Bad Knees

[MacLir]

I have some problems with me knees stemming from prior injury (non-diving related) as well as psoriatric arthritis. The knees don't trouble me generally when diving, but getting back on the boat can be a bit of a challenge. My (non-diving) rheumatologist has suggested neopreone knee braces to help stabilize the knees to take the equipment weight when coming up the ladder. I was concerned that the braces might cause constriction and increase the risk of a DCS hit. My instinct is that the braces should not present any more risk that the wetsuit does and that the same guidelines should apply (i.e. don't have them crazy tight). But, I don't know if that is right. Does anyone have any thoughts on the wisdom of using knee braces when diving and/or experience using them in that context?

Thanks in advance!

 

[Akimbo]

On knee braces, no. On decompression, yes. I have known at least half a dozen divers who would frequently get knee pains diagnosed as the bends. Fortunately we had chambers on site to treat them. All of them had previous knee injuries. I suggest being extra conservative regarding decompression dives. Maybe even consider using O2 instead of air at decompression and safety stops for an added safety margin.

 

[helimvee]

Have you tried calling DAN?

Akimbo ... do you know what kind of knee injuries these divers had and/or whether the ever got an explanation? I have had issues with my knee and am very curious about this.

 

[Akimbo]

Have you tried calling DAN?

Akimbo ... do you know what kind of knee injuries these divers had and/or whether the ever got an explanation? I have had issues with my knee and am very curious about this.

High school football on one, bad decompression chamber posture on two, and a broken leg as a kid on the third. No idea on the other 3-4. This may explain more:

Perhaps a more precise way of asking it would be: Is it possible to exhibit symptoms of Decompression Sickness (DCS) in one joint?

In my experience treating other divers the answer is absolutely yes. Most often, hyperbaric physicians postulate that it is likely from a previous joint trauma — either from a physical injury or a previous detected or undetected DCS incident. The theory being that circulation was compromised by previous injuries.

One of the best diving supervisors, and retired Navy Master Diver, I ever knew would get hit and ride Table 4 almost every time he got wet. It was always the same knee.

An especially large commercial diver had a habit of sitting on one folded knee in the chamber during Sur-D-O2 runs (Surface Decompression using Oxygen). The supervisor would tell him repeatedly to straighten his legs but he kept on. Sure enough, he began to frequently take a hit in his knee even after changing his practice. He is not diving anymore.
...

Knees are the most common hits I have seen by a wide margin. Reduced circulation due to folded limbs is the reason the Navy stopped decompression during sleeping hours in the early 1970s. I am not sure they still do, but several companies do for the final 2-3 days.

We had several hyperbaric docs trained at the old Washington DC EDU around when I was in the Navy, but they were very rare offshore. The scar-tissue/reduced circulation theory seamed very logical, but I can’t say what the latest best guess is. The more you study this stuff the more you realize how little is known and how many human variables there are.

The good news is you will "probably" get hit in the knee before the CNS. All your buddies can use you for "the parakeet in the mine". You probably don't want to push it too far if you are more than a half hour chopper ride to a chamber though.