General anaesthesia and flexibility: how much does the central nervous system affect flexibility?

[Jim Pickles]

I’d like to discuss a statement I put in the “Question for Kit” thread. This is the statement: "The evidence for this, as often quoted, is that under surgical anaesthesia, it is possible to put someone in a perfect split. As the anaesthesia wears off, the usual pattern of flexibility returns."

I have started a new thread on this topic, because it seems to be diverging from the original query.

I have heard the opening statement many times, and on querying it seems the information has come from people who should really know, such as orthopaedic surgeons.

Please note that issue here is not whether the brain does or does not have some effect on flexibility; it is clear that it does, because we all know that voluntary relaxation can increase a stretch. Neither is the issue whether our normal pattern of muscular tightness is under the control of the brain: of course it is. If we were fully relaxed, we would not be able to stand up. Anaesthetics clearly abolish this pattern of muscle activation, and if we were anaesthetised while standing we would expect to fall over. In addition, some people carry more muscle tension than the minimum needed to stand up, and it quite reasonable to think that this also is driven by the brain, that it should disappear when we are anaesthetised, and reappear when we come out of the anaesthetic.

Rather, is a question of how much flexibility, or lack of it, is driven by the brain – because a perfect split needs a very great deal of flexibility, far beyond the range of most people.

If the opening statement was true, it would mean that the properties of muscle (or other associated tissue, such as connective tissue) would have NOTHING to do with flexibility (at least up to the range needed to give a full split). It would ALL be due to (1) neural reflexes, with (2) the ultimate limit set by joint properties. Because this conclusion is rather surprising (as well as going against a great deal of current exercise science), I thought I’d look into it further, to see where the evidence comes from.

If indeed it is something reliable known to the medical world, then the information should be found in authoritative sources such as medical textbooks. So I did Google searches using different variants of the terms. However, although I found many references to the issue, they were all in exercise-related webpages, rather than in authoritative basic sources. Usually, it was just a throwaway statement, and never with a justification saying where the evidence had come from.

However, there was one helpful comment in an article by Craig (yes, the same Craig who posts here; thank you Craig), in Aware Relaxed Connected¹. It quoted an experiment by Robert Schleip², who tested the effect of anaesthesia on flexibility, in patients who were about to undergo surgery on the knee.

(1) Before and during anaesthesia, Schleip² raised the arms of the supine patients, to see how high they would go. In 1 out of the 3 patients tested, before anaesthesia the arms could be passively taken right overhead and lie against the table – so no increase in range in this patient could be expected. In the other 2 patients, the arms did not lie flat against the table before anaesthesia, but did during anaesthesia. So anaesthesia increased the mobility of the shoulder joint in these two (though he did not quantify by how much).

(2) He also dorsiflexed the feet of the patients. None of the 3 patients showed any noticeable increase in range; i.e. there was no sign that the calf muscle had become more extensible.

So it seems that one joint (a complex one, where many factors will determine its mobility) could be affected by anaesthesia, but simple muscle length could not.

I then searched the medical literature via Pubmed. I found only one paper that had addressed the issue “Neurophysiologic influences on hamstring flexibility: a pilot study”³.

In this study, the hamstring flexibility of a healthy leg was assessed before during and after anaesthesia, in patients about to undergo surgery on the other knee. Averaged over all 11 subjects who had general surgical anaesthesia, there was NO change in the flexibility of the hamstring as a result of anaesthesia. Over the 3 patients who had spinal anaesthesia, there was a small increase in flexibility during anaesthesia (average change in popliteal angle 8.1 degrees – enough to allow the foot to move by another 5cm or so). Mean popliteal angles with hip held at 90 degrees were around 130 degrees – i.e. the subjects were not particularly flexible, either before or during anaesthesia – certainly nowhere near to doing a “full split”.

The clear conclusion from this paper is that loss of central control has NO effect on hamstring flexibility, contra the opening statement. Spinal anaesthesia (which will also affect motor neurones and local spinal reflexes) has a small effect. In neither case does anaesthesia allow anything remotely near to a full split.

My conclusion from this reading is that the opening statement is inaccurate. In people lying conscious on an operating table, the nervous system only has very minor effects on leg flexibility. When neural control is removed, there is only a very minor increase in leg flexibility.

1 Found at: http://awarerelaxedc...-motion-basics/

2. Found at: http://www.somatics....ging-the-brain. Source: Talking To Fascia – Changing The Brain - Explorations of the Neuro-Myofascial Net by Robert Schleip. Rolf Lines March/April 1991:

3 Abstract found at: http://www.ncbi.nlm....pubmed/11753061 (the full text needs a subscription). Reference: Krabak BJ, Laskowski ER, Smith J, Stuart MJ, Wong GY. (2001). Neurophysiologic influences on hamstring flexibility: a pilot study. Clin J Sport Med. 11(4):241-246. (As far as I can tell, this study has not been followed up or repeated.)

[Craig]

Hi Jim,

Great topic and one I've wondered about myself. I have also not found anything super conclusive, however there is some contradicting information in everything I have researched, especially between Robert Schleip's older research and some of his newer stuff.

A couple of bits:

"Furthermore, Dr. Schleip has influenced the Rolfing community by demonstrating the importance and interconnectedness of the nervous system with the myofascial system of the body (9). Dr. Schleip made an interesting discovery when he participated in 3 arthroscopic knee operations where patients were given general anesthesia. Dr. Schleip performed passive range of motion tests before and during the anesthesia, and to Dr. Schlep's surprise, the range of motion tests showed an increase when the patients were anesthetized. This work clearly points to the importance and interconnectedness of both the myofascial system and the nervous system and how both influence structure and flexibility in a client’s body, and therefore must be considered during the Rolfing process."

from http://www.medicalwellnessassociation.com/articles/rolfing.htm, the reference (9) is pointing to this book: 9) R. Schleip, Explorations of the Neuromyofascial Net, Rolf Lines, April/May, 1991

In regards to your point about ankle flexibility, it seems that the patients already all had good ROM's, which could account for the lack of noticeable increase: "(I was not surprised by the unchanged mobility of the ankle joint, since none of the 3 patients seemed to have any limitations there that would concern me as a Rolfer)."

This information is also backed up in the same article by several statements:

Clinical in vitro studies have shown that short term mechanical deformation of animal tissue results in elastic form changes only, whereas a long-term deformation of at least 10 minutes per spot would be necessary to cause any permanent `plastic' (viscous) changes. I am now fairly well convinced that what we experience as "fascial plasticity" during our very short term Rolfing strokes is, in fact due to the plasticity of the neuromuscular system. Skilful stimulation of various nerve receptors (specially Golgi organs) in fascial sheets can evoke changes in muscular holding patterns and furthermore in the brain's body image.

I have to disagree with your current conclusion, and agree more with your conclusion in the other thread: That the neural maps play an important role up until a certain point, but also that a degree of physical restructuring is necessary for a large amount of change.

This also seems to be in line with my own observations of my students. Just yesterday I observed a student go into a standing side split (without the hands on the ground, so it was just the muscles being stretched holding her up). She was wearing socks on a wooden floor so it was extremely slippery. She started with her groin about 2 feet from the floor and assured me this was as deep as she could comfortably go. She held the split for 30s or so, and during this time was descending slowly. I then had her immediately perform 5 reps of squeezing her legs together all the way to standing from the deepest position of her split (she was allowed to use her hands on a support to compensate for the current lack of strength. After the 5r, she went down into her best unsupported side split again. This time, she was about 6 inches from the ground. She had dropped a full foot and a half in the space of about 90s. I honestly believe that if she had the capacity for deep relaxation and the ability to overcome the panic sensation, that she could have easily gone all the way to the ground, but her system stopped her in this case. I really can't see how any physical restructuring can happen in such a short time period, so this change was completely neural as best as I could tell. I have regularly seen similar results at Kit's workshops (as I am sure you have).

It may also be (and in my opinion almost certainly *is*) a case of different strokes for different folks, and also that relative strength of the muscles in the lengthened position has an enormous impact. Another anecdotal example: I have been stretching tailor's pose for some time now. When I first attended one of kit's classes, my knees were up around my shoulders, but i decided I was strong enough to support Liv's entire weight (and several times after that, Kit's entire weight). Kit especially being heavier, was able to push my knees all the way until they were flat on the ground, a range of motion I had previously never ever experienced in my memory (probably only when I was a toddler). It was about 15s for this change to happen...the tissue was more than physically long enough to perform the move, the nervous system was simply unwilling, and I was only able to access it when the power of the muscles was overcome by extreme weight. Oddly enough, somewhere between 5 and 15 mins after going all the way to the ground, I tried again without weight and my flexibility had returned to its previous state.

Of course I don't have any letters after my name so these observations probably don't hold as much weight as if Dr. Shleip had written about the exact same observations, but that's a whole 'nother bag of worms

[Kit_L]

I can only quote a surgeon friend of mine who is one of the world's experts in keyhole surgery, and from a conversation only a few months ago. He said that, recently, a man literally shaped like a prawn (very strong kyphosis) was laid down on the operating table face up. The back of his head was a foot from the table; he could not lay down on the table voluntarily. Over the course of the administration of anaesthetic (and muscle relaxant; liquid Valium in Australia) and this took about five minutes, his body relaxed down onto the table completely: he was now lying flat.

When the same chemicals wore off, his body went back to its habitual shape. These are the effects I talk about on workshops: that the mind and its image of its capacities does constrain what is possible, while conscious, up to physical limits of the joints. Having said this, and knowing about fascial changes that occur during one's life, I am reasonably sure that fascial changes will not be influenced to any great extent by anaesthesia. But we simply do not know.

Robert Schleip told me personally about a time when he and (from memory) two other colleges assessed a fourth colleague (ROM assessment; spinal alignment, etc.) and then the fourth member was anaesthetised and Rolfed extensive while under. When conscious, and reassessed, not any aspect had changed. RS's conclusion (identical to the position I take more generally) is that if the conscious mind is not involved the change, it did not happen.

One more consideration: a friend has DISH; his vertebrae are fusing. No amount of anaesthetic will change this. What would be interesting to try (not that this will happen any time soon) would be to anaesthetise a child (say 10 years old) in whom the more restrictive fascial changes are yet to occur, and see what ROM is available then. IMHO, the research simply does not allow one to come to a conclusion either way.

Re. Craig's comments: his are my experiences, too. And the return to normal ROM after a breakthrough session is also my experience. But, and Craig may care to comment on this, once the DOMS has settled (and this can take long than one might think, depending on the depth of the breakthrough), the muscles feel completely different to work; they are more yielding, and feel less resistant to elongation. My conclusion is simply that the available range has been remapped. As most here know, my tailer pose is relaxed legs on the ground; when I started, mine was worse than Craig's. This change took me five years (when I was in Japan, mostly, so a long time ago), because I had not discovered the most important of the contractions (pushing the soles of the feet together).

Big picture now: the body generally gets drier as one ages. According to the good doctor, though, one's hydration regime has little, or no, effect on the wetness of one's fascia—but one's movement regime has a profound effect. As a tissue, fascia has a half-life in the body of about six months, according to Schleip. By incorporating more and more varied movement (and springiness activities, too) for about two years or so, one can renew the capacities of one's fascial body. In my view, this is about the minimum time period that one needs for more advanced flexibility moves as well, assuming a reasonable starting point. Jim may care to mention how long it took him to get his excellent splits. All up for discussion.

[Jim Pickles]

Kit and Craig – many thanks for your replies – you were the two who I was hoping most would respond.

Kit – I don’t doubt that story (of the man on the operating table) at all – it sounds very reasonable, and has also been described a number of times in the literature. Similarly, as I say in my posting “some people carry more muscle tension than the minimum needed …, and it quite reasonable to think that this also is driven by the brain, that it should disappear when we are anaesthetised, and reappear when we come out of the anaesthetic.”

However, this is not the issue I was addressing. I was addressing the statement: "The evidence for this, as often quoted, is that under surgical anaesthesia, it is possible to put someone in a perfect split. As the anaesthesia wears off, the usual pattern of flexibility returns."

The critical part is that under anaesthesia, we should be able to do a perfect split (1). The critical words are “perfect split”. This is not born out by the evidence I found, nor by your example, which does not address it.

The statement also carries the very important implication that the ONLY thing that stops us having perfect flexibility (up to the level of being able to do a split) is our neural control, until we get to the physical limitations of the joints themselves.

If the statement (1) is not born out by the evidence, then this conclusion does not follow (even if it is true for other reasons; but then the evidence for those would then have to be produced).

But it is interesting that neither Kit nor Craig directly addressed the point I was making (but, rather , slightly different points) – maybe this is not really how you see the issue?

Its probably best if I don’t go into more detail because there are lots of things I could discuss in the posts, but the nutshell of what I am saying is above, so adding more detail would be a distraction. If you feel I am avoiding anything that I should discuss, please let me know. But I do appreciate both Craig and Kit’s responses; thank you.

So moving on:

There is a point that you have both made which agrees with my own experience: Craig’s comment about the breakthrough with Kit standing on his knees in tailor pose, but not being able to repeat it, plus Kit’s comment “and the return to normal ROM after a breakthrough session is also my experience”. Same here, especially with inner thighs (maybe because fascia are so heavily involved here?). While I try normally to hold stretches, especially of the inner thighs, for at least 30 seconds, I often can’t resist doing a much stronger (and hence shorter) one at the end (especially when I'm in the straddle split machine). And because I feel sore after that (or feel I might injure myself if I repeat it), I don’t try again until I have fully recovered. In other words, you could say that afterwards my ROM goes back to what it was before (I call it being sore or feeling I might be, and not wanting to risk it). However, I do feel that sometimes these extra strong, very short, stretches lead to me getting an enhanced ROM at some later time when I have recovered. This is why I persist in doing them, though I know they carry the danger of a pulled muscle a few days later when I am using the muscles for something else. You suggest it is remapping; I suggest that it might be a mechanical change, probably temporarily masked by the soreness.

Other points:

1. I do find the issue of whether we have to be conscious and aware during manipulations for them to have an effect a very interesting one, though to test that properly would need a detailed scientific study (the changes would have to be accurately measured, because one would be comparing the size of manipulation effects – difficult to measure at the best of times – in different subjects and/or in quite different occasions). But doable under the right circumstances.

2. This brings to mind some recent thoughts I had been having about Ramachandran’s ideas (I think you know about him Kit – I think you have mentioned him in the past). We heard a lot about him where I used to work because my old head of dept had been a colleague of his. Here, I am referring to the way he is able to reduce the pain from an “immobile” removed (phantom) limb – the limb being immobile because it has been removed, and so the patient cannot move it to get rid of the cramping phantom pain coming from its phantom muscles. He arranged a mirror so the patients real limb appeared to be in the position the phantom limb would have been. Then the patient moved his real limb in the way he wanted to move his phantom limb, and saw (in the mirror) what looked like his phantom limb moving, and lo and behold, the pain disappeared.

I wonder, is it possible to arrange it so that someone sees or feels their body moving into a position that is just outside their normal ROM, and see if the person’s ROM magically improves? That would be another was of testing the “all in the brain” idea, as well as potentially giving benefits in terms of increased ROM. I think its worth a try.

As for time to achieve splits: Started trying at about age of 48 (when I was very high indeed off the ground). 20 years later I am still improving, in terms of squareness of hips, how hard I press the pelvis into the floor, frequency (now whenever I want, rather than just breakthrough occasions), and lessening of warmup needed. From starting, to getting down (though crooked) on my better side, probably 4-5 years.

Cheers,

Jim.

Edited later to remove one of the later paragraphs which was a distraction from the main message.

Edited October 21, 2014 by Jim Pickles

[Craig]

Hi Jim,

I haven't seen any evidence myself of the side splits under anaesthetic thing, although I am guilty of repeating the wives tale that I've been told by many people. As best I know there is no conclusive evidence either way, there are no studies that have been done due to the danger involved in manipulating people under anaesthetic, as joint dislocations are a real danger. To the best of my knowledge, only a select group of people from the fascial research world have looked into it, and by memory it was basically just the therapists themselves volunteering to be manipulated under anaesthetic, hardly a diverse group to allow proper results.

I also think that a study like this while interesting from a research perspective, would do nothing to change the way we approach our practice. The take away from the story is that we should be approaching flexibility training through the nervous system. To have a safely accessible range of motion, we need a couple of things:

1) Strength throughout the full Range of Motion. This is totally a property of the nervous system, and not to do with physical size of the muscle; you just need to walk into any gym, find the hugest guy in the room and ask him to do a german hang to demonstrate this. His nervous system has zero capacity to recruit muscle at the end range of motion, and so they go into full panic mode and think their shoulders are going to explode. It can easily be rectified in the space of about a week or two using particular cues that encourage certain nervous system responses. I can also demonstrate this reasonably easily with just about anyone. Put them in a ROM that they have easy comfortable access to and they should be able to express some level of strength there. The first time you put them beyond this ROM, they will have no capacity to express strength there. My tailor's pose is a good example here, I can easily lift Kit's entire weight through my comfortable range of motion, but it's almost like there was an immediate drop off in my capacity to recruit muscle as I relaxed and it passed a certain position: I had zero strength there at all. Now, after 17 days of training strength in this position, I can do it from a flat position. This position is now getting very easy for me to access as a result. As a side note; have strength accessible right out to wide ROMS has made all movement feel incredibly safe for me.

2) Capacity to relax throughout the full Range of Motion. Again, physical properties have zilch to do with this, it is accessed via cues that encourage particular nervous system results.

My current feeling is that the physical changes that happen in the tissue are happening beyond the access of the tissue in normal motion. Let me try and explain what I mean: Imagine you have a physical capacity (under anaesthetic) to move a limb through 90 degrees. In your awake state you have access to lets say 60 degrees (i just made this number up, no idea what the relation actually would be). As you practice and change the nervous system response it opens you up to say 80 degrees in the awake state, but during that time there have been changes in your physical structures that now allow 100 degrees of movement under anaesthetic. So despite the physical structures having changed (which they obviously do), our new awake ROM is still not beyond our original anaesthetised ROM. I highly doubt anyone has capacity to move to the edge of their anaesthetised ROM while awake, although we can approach it using cues such as Kit uses in his work. At any rate, we are consistently working in the space between physical limits and nervous system limits, so the approach is still the same. I imagine the "padding" between awake and unconscious ROMS is probably pretty different amongst different people, and also different between different joints in the same person depending on their history. Actually thinking about it now, I imagine as you get closer to physical joint (i.e. bone) limitations in your awake ROMs, then the padding would be exponentially smaller. Explaining all of this in class is a huge pain in the ass and doesn't really add anything for people to work on, so the quick story about the anaesthetised person gets the point across and then we can move on to actually doing the work.

Anyone have access to about 1000 people and an anaesthetist to test out my theory?

[Adurst]

I wonder what would happen to

"Prawn Man" if you physically restrained him in the new position till his conscience mind could become full aware again...now in a new range for him.

Overall this mirrors my recent experiments...which yielded minimal if any results, except poor sleep.

[[DW]]

Ha ha! I was talking about restraining anaesthetised 'prawn man' whilst he 'comes to' with someone, not two days past! Unethical, God yes; fascinating, definitely! My bet is his head would explode off, or he would spontaenously combust. I'll get the odds and we can place bets..

[Adurst]

I wonder if the response would be strong enough to rupture muscle or tendon attachment points.

Or would they meld to the new habitat.

[Adurst]

Only unethical if you don't get informed consent first.

[Jim Pickles]

Craig: "I haven't seen any evidence myself of the side splits under anaesthetic thing, although I am guilty of repeating the wives tale that I've been told by many people."

Side splits - and I was assuming it was front splits, and therefore hamstrings rather than adductors would be critical - but the point that there was no perfect flexibility (perfect up to the limitations of the joints themselves) still stands.

"I also think that a study like this while interesting from a research perspective, would do nothing to change the way we approach our practice." I guess as a biological scientist I think that the way forward is to understand the basic mechanisms, and build up from there (a bottom-up approach). But obviously, the critical thing is whether a treatment works or not, which you could call a top-down approach. I think both approaches are needed for a full understanding - and we hope that they will meet somewhere in the middle.

"The quick story about the anaesthetised person gets the point across" - the prawn man story certainly does that, as well as being accurate.

"I imagine the "padding" between awake and unconscious ROMS is probably pretty different amongst different people" - I guess that in highly trained people the padding will be less, and therefore these effects may be less, although they would be better at producing any intended changes.

I am in full agreement with all that section (1, 2 and onwards) of your reply by the way.

Anyway, moving on still, I am also interested in the discussion of "breakthrough" stretches - if we know where, or how, they best occur, maybe we can produce them more often. I am getting the impression from the examples given (and my own experience) that they either involve the inner thigh muscles or some sort of skilled activity - learning how to use the muscles in a new way to produce the desired result. The latter obviously would need the involvement of the central nervous system. The inner thighs are a complex area where many different muscles come in over many different phases of the movement, and also there is a heavy fascial involvement. Maybe this complexity is a reason why we can get breakthrough stretches in that region. If anyone could give any examples from their experience I'd be very pleased to hear.

Anyway, many thanks for your reply, which I have read in detail even though I have not responded to all the points.

[Craig]

Thanks Jim,

RE: "The quick story about the anaesthetised person gets the point across" - the prawn man story certainly does that, as well as being accurate.

I absolutely agree and will use the prawn man in my example from now on

[Kit_L]

Jim wrote

The critical part is that under anaesthesia, we should be able to do a perfect split (1). The critical words are “perfect split”. This is not born out by the evidence I found, nor by your example, which does not address it.

Like so many other examples, this research simply has not been done, so we cannot either find evidence to support it, nor not support it, from the literature. Let's do a Gedanken instead.

We all know that no muscles actually connect the two legs; each side is discrete and the muscles all attach either on the L or the R side of the skeleton in the coronal plane—none spans the gap, so to speak. Everyone can put one leg out to the side (on the back of a chair, say), with the hips level and most people's leg will be near 85 degrees from the midline (as seen from above). This is one leg in the side splits position, or very close to it, so half of the side splits equation. Tom Kurz demonstrates the beautifully in this PDF:

http://www.wushu-tea...ch_yourself.pdf

And repeating this for the other side yields the same results: one leg at a time can be taken to the SS position easily, and I have demonstrated this many times on workshops. His conclusion is that ONLY the neural system controls this position when the second leg is take out to the side in exactly the same way, as we do when we try to slide into SS from the standing position. When I talk about being able to do perfect splits under anaesthetic, this is what I am talking about, but I reiterate, no one has actually tested this, AFAIK. And, clearly, no fascia restriction exists under these conditions. The gracilis/inner hamstring release I do on workshop is only needed when the trunk and pelvis lean forwards from this position (so when going from SS achieved from the standing position, and the body moves forward into the pancake position.

​Front splits, in my opinion, is another kettle of fish completely though, because the back leg's extension is much more dependent on fascial restrictions, based on my own experience. It is a much strong factor in the restriction sense in an older person than in a younger one; these restrictions take a life time to manifest. So, in this position, it is not only the neural system that limits the position. Under anaesthetic, I would expect that the front leg will flex at the hip to the limit of the joints once the brain is disconnected, but I would expect fascial restrictions to limit extension of the back leg, so the back leg would not extend as far (demonstrate the same vastly reduced tension that the front leg will) under the same conditions.

[Kit_L]

Jim wrote:

I am also interested in the discussion of "breakthrough" stretches - if we know where, or how, they best occur, maybe we can produce them more often.

I am too (of course); I have one that has made a tremendous difference to my legs apart stretches and forward bending generally. I want to video this over the next little while and post, here and on YT and FB. Stay tuned.

[Geotrismegistos]

I am too (of course); I have one that has made a tremendous difference to my legs apart stretches and forward bending generally. I want to video this over the next little while and post, here and on YT and FB. Stay tuned.

Cant wait

[Jim Pickles]

Kit - many thanks for taking this one up again - I was going to let it drop, but will give a proper reply (in a later posting when I've done some measurements).

Kit and I have previously discussed the straddle example, with differing conclusions. I will take some measurements and show some photos in the next few days which will - or will not - support my view (that once the rotation, tilt and twist of the pelvis is taken into account there is no difference in flexibility between one leg at a time and the two simultaneously - at least in me). Please wait a few days for that.

By the way, in his PDF, Tom Kurz (who is not only of course very highly trained, but CAN do a perfect straddle split) has his hips tilted (as shown by the positions of his hands in his first figure) when he has his leg up at 90 degrees on a chair (and we can't see how much they are rotated towards the back either). And the closer you are to a perfect straddle, the smaller any rotation/tilt/twist of the hips will be, and the more precise any measurements will have to be to show an effect, if it exists.

"I would expect that the front leg will flex at the hip to the limit of the joints once the brain is disconnected" - this is what was tried in the experiment by Krabak and colleagues that I quoted - and they found no effect of general anaesthetic - the leg stayed where it was before (with very modest flexibility indeed - a popliteal angle of around 130 degrees when the thigh was at 90 degrees to the torso).

Much as I would like to think that (until the limits of joint integrity are reached) the nervous system is the ONLY thing affecting our flexibility – after all, the nervous system is a highly modifiable part of the body and its job is to adapt rapidly to the environment - I cannot see that this is born out by the evidence. Hence my emphasis on this, because it helps direct where we should be putting our attention in our training.

By the way, I eagerly await more info on the breakthrough stretches - it would be nice if we could generate these more often.

Cheers, Jim.

PS I hope you don’t mind these challenges, As a scientist, I see the value of the dialectic.

Edited later at 18.40 EST to clarify a few points, but not change the sense.

Edited October 30, 2014 by Jim Pickles

[SwissDanny]

It seems in other areas (language, visual perception etc) a lot of insight is gleaned from people who have say had parts of their brain removed due to tumors and the side effects this can lead to. Is there any literature out there that covers cases of mobility increases following brain trauma. I guess paralysis, spasticity and or lack of motor control etc are extensively referenced, but I was thinking more of rarer cases of say sudden dis-inhibition of range of movement? Just a thought.

[Jim Pickles]

I've done some measurements to test the point that I made above. I thought I'd take some photos too for added validity, and usually find it easiest to take photos off a video. Then I thought why not make a video of the whole thing. So here it is, on Vimeo (the first few seconds are silent, so please persevere):

The conclusion - in me, two half-straddles done separately completely explain the flexibility in a straddle done with two legs at once. There is no sign of any extra "neural" - or any other - component.

Please note that Tom Kurz says "Stand beside a chair or table and put your leg on it as shown below. Make sure that both your hips and your raised leg are all in one line". This of course begs the question - if you can get your leg out at right angles and it is EXACTLY in line with your hips (i.,e. the hips are not rotated or tilted sideways AT ALL) then this is the flexibility (in one leg) needed for a perfect straddle split. I would not be surprised if people who can do this can also do a perfect straight-line straddle (but it needs to be tested). What I showed was that AS MOST PEOPLE DO IT, there is a considerable rotation of the hips, and this explains entirely why I at least cannot do a two-legged straddle, even if we can apparently get our leg out to the side. Clearly, the more flexible someone is, and the closer someone is to a perfect straddle, the smaller any critical differences are going to be, and the more precisely any angles will have to be measured.

If you think my measurements look a bit scrappy (1) I have done it 4x with exactly the same results, and (2) any errors in angles and positions of measurement would be trivial compared with the 40-45 cm that we are dealing with.

If anyone else would like to do this, you could see if it applies to you, or whether I am just a strange case (but I think I'm not).

As I said, the video was intended only as a record for photos, but once I'd started, I thought why not make something for other people to see. It was done in a short time, and was not intended to be of high quality. I learned a lot about making a video in such a short time - and my admiration for the very high quality of Kit's videos has gone up stratospherically as a result!

Cheers, Jim.

Edited November 13, 2014 by Jim Pickles

[Geotrismegistos]

Great video Mr.Pickles. I did a similar check now, though without the equipment you use, and i found similar results. Both legs, and one at a time seem to have similar range of motion.