
  4. Walk in a straight line.
  5. Walk with sudden stops and starts.
  6. Walk alternatively forward and backward.
  7. Walk with U-turn left or right. The U-turn can use the arm or the leg as pivot.
  8. Walk with 360 degrees turns.
  9. Walk with hook turns right or left, changing direction by 90 degrees or less suddenly.
  10. Walk sideways or like a crab.
  11. Walk following curves or a figure 8.
  12. Walk with a stop in any of the static QM posture: squatting, kneeling, sitting, in plank, etc.
  13. Walk with long strides in length or in height.
  14. Walk on three limbs, keeping an arm or a leg always above the ground.
  15. Walk with one arm and the opposite leg.
  16. Walk with additional contact of the knees (frontal posture) or the hips (dorsal posture). In frontal posture, bring the knee on the ground just after the foot; in dorsal posture sit on the butt between the step with the hands and with the feet. This kind of walk is useful to provide a rest, to move on slanted ground or without an arm, and to move while pushing an object.
  17. Walk with one or both forearms. On slopes or to provide some rest, one can use the forearms instead of the hands as a basis.
  18. Low walk: the limbs are flexed in order to bring the body closest to but off the ground. In such case the speed is very limited and the move tiring, so it should be kept for small distances and can be made easier by using knees or forearms.
  19. Walks where both pairs of limbs work separately, for instance moving the hands one after the other then the feet, etc.
  20. Walk on slopes.
  21. Walk on stairs.

Sunday, July 22, 2012

Advantages of QM jumps for locomotion

In all types of QM progression, the arms have to provide more and more efforts when increasing speed, both in cushionning the impact with the ground and in pushing away in the next step. When moving in diagonal or galopping, a single arm has to work with the help of a leg or even alone, limiting the maximum achievable speed by the maximum power of the arm.

When jumping, however, the arms are not a major limitation for speed, and this mode of locomotion also favors speed for the following reasons:

  • the arms always work together, making their power the highest possible (roughly twice that of other modes). In addition, their role is only to absorb impact during landing; they are not needed to provide any impulse.
  • the impulse is produced instead by both legs together, which allow them to provide all their power with a full extension.
  • the movment is less tiring on the hip area because of the succession of grouping and ungrouping of the body.
  • finally, the alternating rest of anterior and posterior limbs is improved. [ndt: it is not entirely clear if this means the limbs are allowed to rest better or if their posture on the ground is more stable. Both might be relevant.]
The jumping walk or run, like a rabbit or a dog, constitutes for humans the most powerful and fastest means of OM locomotion, particularly if the quadrupedist can perform a full extension of the body at the end of each impulse.

In galopping, one of the impulses is made with a diagonal with one arm and the other arm works alone, having a very violent contact with the ground. The attainable speed depends on the resistance capacity of that arm; subjects with strong arms may reach their maximum speed with galopping as well as with jumping, although galopping is more tiring after a certain distance because of the fall on a single leg at the end of the move.

In summary, jumping or hopping is the fastest and least tiring QM mode for most subjects. Only a certain body conformation and large amounts of flexibility can make galopping faster. This preference to imitate hopping quadrupeds is largely due to the flexibility and ease of movement of the posterior limbs, and the limited effort required of the anterior limbs. At full running speeds, a trained quadrupedist can bring the feet to land forward of where the hands hold, making long individual jumps that can exceed two meters [ndt: 2m = 6 feet].

Sunday, June 24, 2012

Modes & paces of locomotion

QM locomotion modes differ with the way the limbs are moving:
  • in diagonal, moving successively diagonally opposed limbs in four steps: left leg, right arm, right leg, left arm.
  • in synchronized diagonal, moving simultaenously the limbs in two steps: left leg and right arm, then right leg and left arm.
  • in sides, moving limbs of the same side together in four steps: right leg, right arm, left leg left arm.
  • hopping, i.e. moving the same type of limbs together in two steps: both arms, then both legs.
  • galopping, which imitates the faster pace of most quadrupeds. The move is made of three steps: one leg, then one diagonal, then one arm.The same arm always goes in front, and there are two symmetrical galops: right-sided, where the right arm is always in front and the three steps are left leg, diagonal (right leg and left arm), right arm; left-sided, where the left arm is always in front and the steps are right leg, diagonal, left arm. The rhythm of these steps is not the same: the leg takes a longer step followed by two quick steps of the diagonal and the arm. This is because the first step of a galop is composed of two efforts: first to support the weight of the body at the end of the previous move, then to provide an impulse strating the new move. This is why that leg tires most rapidly.
Most animals only use certain modes in walking and others in running. Humans can use any of them walking or running, however the different modes have better or worse efficiency at different paces. Even for a more natural running mode such as the galop, it is good to learn first the walking version to better master the running one.

Monday, May 21, 2012

Quadrilocomotion

After the QM postures, we now turn to QM locomotion. As in bipedal locomotion, there are three main modes of displacement: walking, running and jumping. Although a single jump is a short and intense movement, as a series of horizontal jumps it becomes a remarkable mode of progression.

In QM, the movement is determined by the action of a single limb or of two limbs together: either arm and leg in diagonal, arm and leg on the same side, or as a "biped", i.e. both arms or legs together.

Walking consists in progressing by moving the limbs one or two at a time, while at least two of the limbs remain always in contact with the ground. The step as defined by the displacement of feet and hands separately or in relation to each other is the same when the walk is well coordinated.

Running consists in progressing by moving one or two limbs as in walking, but when running there is only one limb or biped in contact with the ground. There is no stable posture of the body between movements: running is really a series of small hops or jumps of regular amplitude.

Jumping consists in moving upward in the air either as a displacement or to go over a real obstacle, executed in length, in height or in depth. The jump up usually relies on the posterior limbs, while the landing uses the anterior limbs, sometimes both.

To these three principal modes we must add some secondary progressions in grouped or squatting posture, and a mode of progression with the body flat on the ground which deserves its own study: crawling.

QM locomotion can be executed in ventral, dorsal or lateral body posture, however the ventral posture is the most efficient and useful, thus the following descriptions will focus on the ventral posture.

It is of interest to note that human beings, once turned into quadrupeds, can use the modes of locomotion of various animals and even progress in dorsal or lateral posture, whereas the animals of a given species only practice the modes of progression they are naturally built for.

Although the quadrupedal locomotion is only an occasional mode of displacement compared to bipedal locomotion, it can be essential in practical situations (especially in defense and hiding against danger) as a short and fast move or as a long and slow one. It is necessary to practice its technique and build up the strength it requires to make it a natural ability. Finally, it is also an excellent exercise for developing the muscular system as a whole and increasing joint flexibility, yet another good reason to practice it.

Monday, May 14, 2012

Hand presses

Hand pressing consists in, from any QM squatting position, an effort of the arms in order to detach entirely the feet from the ground. It is a useful move to throw the body quickly forward, back or sideways or to get back on one's feet after a hold or a fall on the forelimbs. It requires a full development of the arms and torso and a great pressing power. To press in forward position, one starts with the hands behind the feet, sitting on the ground. Then the legs are taken up by pressing the arms down, and the legs and torso can be raised in various postures. For the backward position, one starts squatting down with the hands in front of and close to the feet. The arms start half or quarter flexed, to bring the shoulders forward of the hands. Keep at the same time the head in extension. Then, the body can be raised onto the arms by rotating the torso and grouping the legs in. The relative position of hands and shoulder must be adjusted to maintain balance, and the head should be kept extended. One can make the move easier by placing the knees out onto the arms or by pressing the head down from the start. The sideways press can be done similarly, either from a forward or backward starting position, and then leaning sideways. One can also squat with the hands forward and to the side, and raise the legs behind and sideways. One can also train the transition between forward and backward press, which is done by rotating the torso around the shoulders, moving the legs between the arms, and going back up in the other position. Finally, for the handstand press, we start squatting with the hands in front of the feet. Start like a backward press then, once the body is well balanced on the arms, extend progressively the legs up while extending the back at the hips. The balance of the body on the arms is essential to success. As in the backward press, the shoulders must start forward of the hands, arms partly flexed. During the upward rotation of the body, balance is maintained by the extension of the lower back and hips, minute changes in shoulders, arms and head posture, and small movements of the fingers. The extension upward can go toward a full stand, in which case the arms are straightened. To come back from the press, one can simply let the legs fall back down, flexed, making sure to bring the feet close to the hands (there are also other, more dynamic techniques explained later on). The handstand press as described here is done "in strength", without momentum, and should only be attempted after mastering a regular handstand. It is also important to know all the proper falls in case of a loss of balance. The press without momentum can be made easier by starting in forward press and swinging the legs between the arms to go up.