Introduction

The Chest Loading Takate Kote is a modified version of the traditional Japanese takate kote, or box tie. The goal of the CTK is to improve safety and comfort when used in suspension, while as much as possible maintaining the essential functional, aesthetic, and experiential aspects of a normal TK.

Video

Errata

The wrist tie in the video is larger than I would normally tie it; I was trying to make sure it was visible in the video that there is some extra space in there. There is no need for the wrist tie in a CTK to be any looser than other common TKs for suspension; the general guideline is that there should be enough space so that the bottom can easily swap the position of their arms. If you find yourself running out of stem, you may need to make a smaller initial column tie.

Important Safety and Usage Information

This section covers things you really ought to know before using this tie in suspension.

Please also be aware that this is a very advanced tie -- as is any TK-based suspension. I would, for instance, not recommend using this in any situation where the top and bottom have less than 2 years combined experience with rope suspension. If you are relatively new to suspension, it is much safer to start out with chest-harness-based suspensions that do not put rope on the arms.

This article only skims the surface of the general safety information you should be familiar with for any TK-based suspension, as our goal here is to discuss those issues unique to the CTK; however the CTK should be used in the context of extensive suspension safety training, and an awareness of how to identify and respond to nerve issues in particular.

Background

The traditional takate kote (TK), or box tie, places two bands of rope around the upper arms, upon which a significant fraction of body weight is supported during typical usage in suspension. This is problematic from a basic theoretical perspective because the radial nerve can be compressed between the rope and the bone of the arm in this area; in practice, this problem is exhibited by a rash of radial nerve injuries presenting as "wrist drop", an inability to extend the hand at the wrist, often also affecting mobility of the fingers and thumb. Such injuries are seriously disabling in the short term (typically up to 4 months), with severe occupational and daily-life consequences, and can produce sensitivity to re-injury at the same site lasting up to 5 years and perhaps permanently.

Due to the popularity of the TK as a tie for suspension, wrist drop has become one of the most common serious injuries in the rope bondage community. While some practitioners claim that the risk of injury can be largely reduced by "correct" technique and wrap placement, a small retrospective study provides fairly strong evidence that there is no generally safe placement for TK wraps -- that is to say, any particular technique for tying a TK will be dangerous for at least some bottoms, and there's no reliable way of knowing ahead of time which people are vulnerable in which spots.

Relative Safety of the Chest Loading TK

The primary design goal of the Chest Loading Takate Kote (CTK) is to reduce the amount of pressure on the upper arms during suspension, by instead supporting the body from the ribcage. There are good theoretical grounds for believing that reducing the pressure on the arms should reduce the risk and severity of radial nerve injuries sustained in a TK-based suspension. When used correctly, it can be shown that the CTK does in fact reduce pressure on the arms, in three ways:

• By interviewing the bottom
• By examining the tension in the rope during suspension
• By examining the rope marks left on the skin immediately after suspension

However, no hard evidence exists (or likely will exist) to prove lower injury rates with CTKs than with other TK designs. Factors which could offset the theoretical safety advantages of a CTK include:

• Overconfidence inspired by using a "safer" or more comfortable tie
• Increased risk of injuries other than those caused by traditional TKs
• Errors in tying/tension reducing the chest-loading effect of the CTK

I have been teaching CTKs since 2011 and no injuries in CTK-based suspensions have yet been reported to me; however, given the extreme prevalence of traditional TKs, relatively small adoption of CTKs, and low overall reporting rates, the only conclusions that can be drawn from this are that we do not yet know what the most common CTK injuries might be.

For all these reasons, the safest policy is to treat the CTK with the same level of caution that would be called for with any other TK-based suspension. In particular, attention should be paid to placing the arm wraps away from the most vulnerable areas of the arm, to the extent such areas can be identified (the most reliable indicator being past injury), and to getting even tension on each of the 4 individual ropes of each arm wrap.

Comfort

In discussing comfort, let us start out by being clear: comfort and safety are not the same thing. A tie can be very painful, and still quite safe, or very comfortable, and still quite dangerous.

That said, there is a relationship between comfort and safety. An illustrative example is loss of circulation. There is very little inherent danger to bondage-induced loss of circulation -- when tying a large part of the body, such as an arm, it is extremely difficult to cut off the supply of blood to an extent which could cause injury. However, the symptoms of loss of circulation (tingling, numbness) are hard to distinguish from those of nerve compression, which is dangerous. So when a bottom accepts loss of circulation as the normal consequence of a particular activity, they are increasing their risk of failing to identify a concurrent nerve issue, because they have already chosen to ignore sensations which might normally provide a warning signal of the more serious problem.

Because of the wide variety of sensations which can be associated with nerve injury, almost any type of discomfort -- or any intense sensation -- likely has some potential to mask simultaneous nerve compression. So for the remainder of this section, we'll just treat comfort and discomfort monolithically, while acknowledging that in reality there are many different types of sensation at play.

One of the frequent characteristics of incidents of radial nerve injury is that the bottom reports not having felt anything unusual while suspended, and thus not noticing a problem until after the scene (or until an active check-in). A key question to ask here, however, is "what would feel unusual in that situation?"

Every suspension has a certain level of expected discomfort. I've had any number of bottoms tell me, for instance, something along the lines of "my arms might go pretty purple if you suspend me in such-and-such way, but that's normal for me, don't worry about it." Indeed, many bottoms have trained themselves to accept as normal a very high level of discomfort in TK-based suspensions; and certainly, accepting (even relishing) discomfort is a perfectly valid part of rope play. The issue is that in the context of a TK, the level of discomfort in the arms accepted as normal and the level of discomfort associated with injury are often roughly the same. Thus, even the most experienced and self-aware bottom can easily overlook the warning signs of radial nerve injury (acknowledging that there may also, in some cases, be no warning signs).

Thus, a secondary way in which the CTK can provide improved safety is by reducing discomfort, particularly discomfort of the arms. It's a fairly common occurrence for people tied for the first time in a CTK to find it revelatory in the degree to which it improves the comfort and sustainability of TK-based suspension for them -- this is particularly true among those who tend to have problems with their arms in traditional TKs. By reducing the expected level of discomfort, it is hoped that the CTK may make any nerve issues which do still occur more readily recognizable to the bottom.

Placement and Tension

Tension

With the CTK, you generally want the arm wraps to be as loose as they can be without sliding around -- this applies to both top and bottom wraps; the common wisdom of tying TK upper wraps tighter than lower wraps is not relevant here, because the arm wraps are not the major load-bearing component. The exception to this would be if you are deliberately splitting load between the arms and the chest (rather than trying to get as much as possible on the chest), in which case you may want somewhat tighter arm wraps, and may want the upper arm wraps tighter than the lower -- in fact, if you need to take some load off the chest, I would recommend starting by tightening the upper arm wraps only (as that is generally less likely to be hazardous).

While there is less tension on the arm wraps in a properly constructed CTK, there is still some; so it's important to ensure that there is even tension between the 4 individual ropes of each arm wrap. The most common place to lose correct tension is while forming the half-hitches on the left side; you can see that that happens to me while I'm demonstrating the lower half-hitch placement options in the video, and then when locking the lower left kannuki I attempt to equalize the tension by sucking a little more of the lower half of the wraps into the lock. If you observe the way the rope digs into the arm, you can see that the lower part of that wrap is still too loose relative to the upper part. What you want is nice flat wraps as exhibited by the other 3 arm wraps in the video.

Arm Wrap Placement

In terms of placement, the considerations in a CTK are the same as in a regular TK -- namely that you are trying to avoid placing the wraps on the arms where the radial nerve is most vulnerable. Unfortunately, as already discussed, due to variations in anatomy the only way to know for sure where the radial nerve is at risk on a particular individual is if they have been previously injured; and that still only tells you where the nerve is, it doesn't tell you where the nerve is not. The study I linked above seems to indicate that, from a radial nerve perspective, you really can't place the top wraps too high -- and that otherwise, very little can be said with certainty; anywhere below the deltoid is a potential danger zone.

When I am tying someone new, if they do not know their preferred placement, I generally try to get the top wraps as high as I can without causing structural problems (i.e. either bringing the kannuki up against the armpit, or not being well-anchored by the forward prominence of the shoulders), and I put the lower wraps wherever the outer arm has the most padding, i.e. generally where there is the most tricep bulk. However, it's important to be very clear on the fact that that placement -- or any other placement guidelines you might follow -- are only a guess, and unless you have x-ray vision, you don't really know exactly where the nerve may be vulnerable.

Stem Lock Placement

Another thing you need to pay attention to in the CTKv4 is where you place the upper stem locks. In the video, I have them nestled just diagonally under the shoulder blades; I find that placement works well for a majority of people with prominent shoulder blades who need fairly average wrap placement -- however, you may need to vary the positioning to get wraps higher or lower, and/or to work with the shape of an individual's back. The main constraining factors are that, when the shoulder blades are prominent, anything placed very near the edge of the shoulder blade tends to slide off it; and that in side suspension, the upper lock will pull away from the centerline, and you don't want it to get caught on the shoulder blade (which is painful). In the latter regard, too much space between the lock and the shoulder blade can actually be more of a problem than too little; if there's very little space, the lock tends to pop over right away, whereas if it can move halfway into position before encountering the shoulder blade it is more likely to catch.

In tying people whose shoulder blades don't protrude significantly, you have much greater freedom with placing the locks, and can allow lock placement to be dictated almost entirely by what best facilitates the desired arm wrap placement, subject only to not making the upper kannuki so high that they dig into the armpit.

Contraindications

Any person who has been advised by their doctor to avoid pressure on the ribcage should most definitely not be suspended in a CTK. The CTK may also be unsuitable for people who experience discomfort due to rope bulk of kannuki in the armpit area, and people who require very high upper wrap placement which would bring the kannuki into contact with the upper surface of the armpit.

This is not an exhaustive list; there are many other reasons it might be unsafe for a particular individual to be suspended in a CTK, any TK, or at all. Every tie must be intelligently evaluated for appropriateness for any given bottom and situation.

Modifications and Alternatives

Alternate Support Line Attachments

Face Up

The video demonstrates attaching the support ropes for a face-up suspension to only the horizontal wraps headed around the arms. That is the most-tested and safest approach; however, it also appears to work fine to include all the ropes crossing the center-line of the chest (that is, also incorporate the shoulder ropes which cross the centerline). In my tests, the bottom did not report any significant difference in comfort, and I thought it looked better. It probably does slightly affect the loading of various components of the tie, but I don't see any theoretical basis for any of those effects being problematic. This is an area where informed and careful experimentation may be fruitful.

Side

There is a method shown in one of the original CTKv1 videos of attaching support lines for side suspension inside the kannuki. I don't think this would have any particular benefit with later CTK versions, and haven't tested it with the v3 or v4 CTK. However, it should still be possible; structurally, it loads the tie in the same place as face-up suspension. Note that a couple of very vocal critics have expressed concerns that that technique could be dangerous to the nerve cluster on the inner arm just below the armpit; while I have never heard any report of such an injury, due to this or any other tie, I would certainly advise against using the alternate side-suspension attachment if it causes any sort of discomfort to the top-side arm.

Face Down

There are many other ways you could attach to the back of the CTKv4 besides the two shown in the video. Some of them would produce different loading, which could be useful, as face down tends to be the most difficult position for bottoms in this tie due to pressure on the front of the ribcage. Be aware that if you directly load the over-the-arm wraps from the back (i.e. without also going under the kannuki below them) you will significantly increase pressure on the arms, negating any safety benefit from the chest-loading design and possibly creating hazards in excess of those presented by a traditional TK. Proceed with caution.

Partial CTK / No Upper Kannuki

I have previously published one design for a partial CTK where only the bottom wraps use the chest-loading method. Variations like that may be useful for bottoms who don't tolerate upper kannuki well, or for performance settings where speed is critical and a higher level of risk is acceptable. I would recommend using the v4 approach for forming the lower wraps, and considering a triple top wrap, as a starting point for any experimentation in that direction.

Non-doubled Shoulder Lines

If you don't need the doubling of the shoulder lines for your particular bottom or situation, there are plenty of other things you can do at that stage instead that save rope and/or provide other functionality. One option would be to do munters across the front, as in the CTKv3. Another variation I really like when tying on someone with large breasts is to pull up the lower wraps in the front, as follows:

This is me tying on Tifereth, filmed by Cannon at NARIX. You'll notice that in order to do this, I left coming back to the front until after doing the second arm-wrap module; it's fine to do that if you want to incorporate the lower wraps into whatever you do in the front.

Theory of Operation

This section contains detailed information on all the various design decisions embodied in the CTKv4; while you don't necessarily need to understand all of this in order to use the tie, it may be helpful in being able to effectively adapt the tie to different bottoms and situations.

Arm Wrap Half Hitches

The half hitches on either side of the front of each arm wrap exist to create a stop for the kannuki; preventing the kannuki from sliding outward past a certain point on the wraps is the fundamental mechanism which makes all CTKs load the chest. You can visualize how this happens as follows:

Think of where the support line attaches in a face-up suspension. As the tie is loaded, the rope of the arm wraps is pulled from both sides towards the center of the chest, creating slack which pulls away from the chest. Normally, as the rope is pulled toward the center, this tightens the wraps around the arms until the outward force generated by the arms balances the inward force generated by the suspension. In the CTK, as this tightening begins to happen, the half hitches are being moved toward the center of the chest -- however, the kannuki, which are inside the half hitches, oppose this motion; in order to continue to slide toward the center of the chest, the knots must pull the kannuki forward along the ribcage. This is what transfers the force onto the ribs, and why the kannuki must start out tighter than the arm wraps to be effective; if there is more slack available in the kannuki than in the arm wraps, the kannuki won't start pulling back against the half-hitch until the wrap has already tightened on the arm.

Direction of Half Hitches

When doing the half hitches, I always do the first hitch over-under, then the second under-over. This isn't just for symmetry; there's a functional reason for them to be in those respective orientations. If you pay attention to how the rope exits the half hitch, in one direction it's pushed up away from the body, and in the other down toward the body. The side that is pushed up is at greater risk for popping up on top of the previous wrap; since that would be particularly bad on the arm, we orient the half-hitch with that side toward the chest, where crossed wraps is not only less dangerous, but also where the kannuki will help hold everything in its proper place.

Comparison to Previous Methods

In CTKv3, half hitches are also employed to create the stops, but the half hitches are tied after the kannuki. This avoided the tendency to cause a pinch while tightening the kannuki, but often made it harder to get sufficient tension on the kannuki. CTKv4 returns to doing the kannuki last, allowing them to be easily tensioned as much as you might want; pinching can be avoided as shown in the video. In v4, the kannuki also capture 3 of the 4 ropes going across the front of the chest, instead of only 2, which spreads the load a bit more evenly in that part of the tie for face-down positions.

CTKv2 used the bulk of overhand knots instead of leaving out part of the wraps to capture the kannuki; this was both harder to tie and less reliable than half hitches; it has no clear advantages. CTKv1 used a method which was a complete pain and also has no clear advantages over half-hitches.

Stem Formation

Both the CTKv3 and CTKv4 form a stem by going over the shoulders at the beginning, rather than going straight into the upper wraps. The main impetus for this has to do with achieving correct tension on the upper arm wraps. In a normal TK, the desired tension on the upper arm wraps is generally similar in scale to the tension necessary for a firm stem. This makes it reasonably achievable to form both at once, and to isolate tension between them with the friction of the upper arm wrap lock. However, in the CTK, you want arm wraps that are significantly looser than you want the stem to be; this turned out to often be difficult to achieve in practice with the CTKv2; it was common to wind up either with the stem too loose, or with one or both arm wraps too tight.

The over-the-shoulders stem formation in the CTKv3/4 allows a high-tension stem to easily be created at the beginning of the tie, in isolation from wrap tension -- and then provides the opportunity to relieve/adjust the tension on the shoulders later in the tie, once the structure of the stem is sufficiently reinforced.

Split Stem

The most dramatic change in the CTKv4 is the elimination of a central stem in favor of two side-stems. What got me thinking about this was the realization that in the most complete 3TKs, you essentially wind up forming two additional stems at the end, between the munters on either side of the wraps in the back -- and that the better-tensioned and better-frictioned those are, the more they take over the structural role of the central stem. So if the side stems are already starting to take over for the central stem, why not just skip the central stem and focus on strong side-stems from the outset? Turns out, as far as I can tell -- no reason.

There are some trade-offs. While the split stem approach seems to save a bit of rope, and create far more structural side-stems, the positioning of the split stems generally winds up slightly closer to the centerline than where you would put the munters in a 3TK, particularly on the bottom. This may reduce their ability to stabilize wrap position on the arms -- although, the reduced positional effectiveness may be offset by the increased rigidity of the side-stem. It's a difficult thing to quantify, but seems to maybe be a wash.

In the context of the CTK, a big advantage of the split stem is that it avoids running out of space on the stem due to the extra locks required, and makes it easier to get closer spacing between upper and lower wraps (if you're into that), as well as to properly align all the kannuki with their respective arm wraps (an issue discussed in more detail in subsequent sections).

Another benefit of the split stem is that it moves the bulk of the stem off the spine, making this a very comfortable TK to lie on your back in.

I haven't tested it, but I can't see any reason the split stem approach couldn't be adapted to non-chest-loading TKs as well.

Doubled Shoulder Lines

Particularly in positions where the shoulders are lower than the hips, pressure on the collarbones and trapezius can be really difficult for some people. I'd been using doubled shoulder ropes in shinju chest harnesses for suspension for years, but for some reason hadn't thought to try to incorporate them into a TK until I saw Peter Slemrian's way of doing it at Shibaricon.

When I started playing with this, it quickly became evident that the main difficulty was achieving even loading between two shoulder ropes that were not anchored to the rest of the tie in the same way as one another. The weaving between the two shoulder lines in the front of the CTKv4 is specifically designed to combat this phenomenon; in this arrangement, if one rope becomes looser than the other, the point where they weave through each other will simply be pulled slightly to one side or the other until they are re-equalized. Depending on how toothy your rope is, small inequalities may not be enough to overcome static friction; but you can always help it along.

This approach could likely be of great use in non-chest-loading TKs, as well; there isn't anything specifically CTK-related about it, it's just an extra feature I threw in because I think it works well.

Doing the Third Rope Second

Another change in version 4 is that I do the "third rope" stuff in the front -- rearranging and doubling the shoulder lines -- before completing the lower arm wraps and kannuki. There are two reasons for this.

The first reason is functional: the point where bottoms most frequently have difficulty in CTKs is near the lower-wrap half hitches, where the ribs are very exposed and bend sharply in many people. Because this area is already being loaded to an extent which can be uncomfortable, we don't want to unnecessarily place more pressure there -- and when you return to the front after completing the second arm-wrap module, that's exactly the area the rope passes over. By returning to the front earlier, you instead pass along the ribcage in an otherwise-unused area between the two sets of wraps, both avoiding extra load where it's undesired, and increasing the overall area of the ribcage over which load is spread.

The second reason I like this approach has to do with the flow of the tie. Most experienced bottoms have been tied in a lot of TKs, with a very familiar rhythm to them -- one set of wraps, another set of wraps, a bunch of finishing stuff. I find it provides a fun, surprising element to upend this order of things with the CTKv4, by breaking up the repetition of the arm wrap modules with the "third rope" front stuff in between. Combined with the fact that the in-the-back third rope stuff is taken care of in the course of tying, this also provides a very surprising finish -- you do the last kannuki, and boom, you are done! This avoids ending the tie with a long bit of fiddly work that can be a bit of a downer compared to the more dynamic action of forming the wraps.

Stem Structure

Locks and Friction in a Traditional TK

In analyzing the stem structure of a CTK, it is helpful to first have in mind a clear idea of the function of stem locks in a normal TK, so as not to be mislead by deceptive similarities.

Taking as an example the popular Osada Steve style TK, there are two main locks on the central stem; an X lock around the upper wraps, and a half-moons lock around the lower wraps. Such locks (sometimes called "frictions") have as their major purpose the isolation of tension between different sections of the tie. There are two ways in which a lock can achieve this: first, by creating friction around something that passes through the lock; and second, by virtue of the structure of the lock itself preventing tension from moving between the two sides of the rope forming the lock. We'll call these "frictive" and "structural", for the sake of discussion.

Thus, in the OS 3TK, the X lock at the top provides the following isolation (assuming you tie starting to the left):

• Between the stem and the first upper wrap (frictive)
• Between the first upper wrap on the right side, and the second upper wrap on the left side (frictive)
• Between the second upper wrap on the right side, and the first kannuki (structural)

The half-moons lock, likewise, provides the following isolation of tensions:

• Between the first lower wrap on the right side, and the second lower wrap on the left side (frictive)
• Between the second lower wrap on the right side, and the first lower kannuki (structural)

You'll notice that I don't list isolating the first lower wrap from the final upper kannuki amongst the functions of the lower lock; this is because that function is primarily fulfilled by taking a wrap around the stem between completing the kannuki and moving on to the lower wraps, which is in itself a lock of sorts, performing only that one function (in the "structural" way). However, the half-moons lock does play a supporting role there, in that it helps ensure rigidity of the stem, which is key to any lock (but especially a simple wrap-around one) being able to function.

This is all admittedly a bit convoluted to write out as such, but there's a key insight to be gained here -- if you look at places where the isolation being created by the lock is between things of roughly like tension (various arm wraps, and the stem) it is always frictive. Conversely, if you look at combinations of unlike tension (arm wrap vs. kannuki) they are always structurally isolated by the locks. This is because frictive locking is only powerful enough to prevent slippage between lines with a small difference in tension -- a key challenge in designing the stem for a CTK.

CTK Side Suspension and the Stem

Imagine for a moment a CTK structured exactly as the OS TK discussed above, only with the addition of the load-transferring half-hitches in the front. If you perform a side suspension by attaching support lines to the right arm wraps, what will happen? Let's analyze it line by line:

• The topmost wrap will start to pull on the top X lock, which is anchored to the stem, the stem in turn being anchored by the tight left-hand kannuki. All the slack in the kannuki will quickly be exhausted, at which point there will be body-scale forces outward on the topmost right wrap, but very little tension where the same rope exits the lock on the left side to become the second left-hand wrap. This rope pulls through the lock, tightening the second upper wrap on the left arm until the tension is roughly equalized.
• The second top wrap on the right side is structurally locked to the stem by the X lock; its force is taken by the left-hand kannuki.

...and then the same pattern repeats for the lower two wraps.

This is a somewhat ugly picture. You wind up with a majority of the force all being supported by one side of the kannuki (remember that the lower side of the kannuki doesn't anchor to the stem at all on the left), and whatever remains on just half of the opposing arm wrap, which is now unevenly tightened. It only gets worse from there -- the kannuki which is taking all the force is only anchored by the friction of its 180 degree turn around the wrap in the front; if the force overcomes that friction, now all the slack from both sides of the kannuki is free to migrate into the one supporting line. That slack then allows the entire stem to slide to the right, until all the weight is being borne by the left arm wraps -- the now-unevenly-tensioned left arm wraps.

Altogether, this is the main problem to overcome in building a solid CTK.

We start by making all components of the tie lock structurally to the stem. This is why there are so many more locks in a CTK; an individual lock can only provide strong, structural isolation between 2 components (whereas it can provide weak, frictive isolation to several at once). However, a more subtle difficulty then emerges: in normal TK construction, where you always work down the stem, both sides of the kannuki meet the stem below both sides of the arm wrap they are connected with, i.e. you get a vertical ordering on the stem of:

• Left arm
• Right arm
• Left arm
• Right arm
• Left kannuki
• Left kannuki
• Right kannuki
• Right kannuki

So in the side suspension we examined earlier, that results in a balance of forces like this:

      <= A |
           | A ======>
      <= A |
           | A ======>
  <===== K |
  <===== K |
           | K
           | K

And if we'd chosen to suspend from the other side, the situation is even worse:

 <====== A |
           | A =>
 <====== A | 
           | A =>
         K |
         K |
           | K =====>
           | K =====>

This offset loading causes the stem to twist -- even if everything is locked together in one big lock, the whole lock twists -- and that twist allows tension to leak out of the kannuki and into the floor-side arm wraps.

In the CTKv3, this problem was addressed through some crazy ordering and wrapping that was pretty difficult to remember, and used up a lot of stem. The CTKv4's split stem allows a much more elegant solution, where only one up-the-stem move is required -- the 3/4 moon lock before each kannuki. With that, and the split stem, our force diagram now looks like:

  <===== K | === | K
      <= A | === | A ======>
      <= A | === | A ======>
  <===== K | === | K

Or, with the left arm attached to the ring:

         K | === | K =====> 
 <====== A | === | A =>
 <====== A | === | A =>
         K | === | K =====>

You could in theory achieve the same balance with an ordering of AKKA instead of KAAK, but there's a third subtle issue here. When you lock together the kannuki and arm wraps (providing important structural support to the stem), whichever ropes are topmost and bottommost get sucked toward the middle of the lock, slightly increasing the tension on them. Since we want the kannuki tighter than the arm wraps for the tie to function properly, it's advantageous to have this tightening occur on the kannuki rather than on the arm wraps, thus giving preference to the KAAK ordering.

If you managed to follow me through all that, please now pour yourself a drink. Your brain will stop hurting in a couple of days.

Troubleshooting

Here are some common problems, and likely solutions.

Still Getting Load on the Arms

It goes deeply against the instincts of anyone used to traditional TKs, but you really have to get the kannuki pretty tight -- they should be tighter than the arm wraps. You may also need to tie the arm wraps looser than you are used to; they should be at the far loose end of the range of tension commonly employed with TKs.

Also, the tension will never be 100% on the chest; the most you're likely to get would be around 80% chest, 20% arms, with 70/30 more typical (and generally preferred by bottoms). However, the difference from a normal TK should feel dramatic. If it feels more or less like a regular TK in suspension, your tension is almost certainly way off (or something else is majorly wrong).

Bad Shoulder Tension

If your shoulder ropes wind up too tight or too loose, try varying the height at which you cross the lower back when forming the initial X. In general, going higher on the back will produce tighter shoulder ropes. How tight they should be is pretty situational.

Tying Around Large Breasts

With large breasts, the main thing that changes is that things below the breasts get pushed down from where they'd normally be -- so in terms of setting up the initial X, you may find that if you go straight across the back at under-the-breasts level, it comes out too low.

It's a little tricky to explain what "too low" means in this context; the issue is that when you move the ropes up over the breasts later, you want to be able to get all the available slack to the front right away -- not have any hidden slack that can creep in later by the line across the back sliding slowly up at the center. So if you have tension issues with the shoulder lines, try going across the back higher, at the natural height relative to the final position on the front, rather than the initial under-breast position.

Also, be sure to try the variation for Tifereth. That supports the lower wraps in the center, which can keep them from being pushed into an uncomfortably low position by the breasts.

History and Credits

The road to the CTKv4 has been a long one; I've been experimenting with chest-loading alternatives to the TK since at least 2010. There's no way I can list everyone who's helped me in some way on that journey, but a few people deserve particular recognition: Ropeboi and Nell for providing endless invaluable testing and feedback over the years; Amy Morgan for some essential help at the beginning; and Ay, for early testing and encouragement as well as being instrumental in setting me looking in the first place.

You can find the original post on CTKv1/2 here, and on version 3 here.

Cheat Sheet

You can find a 2-page photo cheat sheet here; some people find that a useful visual aid while practicing the tie.

Written Description of Tie Sequence

Patterns to Remember

• Always left side first
• Lock to left stem before an arm-wrap
• Always under the stem
• 3/4 moon lock on near stem before a kannuki
• L lock on near stem after a kannuki
• Extra wrap around stem after L locks on right stem only

Full Sequence

• Stem formation:
  • Wrists
  • Over left shoulder
  • Under right breast
  • Straight across back
  • Under left breast
  • Over right shoulder
  • Straight through wrist cuff right-to-left (behind knot)
    • Check upward tension on wrists now
• Top wraps:
  • Half-hitch around left stem at upper-wrap height (this is the before-arm-wrap left stem "wrap" for the first arm wrap)
  • Wrap to the left around both arms and chest
  • Under both stems, wrap around left stem
  • Second top wrap, with half-hitches
    
    • First hitch over-under, second hitch under-over (mirror image)
    • Position just on chest side of arm/chest gaps
    • Check equal tension on left arm wraps after first hitch
  • Under both stems, 3/4 moon on left stem
    • Check equal tension on right arm wraps after first half of 3/4 moon
  • Left kannuki
    • Comes out inside the hitch, skipping only the top-most single rope
    • Tighten carefully to avoid pinching; should be tight and neat!
  • Under left stem, L lock on outside of left stem (include arm wraps and kannuki)
  • Under right stem, 3/4 moon on right stem
  • Right kannuki
  • Under right stem, L lock on outside of right stem (include arm wraps and kannuki)
  • Extra full wrap around right stem
• Lake Ashi (i.e. the part near a Mt. Fuji):
  • Under left stem, through left elbow-hole to front
  • Pop both shoulder ropes over the breasts, using slack to spread away from the neck
    • Crossing point must be shifted to below the top wraps
    • Be sure to get all the slack to the front and spread them wide
  • Weave the new rope under the left-shoulder rope, then over the top wraps
  • Over the left shoulder
  • Loop over-under the entire group of horizontal lines between stems, coming up on the left
  • Over the right shoulder, back to front
  • Weave over the top wraps, under the previous right-shoulder rope
  • Through the right elbow-hole to the back
• Bottom wraps:
  • Under both stems, wrap around left stem
  • Wrap to the left, around both arms and chest
  • Under both stems, wrap around left stem
  • Second lower wrap, with half-hitches
    • Position from just against the chest, to midpoint between chest and arm, depending on ribcage shape; usually closer to chest is better
  • Under both stems, 3/4 moon on left stem (only include the two arms wraps)
  • Left kannuki
  • Under left stem, L lock on outside of left stem (include arm wraps and kannuki)
  • Under right stem, 3/4 moon on right stem (only include current rope and the two arms wraps)
  • Right kannuki
  • Under right stem, L lock on outside of right stem (include arm wraps and kannuki)
  • Extra full wrap around right stem (if room, to help keep the tension while tying off)
  • Lock off with a half-hitch or two somewhere; done! (around the lower center-horizontal bundle is usually convenient)

Related Work

There is an unpublished technique by Trialsinner which I describe here that can work well for adding arm support to a Shinju suspension harness. It's somewhat a matter of taste; some bottoms really like it and some it seems to disagree with.

Precipice has done some work on an alternate approach to a chest-loading box tie. While I find the published version of the tie to have problems which render it essentially unusable, the basic idea behind it is interesting.

Jahc has posted photos, but not instructions, for another tie designed to be chest loading.