The difficulty in determining DCS – Anatomy of a Dive Accident

[Ayisha]

Hyperextending the back is definitely not a good idea. I find that many GUE divers just stretch out, myself included, not hyperextend.

It's harder to have "pretty" trim without hyperextending the neck, but you can extend the neck just a little.

Most divers don't spend multiple hours hyperextending their neck during diving, let alone competitive cycling, let alone competitive cycling/training followed by diving the next day.

 

[chillyinCanada]

As it happens, when you start looking into Cervical Stenosis.....pain between the shoulder blades which then spreads, is a primary way this presents.

I have arthritis there, which was discovered when my neck and spine were MRI'd.

 

[Pebbles Photo]

So Dan is still hyperextending.

At this point we need to be sure we are talking about the same thing....that the semantics does not defeat the discussion. Dan likes to swim at Suex Scooter speeds with big monster carbon fiber freedive fins, for an hour at a time. to do this, he needs to have his body in a flat horizontal trim like a dolphin would, or like a torpedo would. Of course, with his dolphin kicking when he does that, there is an oscillation at the waist where the lower back moves vertically up and down to drive the legs something like what a dolphin will do....and this means the neck will go from less hyper extended ( to see where he is going) , to more hyper extended. So Dan get's some motion in his cervical area that helps to prevent the damage that constant and non moving hyper extension would cause in a straight hour of dead flat horizontal trim for frog kick, where you want the body to coast maximally after each big push off from each frog kick. It has to be a straight line, and so this horizontal position forces the diver to change their head position from horizontal ( meaning they would only see straight down into the sea floor directly below them) , to one where the body stays flat but the neck is hyper extended so that the diver can see what is directly in front of their travel forward. I don't call this hyper extension of the back---neither Dan nor I feels any stress on our backs in this propulsively efficient kind of trim....we kick and we glide, and our bodies are very relaxed. With freedive fins, the frog kick glide is enormous, and Dan can do this kick and glide faster than most scuba divers can flutter kick. But still he has to have his neck pulling his head up at the most extreme angle it is capable of...It has not caused him any negative physical issues yet, from when he does this, but now after my incident, he is re-thinking the intelligence of this kind of swimming durring times when he does not need to be near the bottom, and when he does not need the extra speed or efficiency....but since he is addicted to speed and efficiency and to his freedive fins, what he thinks is smartest may not get the traction he is saying it will....he might just say he should dive more like I will be, and then keep on doing exactly what he was doing before

 

[Pebbles Photo]

Hyperextending the back is definitely not a good idea. I find that many GUE divers just stretch out, myself included, not hyperextend.

It's harder to have "pretty" trim without hyperextending the neck, but you can extend the neck just a little.

Most divers don't spend multiple hours hyperextending their neck during diving, let alone competitive cycling, let alone competitive cycling/training followed by diving the next day.

I am sort of an exaggeration of issues, no doubt. While our boat dives are only an hour each, I dive a few days each week at the BHB Marine Park, where the shallow macro area gives me dive durations between 3 hours and up to my longest ever at 6 hours, on a steel 100. This has always been diving near the bottom, and when swimming it is in the GUE position, frogkicking. However, when I am taking photos or looking for Nudibranchs in hydroids, I am no longer swimming and the neck stress is less...with some breaks. Still the camera is out in front of me, and even with the 45 degree angle macro view finder, a 3 to 4 hour average length dive here will add up to lots of neck hyper extension. If I was 30 years old this would not be a discussion we would have...but now in my 60's, neck health get's compromised by doing things that are bad for it. Still enjoying competitive cycling has not helped my neck either, as you pointed out. I don't think I would have had the flare up on the dive in question, had I not done the extremely intense and long ride the day before. I am sure my neck was trashed from it....But on this front, the moral to the story is to find the best bike fitter you can, and be sure you are in the smartest bike position you can be riding in....We found this shop in Boca called Racers Edge, with a guy who is almost a "Rainman" of how to get the perfect fit. He considered the position my bike was set up in when I arrived at the shop a "train wreck", and made such massive changes that riding does not feel anything like it did before. So this complication for my neck, will be much less of a complication in the future. With all the new exercises and positional changes, there is a real chance my neck will get so much better that it may be again where it was 2 decades ago in durability for my adventures
Oh...and if anyone wants to know what could possibly get me to want to do 3 to 6 hour long dives at the Blue Heron Bridge Marine Park, visit my page at Sandra Edwards and scroll down a few dozen posts to see the macro wonders we get so excited about at the Bridge all the time, consequences be damned

 

[Jcp2]

The chronic version of surfer's myelopathy is surfer's neck. One is a pinch and a kink of arterial flow, the other is chronic tightness and shortening of posterior neck muscles, leading to bone spur formation that can pinching of the spinal cord. Maybe we should come up with scuba neck, from being too trim of a diver.

What is Surfer's Neck?

 

[scubadada]

...I dive a few days each week at the BHB Marine Park, where the shallow macro area gives me dive durations between 3 hours and up to my longest ever at 6 hours, on a steel 100...

Hi Sandra, That's probably the lowest RMV I've ever heard of, likely <0.2 cu ft/min

 

[Pebbles Photo]

Hi Sandra, That's probably the lowest RMV I've ever heard of, likely <0.2 cu ft/min

It was in fact a high tide, to high tide dive !! But to make it more understandable, if you look at the macro I shoot ( on my FB page), you typically find this life by slowly peering at what it "eats"....You get on top of a large hydroid forest ( looks kind of like a big grass lawn ) and you are essentially lying down on it carefully, with extreme care to not silt or interfere with the bottom....and it may take ten minutes to see every strand of hydroid in one square foot to a certainty there are no good photo subjects within it. When done, you move on to 12 inches further in some direction. You have been to this hydroid forest a thousand times before, so you already know what paths you will take, and you waste no time or effort in moving along your search. I literally do this at my lowest resting heart rate possible for me, which as a competitive cyclist, is extraordinarily low anyway on land...but potentially even lower underwater with Mammalian Diving Reflex kicked in. I can do 45 beats per minute on land, pretty much when I want to. Slow bike rides would be at 80, max HR for a recovery spin ride is 125.....Aerobic zone is from about 145 to 160. Anaerobic Threshold is between 165 and 170 depending on glycogen levels and the wind( cadence and torque related). Max HR was 182 last time I did a full tilt 25 mile time trial ( max HR on the last 30 seconds of this maximum exertion hour long approximate event). Full disclosure....my 100 steel tanks often get "jacked" a bit on the fills
But there are probably plenty of SB people that could do a 6 hour macro dive at the BHB if they got familiar with the area...and if they really wanted to

 

[Kimela]

As they say, "the devil is in the details", and you managed to finally pull them all together for a comprehensive view of what happened. SO glad there was no DCS hit and you found out something very helpful for her overall health and comfort. I'm not GUE trained (couldn't tell you what it stands for even though I've read it repeatedly here) but I know I tend to dive so that my neck is hyperextended to try to stay as horizontal as possible. I'll be rethinking how that happens. My husband has stenosis in his neck and he complains about pain during and after diving. I'll discuss this with him as well. Thanks so much for sharing your experience.

 

[Pebbles Photo]

The chronic version of surfer's myelopathy is surfer's neck. One is a pinch and a kink of arterial flow, the other is chronic tightness and shortening of posterior neck muscles, leading to bone spur formation that can pinching of the spinal cord. Maybe we should come up with scuba neck, from being too trim of a diver.

What is Surfer's Neck?

Wow!!! What a great article on this "Surfer's Neck" link. Dan should speak with some of his GUE friends about doing an article on "surfer's neck" as it relates to diving for GUE people. Paddling a surfboard or frog kicking GUE style on an ocean dive, has so much in common at the area of your neck that this needs to become widely known by divers. It makes sense, given that surfing is a sport of so many millions of people, that the medical issues that go along with the sport - like this "surfer's neck", would be well documented and well dealt with by experts. Given GUE'ers are a population group so small as to not even being statistically relevant, if we don't develop this concept ourselves, there is almost no chance the medical community ever will!. I just mentioned this to Dan, and he is already thinking about a letter to Dr Daniel Grobman about this...for the GUE community and those that use the pieces of GUE that makes sense to them..the DIRish aspects It could be a great article for scubaboard.

Too bad that Scubaboard won't let Dan post here himself... Apparently he hurt some feelings of SB moderators years ago, and they won't drop the animosity they have for him...even though Dan is much "kinder and gentler" now
Maybe some of you guys could write in and request the change...this could be a "test topic" the moderators could gauge Dan Volker's better attitude and suitability to SB rules with

 

[Divin'Papaw]

Fascinating read. Thank you for sharing!