Diagonal Advanced Placement (DAP) in dressage horses

Discussion in 'Horse Training' started by StraightandTrue, Jan 7, 2018.

  1. StraightandTrue

    StraightandTrue Senior Member

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    Every dressage rider learns that if the front leg hits the ground first then the horse is on the forehand. Horses that are naturally built uphill are seen as having an advantage. Their conformation makes it easier for their hind legs to hit the ground first - something that is referred to as Diagonal Advanced Placement (or DAP).

    But I've been seeing more and more photos of top dressage horses where the hind leg pushes off before the front leg does in trot, which is apparently a side effect of DAP. It looks to me like the horse is balancing over it's front leg at the end of the stride, and is pushing off the front leg too. Does the fact that they're weighted over the front leg mean the horse is actually on the forehand, despite the appearance of collection? Or am I interpreting the biomechanics of this action incorrectly? I'd love to hear what other dressage riders/trainers have to say.

    Image below to show what I'm talking about. The offside fore is still in contact with the ground, whereas the nearside hind has already left the ground. Note: this post is not targeted at any particular rider, the image I've chosen is purely to illustrate what I'm referring to.

    [​IMG]
     
  2. slc

    slc Senior Member

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    I'm sorry, but you're incorrect, though it is a very common mistake when photos are excessively dissected, and good to bring out and discuss. However, it's not quick or easy to explain so the impatient should skip this.

    The offside fore here, is not bearing weight and is not in contact with the ground in any meaningful or significant way. The horse is simply so relaxed that that the toe just hangs down a bit as the leg travels back. This is due to relaxation that starts in the shoulder and is correct and desirable.

    There is much good going on in this picture. It's important when observing horses and riders, to be able to see the positives that are going on and not just 'fault hunt.' The rider's shoulders are back a bit too much, but the horse's back is lifted and while the horse looks very much the 'Type A personality', he's moving quite well.

    In this picture, the left front foot is reaching forward and is slightly higher in the air than the diagonal hind leg. This is due to lightening of the forehand and is correct.

    Is the photo showing DAP? Maybe but you can't prove that with still pictures. The hind legs do have an energetic 'forward driving' look to them, so maybe. But to see DAP, you need to see the entire flight pattern of the hind feet and front feet, from their most rearward position all the way to the furthest forward reach. In other words you need to look at a high speed video. You can't evaluate DAP in a still photo.

    DAP - Diagonal advanced placement - is something Swedish researchers discovered many years ago in unbroken saddle horses that were deemed to move especially well. This only shows momentarily, and only on high speed film, and cannot be perceived with the naked eye.

    If an alteration in the trot rhythm IS perceivable with the naked eye, if the two-beat trot breaks down to the point where there are four hear-able or visible beats, it is not DAP. In that case the trot is 'disunited'.

    The usual way the trot becomes 'disunited' is fairly minor and common, but hard for novices to feel or see - in that the forelegs move more quickly than the hind legs during a part of the stride. This isn't so rare, especially in green horses when they are ridden incorrectly or are starting to tire. It doesn't usually rise to the level of the two beat rhythm being lost. But when this issue happens the rider is admonished to use his half halt and driving aids (legs) to 'Quicker the hind legs!'(often shouted at clinics and in lessons with more knowledgeable trainers), and encourage the horse to move his legs with energy - or dismount.

    In DAP, at one point in the stride the hind feet are momentarily, infinitesimally 'ahead' of the foreleg, but still land and connect with the ground at the same time as the foreleg. With DAP, there is no actual change to the 'unity' or 'purity'(2 beat) of the trot.

    Many people try to post pictures online showing their own horses displaying DAP(or they lament how wrong DAP is....). Generally, those photos are not showing DAP at all, but rather, are showing hind legs that are dropping DOWNWARD, toward the ground, prematurely, due to a lack of flexion of the joints or lack of energy in bringing the hind legs forward. Look instead for flexion of the hock, stifle and hip as the hind leg swings forward.

    DAP is not a matter of conformation and DAP is not about the hind feet actually visibly hitting the ground first.

    What this photo shows is not a 'side effect of DAP.' It's simply the foreleg relaxed and properly positioned.

    No, this does not mean the horse is on the forehand, and the horse at this point is not pushing off the front leg. The horse is not on the forehand. Yes, you're misunderstanding these terms and the position of the foreleg.

    The key point here is that the off foreleg is NOT in contact with the ground in a meaningful or significant way, it's merely just relaxed as it travels back in the stride, as it should be. That and DAP does NOT involve the hind feet hitting the ground before the front feet.

    DAP is instead, a moment in time, during the stride, when the hind feet drive energetically forward. It is a characteristic of top quality young horses.


     
    Last edited: Jan 7, 2018
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  3. Rhythm 'n Blues

    Rhythm 'n Blues Senior Member

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    I'm not convinced the lagging front limb is desirable or due to relaxation.

    Regardless I am in agreement that you want the limbs to move in a united way. All that said there will be moment a of time when this happens even in the best trained horses & riders. One just doesn't want it sustained.

    @StraightandTrue, Think of it this way, if the hind limb lands 1st, then what's the opposite reaction? A front limb must leave later. The only way around this is if you have half the horse moving in a different speed than the other half. Either way it's going to create a disunited odd look. By how much depends on how educated the riders sense of feel is or how educated the viewer is.

    When you're dealing with horses at the upper levels, there are different levels of collection. I.E.: 2nd level collection is different than PSG & different again from GP and yet again different from the level of collection required for Lavade. So loosing a smidge of it isn't as noticeable to everyone, but it can happen for sure.

    I'm not sure if you've seen this in some Iberian breeds, but they tend to trot a bit oddly, but people can't put their finger on why. Often it's much like what slc said, the front end moves quicker, but in an up & down motion and then you have a hind end that's driving & slower paced. That quick & higher stepping front end is often referred to as "sewing machine action". Fez had this & it was blatantly obvious when he was first started resulted in him "falling into canter" when he just couldn't keep it up or lost balance as a just backed baby. It took time to condition him to move in a more desireable fashion which would keep him sounder for longer, but it wasn't all that difficult to teach. Once I understood what "wrong" felt like & how to correct it, it was like an almost instant turn around.

    Hopefully the above has been helpful?
     
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  4. StraightandTrue

    StraightandTrue Senior Member

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    Thanks for your thoughts slc and Rhythm 'n Blues. It does make sense that the front and back end of the horse should move at the same speed, so in theory if the hind foot lands first it should also be first to leave.

    I am wondering though, if the horse maintains an uphill frame then wouldn't the angle of the horse's body (relative to the ground) mean that the front leg should spend less time on the ground than the hind leg? Not sure if I'm explaining myself very well here. If you imagine the horse is travelling like he is going up a slight hill, but the ground underneath him is flat, then wouldn't the front legs have more "air time" even if they move in unity with the hind legs because they are further away from the ground if you get what I mean?
     
  5. Rhythm 'n Blues

    Rhythm 'n Blues Senior Member

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    But that isn't how a horse moves. The horse can't do a pop-a-wheely or any variation of that.

    The transfer or weight to the hind limbs is not don't by the lifting the front end off the ground. It is done my the joints of the hind legs bending & compresing more.

    If you were to get down on all 4 and crawl/move if you compress your hind legs more your front end doesn't spend left time traveling across the ground without really disuniting the movement.
     
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  6. QRTXhorseman

    QRTXhorseman Senior Member

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    Things may not always be what they appear to be.

    Consider the height of the camera lens. If the photograph was taken with the camera lens at a height of five feet, nearer objects (the horse’s right feet) would appear lower than farther objects (the horse’s left feet). If the photograph was taken with the camera lens at a height of one foot, the difference in the appearance of the elevation of the feet would be less dramatic.
     
  7. slc

    slc Senior Member

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    No, the front legs do not spend less time on the ground than the hind leg.

    Since the hind and front legs have different joints and conformation, and slightly different jobs(look at the difference in shape of the front and hind feet....), not every stop action photo will show them in exactly the same position. They have slightly different jobs, by nature, so there are SOME few acceptable differences seen in still photos. But not many.

    The horse is not 'traveling like he is going up a slight hill' and the forelegs do not have 'more air time.'

    Though the front feet and hind feet do not follow the same exact arc through the air and this is more noticeable as the horse becomes more collected/does more collected work. Naturally, we want a horse that lifts his front feet higher than his hind feet, even before he ever gets ridden - though NOT BY MUCH. If the horse lifted his hind feet higher than his front feet(either as a green horse or a trained horse), that would not be good. You can see this fault in pics in books by old master authors like Decarpentry or Klimke as they explain that this would be a very bad fault.

    If the horse lifts the forefeet the SAME height as the hind feet, one hopes he is athletic enough to learn to shift weight to his hind legs and free up the front end, eventually.

    The key is that this difference in flight of the front vs hind feet in the air is small, and needs to not get to the point where it is exaggerated or extreme. If it DOES get like that the judges will 'score with displeasure.'

    The front feet lift higher (ideally) and so describe a different arc in the air than the hind feet because the forehand (ideally) is made lighter by the hind legs taking the weight.
    Read the FEI definition of the passage or piaffe. The front feet lift higher than the hind feet. They make a different flight arc through the air.

    Still these differences in the flight path of the front vs hind feet are small, and a good dressage rider keeps the 'front of the horse connected to the back of the horse.' If he doesn't, his rider has to correct his aids and help the horse 'stay together.'

    But we ALSO require that the hind and front feet land at the same time and both push energetically off the ground at the same time.
    Which most horses also do even if they lift their forefeet higher than their hind feet.

    Slight differences in the flight of the feet through the air do not/should not translate to significantly less time on the ground for either hind or front feet.

    IF the front feet get too 'floaty' or what's called 'oversuspended', that is usually due to rider error, not horse error. In that case, the rider corrects his aids, balances the horse and goes forward.

    If the rider doesn't notice or doesn't know how to fix this, the forehand is seen to 'climb', or lift up very slightly out of time with the lift of the hind quarters (that is in fact very hard for most people to see/detect). We see this occasionally when a horse is not naturally a good 'passager'(or he momentarily loses focus/impulsion.....) and the rider tries to give the passage more expression.

    This happens often with the 'all the generals out in front and no soldiers bringing up the rear' type of trot that some riders mistakenly produce (or some horses produce out of laziness or playfulness). This is not a 'new problem.' It's been with us forever. In THIS type of trot, the hind legs describe a SMALL, LIMITED flight arc(and both push off AND land too far behind the horse's hind quarters), and the forelegs describe a too-large (in comparison) flight arc. The hind quarters don't produce sufficient 'impulsion' and the impulsion does not create a 'circle of the aids' (flow forward through the body to the bit). This is an incorrect trot, but crops up easily in the slightest moments of inattention.

    A sound horse, if not very, very poorly conformed, makes any adjustments he needs to make in order to have his hind and front feet land and push off in unison. If he doesn't his rider should notice and try to help him.

    The forehand of the horse has a very important role in pushing the horse upward in more collected work. The forehand is very important in jumping too - the horse pushes FORWARD with the hind legs and then a split second later, pushes his forehand UP with the FRONT legs(if you don't believe this look at some ultra slow motion videos of jumpers). In jumping, the forehand sinks DOWN(more obvious in larger jumps) right before the jump so it can compress enough to provide enough lift.

    In dressage, we don't do it that way. We want the forehand not to drop down out of synch with the hindquarter. They sink and rise together. Either a jumper or dressage horse has to sink down in some way, in order to 'wind the springs' - to compress his tendons and ligaments, which store energy that is then released. But we do it a little differently in jumping vs dressage.

    Hind and front legs land and push UP off the ground nearly equally(remember some weight was shifted to the hind legs, so ground forces* at the hind feet will be higher than if the horse were not collected....), and the WHOLE horse lifts up in unison, like a hot air balloon, with the horse's back level or uphill to the front. And ideally, with his legs hanging down in a very relaxed fashion.

    And yes, his front legs will, obviously, hang down a little more than the hind feet because the front end has been slightly unburdened and lifted.

    At the LOWEST point of hind quarter lift, the joints of the hind quarters and hind legs are flexed more. The joints of the hind quarters and hind legs flex('close' or compress), and the same happens with the front end of the horse, but it's not as obvious.

    For dressage the forefeet need to land and push off in unison with the hind legs to generate maximum power, just as the horse needs to be 'straight' (ie, both hind legs pushing equally) to generate maximum extension (pushing forward) or collection (pushing upward) of the stride.

    *ground forces. What this means is that when you push on the earth, it pushes back (For ever action there is an equal and opposite reaction.). Because the earth 'pushes back' when the horse pushes on the earth, we can measure - roughly - how hard the horse pushes on the ground. That helps us understand how his muscles and tendons and ligaments compress and release - store and then release energy.
     
    Last edited: Jan 8, 2018
  8. slc

    slc Senior Member

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    Photographs and videos often distort what's happening and give false impressions. Combine that with misreads of classical dressage texts and inexperience/lack of instruction and we have a million different interpretations of what's going on (and for each interpretation, some internet guru hangs out a shingle and tries to sell us something, LOL....).

    Gait analysis is actually a huge area of study in physics kinetics and sports medicine. The gaits of many critters have been studied (including the human critter) and horses. When I took physics I happened to blindly choose a professor and wind up with a guy who had done years of gait analysis.

    There are study techniques that seek to get rid of distortion and give a clearer picture of what's going on. When researchers analyze horse gaits visually, they often use markers so they can follow the 'flight path' of specific parts of the horse. Those flights can be put in a computer and a 'kinetic model' can be created.

    The camera isn't moved so each video of each horse is videoed from the same point and has...well...the same distortions. Another technique is to use inertial sensors that can measure how quickly certain parts of the body speed up or slow down during flight, sink or rise. Force plates can estimate how hard the horse 'pushes' on the ground with his feet, too.

    Usually, the research findings confirm the 'beliefs' of 'old timers' and traditional dressage trainers. If they don't, we, well, we have a fit. It's extremely rare that any traditional dressage tenet needs any, even the slightest, adjustment.
     
    Last edited: Jan 8, 2018
  9. slc

    slc Senior Member

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    Here's a slow motion video of jumping, I'll see if I can find others.

    At about 1:50 you see a very good example of the forehand sinking DOWN in front of a larger jump.

    I've got a mistake in the post with the bolding - there's usually two hind leg thrusts - the one before the lift of the forehand, and often, another thrust with the hind legs follows the forehand lift. In some very steep jumps the forehand lift occurs and then the hind leg thrust that follows is also largely up.

     
    Last edited: Jan 8, 2018
  10. Garfield70

    Garfield70 Senior Member

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    Erm, no. It's just the natural footfall of the horse. They do it like that when at liberty, so why should that change under saddle.
     

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