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The hydrostatic shock theory?

Discussion in 'Handguns: General Discussion' started by Pyro, Sep 5, 2011.

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  1. THplanes

    THplanes Member

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    You can't talk about blood vessels as if they are all the same. Veins are low pressure and have valves. Arteries are high pressure and don't have valves. Arteries are designed to move blood efficiently. They're not designed to dampen BP. If you hold your upper arm and wrist at the same level, there will be very little difference in BP.

    The lungs dampen the transmision of the pressure produced by the TSC to the major vessels in the chest. Once the BP spike occurs the lung do nothing to dampen it.



    I have a few questions for the Fackler camp that I can't any other Facklerite to answer, so I'll try you.

    1) Are there any lab animal studies that show shots in the extremities show an increase in intra-cranial pressure. For those that don't know, BPW's proposed mechanism is by increase in intra-cranial pressure.

    This is really a rhetorical question. There is a study done on anesthetized dogs shot in the thigh that demonstrates this to be a fact. There are also at least 2 other studies that show an increase in pressure at a location remote from the wound site. That BPW exists is a fact. Since these studies were done on anesthetized animals, the question of at what, if any, point does the pressure increase hinder an individuals ability to function is left open.

    2) Fackler holds the view that any rapid incapacitation can only occur by
    a) CNS damage
    b) psychological incapacitation.

    The question is, where are the psychological studies that back this up.

    3) Fackler seems to make the claim that psychological incapacitation is independent of caliber, at least within the realm of service pistol calibers. Doesn't matter if it's a FMJ 9mm or a 125 gr SJHP .357 mag.

    Where are the psychological studies that back this up.
     
    Last edited: Sep 10, 2011
  2. THplanes

    THplanes Member

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    How?

    There are no large diameter blood vessels in the neck. The large blood vessels are in the chest. It's similar to this. If you take a 1/8" inch hose and rapidly collapse 3" of it, what happens to the pressure in the rest of the hose. On the other hand, what happens if you take a 1"x 3" tube with a valve on one end, 1/8 hose on the other and collapse a 3" section of the 1" hose. The volume of the tube being compressed makes a big difference.

    Are all forms of mild traumatic brain injury detectable by X-ray or CT. Do you need to see hematuria in order to diagnose mild TBA.

    Since there is a limited volume of blood in in the major vessels in the chest, this limits how much pressure change can occur. It's not an unlimited change in pressure, it's limited by the volume of the major blood vessels.

    Second, you don't find what you're not looking for.

    http://is.muni.cz/th/132384/lf_d/?furl=/th/132384/lf_d/;lang=en
     
  3. THplanes

    THplanes Member

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    Yes it's unreliable, there are a number of factors that probably change how effective it is. Here are few obvious candidates:

    Stomach and intestinal contents
    Percentage of lung inflation
    Where your actual BP is on the systolic-diastolic curve
    Loss of elasticity of arteries
    Some people just not susceptible to it ( I've seen people you'd swear a 2 year old could KO. I've seen others that the incredible hulk could take a telephone pole and knock them 2 blocks and they would come back and plant that pole in a dark place.)

    This is why you'll find most people that believe BPW has an effect, including Dr. Courtney, advocate choosing loads that will get whatever level of penetration makes you happy first. Choosing a round with a high BPW is a secondary consideration.

    You don't need to render your opponent unconscious to gain an advantage over them. Something as simple as mild confusion may hinder their ability to fire accurately and fast.
     
  4. armsmaster270

    armsmaster270 Member

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    Instead of all the formulas try this Click on picture to start

    th_BallisticEffects.jpg
     
  5. JohnKSa

    JohnKSa Moderator Staff Member

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    I don't believe that necessarily follows.

    In order for the ballistic pressure wave to form and propagate, the energy from the projectile must be coupled into the body. If the structures in the neck don't lend themselves particularly well to this type of coupling effect by which the energy from the projectile is transformed into a pressure wave, but the structures of the chest or trunk do, then it could be reasonable for a bullet striking the trunk to create more of a ballistic pressure wave effect in the brain than one striking the neck.
     
  6. Odd Job

    Odd Job Moderator Staff Member

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    THPlanes says

    Carotid arteries x 2 and vertebral arteries x 2 are not enough? Have you checked the diameter of those and factored in that there are four of these vessels? It seems Michael Courtney himself would disagree with you about the value of those vessels: the aforementioned maxilla and neck injury in the Treib paper he cited was in Zone 3 of the neck. Too bad he didn't get the trajectory checked though.
    If those neck vessels aren't good enough, I suggest you find whatever large vessel you are thinking of (in the chest) and trace it from point of impact to all its branches. If you compress the ascending aorta you cannot expect that displaced blood to act only superiorly and only in the brain. There are many branches on that aorta!

    JohnKSa says:

    That's a slight deflection: do you subscribe to the notion that the vessels are the conduit for this pressure wave or not? Difficult to discuss your point otherwise.

    THPlanes asks:

    This is a side-step.
    My comment was about the propogation of this ballistic pressure wave in all directions. If we are to entertain a theory that relies on the transmission of a wave through the vessels from the chest to the brain, we have to also ask where the effects of that wave are seen inferiorly. Where is the damage to the fine nephrons of the kidney (whose position and access in vascular terms would be more ideal candidates for damage via your pipe analogy than the brain)?


    THPlanes says:

    Well, that's convenient, isn't it (if you actually believe it). I don't buy it, but I appreciate the value of that arguemnt as a loophole when the facts encountered in the ER get in the way. I can just see it now:

    "The subject was too small to have sufficent blood volume for this wave to produce the effect"

    or

    "This was a borderline case where the effect was not seen because the shot happened in diastolic cycle."

    THPlanes says:

    It is you who don't look. Here is my comment on that link in the GT thread I referenced (I think you knew about that thread anyway because you POSTED in it):

     
    Last edited: Sep 10, 2011
  7. Loosedhorse

    Loosedhorse member

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    Thanks, TH. I did cover that in post #31 (and others did elsewhere), but I think your answer is particularly clear. Sometimes it helps to see the same info presented different ways, and so maybe now we've finally disspelled the "If that were true, your palm would suffer as much damage as the target" nonsense.

    Separately, the idea that compressing a larger--aorta--vessel should produce more cerebral effect that collapsing a smaller--carotid--one hadn't occured to me, because I didn't consider collapse of large vessels as occuring in response to a BPW. It prompts the question: do we know that radial compression of the aorta is how ballistic pressure waves are produced?

    JohnKSa, the idea of optimal energy coupling is important, too.

    It's a nice discussion, folks--thanks!
     
  8. THplanes

    THplanes Member

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    No, we don't know that for sure. Most of the ideas about the mechanism are more theory than anything else. We do know factually that dogs shot in the thigh show an increase in intra-cranial pressure. That's really about all we know as hard factual data.

    I had a response to Odd Job just about done and it timed out one me. I'll redo it later today.
     
  9. MachIVshooter

    MachIVshooter Member

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    I'd like to see the rest of the vitals that went along with that. General anesthesia does not render the parasympaythetic nervous system non functional, so the increased BP and cranial pressure could have been caused by increased heart rate with adrenal response to the injury.

    As well, I don't think any of us are arguing that bullets passing through bodies create pressure, just that it isn't a wounding mechanism. Sneezing (among other less pleasant bodily functions) also increase pressures, but unless a person is medically compromised in other ways, these normal body functions don't cause a crippling disruption of the nervous system.
     
  10. Loosedhorse

    Loosedhorse member

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    General anesthesia suppresses brainstem function, which is why an artificial respirator must be employed. So, general anesthesia would prevent a brainstem-mediated general (endocrine) release of adrenaline into the blood, or other brainstem-mediated changes in blood pressure.

    The intracrainial pressure rise that was talked about in the dog experiment is, I believe, transient, beginning and ending with the passage of the bullet. Endocrine and brainstem-mediated changes in BP cannot begin and end that fast.

    Atropine, a parasympathic blocker, is typically given during general anesthesia--I do not know if it was given in this case. The release of adrenaline into the blood is actually part of the sympathetic system; there are also sympathetic blocking agents widely available, though again I do not know if they were employed.
    There is extensive literature on sneeze syncope, cough syncope, weight-lifter syncope, brass-player syncope, etc. As you say, they affect just a few people.

    A typical cough generates up to 5 psi of transient pressure in the thorax. The Coutneys specify 1000 psi as their BSW entry level. We might suppose that if a few patients are affected by a 5 psi transient, then many more would be affected by one 200 times greater.
     
    Last edited: Sep 10, 2011
  11. brickeyee

    brickeyee Member

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    The water is very efficient at transferring movement and energy.

    While tha can full of air may contain the blast, a can full of water may burst.

    Even shot at cans full of water?

    Even a .22 RF can often manage to split the thin aluminum.

    An empty can may not even move when hit sometimes.

    A shot a beer can full of water once at 100 yards with a .30-06 with a 150 gr bullet.

    It made an instant cloud of fog.
    The can was blown into shreds, with the bottom formed and sticking to the rock the can was sitting on.

    Empty cans just go flying.
     
  12. Cop Bob

    Cop Bob Member

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    I think that what has taken place in this thread is basically a whizzing contest over the DEGREE or AMOUNT of hydraulic shock, or hydraulic energy transfer..

    Agreed, Rifles do far more TISSUE damage as a result of HYDRAULIC SHOCK because of the combination of weight and speed, and penetration..

    Handguns have far less CATASTROPHIC TISSUE DAMAGE because they lack the speed required to produce the larger shock wave that high velocity rifle rounds do..

    But BOTH produce a HYDRAULIC EFFECT WITHIN A BODY...

    Where folks seem to be argueing is on the DEGREE or AMOUNT of hydraulic shock that is transfered or delivered..

    Understand, that in a SD handgun round, we are looking for sufficient energy transfer to cause an IMMEDIATE disruption to the CNS to cause a a rapid, or immediate incapacitation.. Temporary of permanent, we will take either.. as long as it ends the fight quickly and to our advantage.. Unfortunately, to effectively do this with any hope of reliable and predictable desired effects, round or shot placement is critical... and to insure the desired effect, the rounds must me aimed at areas that also will result in death.. Center mass, or "the Fatal T".

    While veins and arteries are conduits for blood, (fluid) throughout the body, the body is approximately 86% water. COmposed of blood, bile, and a host of other aqueous compounds, all that will act to transfer energy to a varying degree. the amount of fluid moving through the vascular system as a result of a bullet impact would be minuscule in relation to the wave that is moving through the body via the flesh and organs.. I think that we can all agree that abdominal areas are more aqueous than muscle, and that the facial area is loaded with sinus cavities that are mostly air, and therefore compressive and less likely to transfer hydraulic force.

    This could explain why a rifle round across the front of the face would not destructively disrupt the brain.. I too have seen similar effect in a shooting victim with a 30-30, his brother managed to blow his lower jaw off, along with most of his tongue, and a few teeth out of the upper mouth, but he was alert conscious and oriented in the ER.. He was able to write us as to how stupid they were... I wish a had kept some of those pictures. Lower jaw area, bone, muscle and air.. little to transfer energy... But man it looked like it hurt!

    It does not take a huge, flesh tearing, explosive force to render a person unconscious, or to cause their central nervous system to temporarily short circuit.. If would be interesting to see an EKG and an EEG of an individual at moment of impact of rounds of various types and placement.. but I would bet that the universal trait would be the EEG would go off the charts... The only question would be how far off the charts and for how long..

    I think that everyone here agrees, that a hit from a 9mm is nowhere near as bad as a hit in the same spot from a 7 mag.. and I think that we all agree that a head shot with a 158gr 38, would not be near as "graphic" as a head shot from a 168 gr .308.. but the victim would be just as dead... for you see, as many bodies as I have viewed in my lifetime, I have never seen varying degrees of dead... it is only a matter of how fast they got there.. dead is dead...

    However not everyone, or thing that absorbs the impact of a bullet, goes down immediately, that is just not the real world.. So what we all seek, is a round that will take as much ability to fight, or take flight in the case of game, as possible... This is done, in handguns, through the use of good hollow point ammunition, pushed as quickly as it can safely be... or in the case of rifles, with Soft Point or other expanding ammunition.. We seek antiquate penetration so that the maximum transfer of energy takes place along the entire length of the deepest wound track we can generate, and ideally not exiting the body, for both the maximum effectiveness of the round via energy transfer, and the liability reasons of the possibility of collateral damage.. This is why we chose different bullet weights for different game, or applications..

    I think that we would all agree, that ether we are hunting or going into a combat situation, that we would be loading with the best rapid expanding handgun ammunition, or SP, or ballistic tip rifle ammunition we could get our hands on.. Why, because we want that, however tiny or catastrophic it may be, edge of hydraulic forces working for us...

    But I too, am still looking for that .22 or 32 caliber pistol round that has no recoil, cannot miss, and has the terminal ballistics of a harpoon missile.. when they come out with that, somebody left me know.. I want two!
     
  13. MachIVshooter

    MachIVshooter Member

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    Brainstem controls much of our involuntary function, reaction and reflex-but not all, and some of those functions can be/are controlled by the Vegas nerve in the absence of spinal cord function. There are also many people who experience varying levels of consciousness during sedation from general anesthesia. The nervous system is really very little understood.
     
  14. brickeyee

    brickeyee Member

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    They have not been given enough.

    It is a real problem sometimes.

    Even with supported respiration (patient on a ventilator) the ling between anesthetized and dead is very fine.
     
  15. 481

    481 Member

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    Odd Job,

    An excellent and broadly comprehensive perspective. Your posts always make my head hurt (in a good way :D ) and the information you've passed on is an education in itself.

    Thanks.
     
  16. Odd Job

    Odd Job Moderator Staff Member

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    That's it, exactly!

    On a similar note, I can say with certainly that there IS damage to tissues that are not in the direct path of the bullet in certain circumstances. I have seen it myself in only a handful of cases...BUT in all instances the damage has been within an inch or two of the bullet track.

    The best case I saw was a gunshot liver that resulted in a spectacular stellate tear of the liver capsule and marked cavitation of the liver tissue beyond the size of the bullet. That can be partly explained by temporary cavity exceeding the limits of the liver's ability to yield. It is not elastic.

    In another case I saw a subclavian artery intimal flap from a posterior to anterior GSW of the upper chest. There were multiple fractured ribs also, these were in the path of the bullet but the subclavian artery was not (although it was close). The intimal flap was found by angiogram after radial pulses were not equal when comparing right to left.

    In the case of the liver injury you could argue that the cavitation contributed to the severity of the wound, but in the case of the intimal flap this is not the case.
    There have been documented cases of fractures to delicate orbital plates from intracranial GSWs but that is to be expected if you have an enclosed space where there is no pressure release. So those are a special case.

    Malcolm Dodd has published a nice atlas on gunshot wounds, it is called Terminal Ballistics and it can be bought online:

    http://www.amazon.com/Terminal-Ballistics-Atlas-Gunshot-Wounds/dp/0849335779

    Some very useful info in there, I bought my copy some time ago.
     
  17. brickeyee

    brickeyee Member

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    The body knows how to cope with them, bullets, not so much.
     
  18. gamestalker

    gamestalker member

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    Hydro static shock if no myth. I've killed a lot of big and small game with high powerd rifles and the type of damage created by liquids not being able to disperse is daunting. I once shot a coyote with a .270 hand loaded 90 gr. HP and the coyote litterally exploded into the the under side of the tree he was standing under. No exageration here, that dog was litterally unrecognizable and completely disenegrated. And jack rabbits, well just let me say that there is no more than fur and blood left.
     
  19. JohnKSa

    JohnKSa Moderator Staff Member

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    It's not a deflection at all.

    Wires are excellent conduits of electricity, but wires don't necessarily make good antennas unless they're specially constructed to couple well to radio waves. In a similar fashion while the blood vessels in the neck might be reasonably good at conducting the pressure waves from the torso to the brain, it might be difficult to couple the pressure waves directly into them via an impact to the neck.

    In other words, the torso has a lot of tissue types (and a lot of tissue) not found in the neck. Those tissues and tissue types might be required to couple the pressure wave from the bullet into the blood vessels. Once the pressure wave is coupled into the blood vessels they could act as the conduits to move it to other parts of the body.

    The neck is a structure mostly composed of bone, blood vessels, muscle and connective tissue. It seems somewhat reasonable to assume that the torso, a region filled with a lot of fluids and soft tissues, might couple bullet energy more effectively into blood vessels.

    I'm not trying to rigorously defend a theory here, I just think it's worth pointing out that coupling the energy into the vessels in the first place probably requires more than just having a bullet pass close by. It might require having a bullet pass close to a vessel that's surrounded by certain types of soft tissue that allow the energy of the projectile's passage to be readily transferred to the blood vessels.

    All of that to say, I don't think it necessarily follows that a bullet strike to the neck would automatically create a more significant pressure wave incident in the brain than a bullet strike to the torso.
     
    Last edited: Sep 10, 2011
  20. Mike1234567

    Mike1234567 member

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    * deleted *
     
    Last edited: Sep 11, 2011
  21. Odd Job

    Odd Job Moderator Staff Member

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    JohnKSa says:

    That's an interesting theory. The dependance of tissue types or the presence of different tissue types can hurt the theory also. In the torso the lungs won't be a good material for the propagation of a pressure wave because of air spaces in the alveoli. The shot then has to be confined to the mediastinum below the level of the apex of the arch of the aorta. You may as well confine it directly to the heart and major vessel roots if that is the case.

    Another way to get at the answer then is to ignore the head and look only at the abdomen. If a ballistic pressure wave from the chest can affect the brain, then it must also affect the abdomen, specifically I am interested in the kidneys.
    If that shot is then compared to a sub-diaphragmatic shot, then we should expect to see more overt features of fine vessel damage in the kidneys or maybe even the liver (assuming no direct hits of either, to confound the issue) from the shot to the upper abdomen.

    I just haven't seen it.

    I have to go by what I and my colleagues have seen up close in the ER over the years. All those trauma patients get a micro urinalysis. I would be expecting two features then:

    1) A significant number of positive haematuria cases from GSWs to the chest (with no other aetiology).
    2) A significant and greater number of haematuria cases from GSWs to the abdomen (with no other aetiology and no direct strike to the urinary tract).

    Somebody needs to show me the evidence for that, because I haven't seen it and I have seen several thousand GSWs in person. Not journal cases from the 1940s, but real acute cases in the ER.
     
  22. brickeyee

    brickeyee Member

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    But ANY wire couples SOME energy in an RF field.

    Efficiency is not the issue here.

    The ability to couple AT ALL is the issue.
     
  23. Loosedhorse

    Loosedhorse member

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    The vagus nerve originates in the brainstem, so anything that suppresses the brainstem will suppress the vagus nerve. The list of its functions is easily found. Yes, since the vagus is not in the spinal cord, it can function in the absence of a spinal cord--although such a patient will not be able to breath without spinal cord function!
    As has been said, only if they are not really under general anesthesia at that moment. There is no consciousness when actually under general anesthesia.
    There are many remaining mysteries about the nervous system; I already mentioned the questions regarding concussion syndromes. However, what any one person thinks is "not understood" about the CNS might more reflect what he doesn't understand than what is actually not understood. Further: any mysteries go more toward causing us to consider novel theories of incapacitation, as we do not have sufficient knowledge to exclude them.

    Finally, what does any of your comment have to do with arguing against the BSW theory? I begin to wonder if you are just making inaccurate human physiology statements on purpose, to taunt me into correcting them? (Vegas nerve, indeed! :rolleyes: Have you no shame?)
    Are the Courtneys alleging microhemorrhage in the CNS as a result of BSW? If they are not, then why would we expect microhematuria? Even if they are, it could be argued that the structure of the kidney (including its vasculature) is enough different from the CNS that a BSW produces microbleeds in one system, but not the other.

    So, either way, I'm not sure on why I should consider the kidneys as being able to disprove the BSW theory.
     
    Last edited: Sep 11, 2011
  24. Odd Job

    Odd Job Moderator Staff Member

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    Yes he did. He proudly referenced the student Czech paper for that purpose.

    We have no evidence of either case producing micro bleeds, so I guess if it comes to a comparison like that which seeks a definitive answer, the proponent of the theory will just have to do some tests/experiments to prove it. The onus isn't on me to disprove it, it is on him to prove it. He could have done it a long time ago with animal experiments but elected not to. Obviously an element of mystery is more commercially viable than outright failure.

    Because they are delicate organs with very fine vasculature and unimpeded arterial access. If people can frequently have haematuria after extra-corporeal shockwave lithotripsy then I don't see why they can't have that from a ballistic pressure wave.
     
  25. Loosedhorse

    Loosedhorse member

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    What? Why in the world would it be surprising that ESWL produces hematuria? And why would BSW be at all simliar to ESWL.

    People undergoing ESWL already have renal lithiasis: crystaline stones in the calices or ureter--good reason for hematuria already! A total of perhaps 2000 shockwaves are delivered with a total energy of perhaps 150 Joules (both figures are sometimes exceeded). That's about 110 ft-lbs, delivered to a focal volume as small as 450 cubic mm. If successful the lithotripsy breaks the calculus so that the pieces (and their sharp edges) pass through to the bladder, we have more reasons for blood in the urine. If slightly misaligned, the energy is not delivered to the stone, but to the adjacent renal structures.

    So why shouldn't there be bleeding? Heck, there are sometimes renal hematomas after ESWL! But why should we presume ESWL is anything like BSW? My guess is if you focused ESWL enrgy at the surface of the brain, you could produce red blood cells in the CSF--but so what?

    One thing that ESWL does teach us about the theory of BSW? ESWL is only possible because shockwaves propagate through the human body with minimal loss of energy; that seems to be a mark against the idea that the shockwave is "dampened" as it passes through tissue.

    (If I have perhaps misunderstood, and you mean that ESWL of gallstones routinely leads to hematuria, then I apologize for my foolishness. If I have not misunderstood, then perhaps I must pass the fool's cap along...;))
    Ah. Thanks.
     
    Last edited: Sep 11, 2011
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