Sherlock = Delayed Stabbing ...?

[joko]

is this possible? or likely?

i get that a tight belt would keep the wound closed, and stop the bleeding - but as with a tourniquet it would need to be quite tight - the belts are just worn as a uniform they are not 'functional' as holding anything up or closed so surely wouldn't be worn uncomfortably tight, as what would be the point?

assuming the weapon has to be a very thin spike - as a blade would cut the belt, or the fabric of the tunic - how thin would it have to be that you didn't even feel it?
i mean, you cant get much thinner that a syringe needle and you can feel them ...!
though, i suppose if you did feel it, you may just think it was a cramp or something ...

also even if the person was stabbed deeply with a thin prong - when the belt was removed, a wound that thin wouldn't 'pour' with blood so fast that the person didn't notice and didn't have time to deal with it...would it?

so whats the deal here - am i missing something?


NB - i KNOW this is just a TV show, but i'm curious as i assume there is supposed to be some medical knowledge etc with the story ...?

cheers

[ludwig]

I thought it was a bit too unrealistic as well, but you know, it's just entertaining hokum.

[wolf63]

I didn't watch the programme but people have been known to be unaware that they have been injured due to shock. :-)

[joko]

i've heard that wolf, but in this instance there was no shock as they supposedly were unaware they were even under attack - as someone sneaked up on them, stabbed them with this spike an they didnt even notice

one was a guard outside buckingham palace, so was used to the public being near him but unable to look around etc

[woofgang]

Not sure about stabbing, but if you are concentrating hard, its possible to cut yourself quite badly and not feel it or notice. I was helping a friend assemble Ikea furniture recently and didn't notice the cut until it was pouring blood all over the place!

[bednobs]

i think the points you make are valid JOKO, but as with any ficton, you just have to suspend disbelief. For example, i could not understand why the culprit would chose someone else completely unrelated to kill, just to practice what to do, just because he had a grudge against the wonky face man. I also coudn't understand why the man who he practised on didn't have his belt examined when they realised he had been stabbed. Hey ho, it didn't interrupt my enjoyment tho!

[jno]

yes, the point about Sherlock Holmes from when he was first invented was sheer logical plausibility; it's a shame to stretch that

[FredPuli43]

Victims of stabbing, unless they see the weapon being used, invariably say that they thought they had been punched. That's because we haven't got the nerves inside us to tell us we have been wounded. We have them on or near the skin and the person feels the impact as a punch.

[woofgang]

The killer needed to test his theory on someone else who would be dressed the same (tunic and tight belt) would be used to being stoical in crowds and not reacting to being touched or pushed, even quite hard. Part of the point was that the killer had no compunction whatsoever about using a complete stranger in this way.

[Legiononomamoi]

1) What is the underlying physiology of “pain”?
Detailed Answer:
The kind of pressure experienced by a “touch” activates nociceptors (“pain” receptors). However, we don’t experience it as pain because of various mechanisms in pain modulation. Instead, we just feel it. If you put on comfortable clothes, you feel them initially but the primary nociceptive cutaneous fibers quickly desensitize and after a bit you can’t even feel that you’re wearing anything. Tapping someone, on the other hand (tonic pressure) activates nociceptive pathways that mechanical stimuli do not. Thus “pressure” can activate both the nociceptors that stabbing can and those that it cannot. A belt that is stiff, tight, and covering so much area is easily a noxious stimuli that becomes more painful as time goes on (imagine carrying a heavy bag- as you move it impedes your movement via the same mechanisms that make it uncomfortable to start with and coming in contact with your skin in a non-continuous, semi-tonic manner).

Summary: The perception of “pain” can result from two different kinds of sensory experiences. One includes everything from stabbing to poking to chemical burns. The other includes only a kind of constant “pressure” like being tapped repeatedly or wearing an uncomfortable belt for a long time. An uncomfortable belt can be experienced as the kind of pain that stabbing is, but also as a kind stabbing can’t.

2) How can wearing a tight belt prevent one from experiencing being stabbed?
Detailed Answer:
The “silent nociceptors” that are sensitive only to tonic pressure are mostly found in joints, but they are also common to the viscera. Such deep tissue pain is less inclined to subside and is not localized the way cutaneous pain is. Even if a belt were not intense enough to activate visceral “silent nociceptors” they are in joints like the spine which is pressed right up against the belt. Being stabbed, on the other hand, can’t activate either visceral or any other deep tissue mechano-insensitive nociceptors as it is a mechanical stimulus. The same nociceptive fields that are activated and modulated by the belt are those that the knife affects. If one were to put on such a belt after experiencing tissue trauma to some region the belt covers, one would feel increased pain (as hyperalgesia accompanies tissue damage). However, the same modulation processes that occur from wearing a belt that 1) is noxious just by being too tight and 2) is not applied continuously thanks to motion (making modulation more complex) and finally that is activating mechano-insensitive nociceptors will require a much more noxious mechanical stimulus to experience any sensation. Stabbing can do this through tissue damage if it e.g., damages afferent neuronal axons, but like everything in living systems and particularly within neurophysiology we are dealing with complex networks interacting in complex ways. Simplistically, the pain pathways that would be affected by tissue damage-induced hyperalgesia are already active, so indirect activation of peripheral afferent nociceptors STILL has to be transmitted through the CNS. As the modulation or changing of responses to afferent neurons begins at the spine, and the deep tissue nociceptors in the spine itself can be activated by the belt, it becomes a lot harder for a local, peripheral noxious stimulus to be experienced as such EVEN if it is experienced. Add to that the general effect of constricting blood flow, the behavioral influences on pain networks, a general arousal a recluse who receives constant death threats might experience setting foot in a public setting, etc., and you have a great combination of processes influencing the ways in which sensation is possible in general let one in an area covered by the belt. The main mechanism would be through peripheral nerve damage, but that’s exactly what a thin, fine blade avoids.

Summary:
If you’ve been carrying a heavy bag filled with bricks while jogging that continues to poke