Non-technical dive-planning software?

[jeckyll]

The study I read a few years ago showed a 20 or 30% reduction in bubbles for subject who exercised 24 - 4 hours before a dive by running a few miles (not too much). Sorry, I have no time to search for it now.

Moving after diving is good as is keeping circulation going, but not exercising (just like hot showers, too much circulation is not the right thing).

 

[eponym]

What I am still confused about is how the very slight exertion of climbing out of the water would promote shunting over.

Shunting aside, exertion can lead to growth of bubbles from bubble seeds in the joints.

As the caps (ends) of two long bones flex hinge-like, or as one cap rotates in a socket, there are minute areas which momentarily* experience much lower pressure than the surrounding tissue. These low-pressure transients can allow microbubbles to expand to a size that triggers the inflammatory response that is thought to be part of the chain of events leading to DCS pain. This explains why joint pain is a common symptom.

The principle involved is "tribonucleation" which is also what causes cavitation on ship's screws when they're turned too fast. And it explains why strenuous exercise after diving is generally discouraged.

I figured the exercise, when I do it, would help with off-gassing and be a good thing all around.

Compared to just sitting, some light exertion (walking, for instance) can increase blood flow throughout your tissues. Increased blood flow (perfusion) is good because it speeds up transfer of dissolved nitrogen from tissues to the lungs, where it's offgassed.

-Bryan

* using the word in its traditional sense of "for just a moment" rather than the airlines' sense of "very soon."

 

[daniel1948]

Wow. Thanks for all that, especially for the link to the DAN item. I'll remember that.

 

[Kevrumbo]

Shunting aside, exertion can lead to growth of bubbles from bubble seeds in the joints.

As the caps (ends) of two long bones flex hinge-like, or as one cap rotates in a socket, there are minute areas which momentarily* experience much lower pressure than the surrounding tissue. These low-pressure transients can allow microbubbles to expand to a size that triggers the inflammatory response that is thought to be part of the chain of events leading to DCS pain. This explains why joint pain is a common symptom.

The principle involved is "tribonucleation" which is also what causes cavitation on ship's screws when they're turned too fast. And it explains why strenuous exercise after diving is generally discouraged.

Compared to just sitting, some light exertion (walking, for instance) can increase blood flow throughout your tissues. Increased blood flow (perfusion) is good because it speeds up transfer of dissolved nitrogen from tissues to the lungs, where it's offgassed.

-Bryan

* using the word in its traditional sense of "for just a moment" rather than the airlines' sense of "very soon."

Yeah, I've been a victim of that:
http://www.scubaboard.com/forums/near-misses-lessons-learned/264517-type-i-bends-hit-chuuk.html
Also, this article is a good description of how the immune system and the inflammatory response may play a part in DCS as well:
Rethinking the Hit

 

[boulderjohn]

Also, this article is a good description of how the immune system and the inflammatory response may play a part in DCS as well:
Rethinking the Hit

Very interesting. I am afraid tht I skimmed the parts that were outside the realm of my knowledge base in search for the practical tidbits, the "so what does this mean for me?" stuff. I think I pulled what I need from it, but I would love to see a summation for the lay diver.

What I pulled from it is very thought provoking in terms of some of some recent experiences, especially the part near the end about repetitive diving.

Has there been discussion of this in other forums that I could peruse?

 

[lowviz]

Very interesting.

Yes, Kevrumbo, nice find. I've taken two courses with her, most worthwhile. -missed that article.

Boulderjohn, being an instructor you might be able to get enough students together to have her ( Team Lifeguard Systems - Public Safety Diving Training Equipment other Water Operations Rescue/Recovery ) drop by and teach their famous recreational diver course. Questions are free, very unlikely that you would be disappointed. Apologies to Daniel for my being a bit off-topic.

 

[boulderjohn]

Also, this article is a good description of how the immune system and the inflammatory response may play a part in DCS as well:
Rethinking the Hit

Before we get too excited, check here to see where I asked for responses to this article:
http://www.scubaboard.com/forums/ask-dr-decompression/279200-dcs-immune-system.html