Odd question...

[Misfit]

I was reading one of my training books the other day, and it mentioned WBV (whole body vibration). It gave the impression that this causes a wide range of serious spinal issues, such as degenerative disc disease, bulging discs, and minute spinal fractures, just to name a few (cringe). I was unclear from the text whether this is an unavoidable consequence of flying helicopters in general, or just repeatedly flying one with balance issues, etc. I had never heard mention of this until I read this book.

 

I was wondering if anyone could give some real-world insight into this. Have any of you experienced these types of issues? If so, was there a specific cause, such as an accident or prolonged excessive (abnormal) vibration, or do you believe it is just something that goes with the territory of flying helicopters? And if that is the case, how long did it take for the problem to develop?

 

I have to admit, this did give me some pause when I read it - I have always been rather squeamish about spinal/nerve problems.

[slick1537]

I read it can also mess up your reproductive system if you are planning to have kids in the future.

[PhotoFlyer]

Never heard that before, but I suppose it could be true. I have had back problems for a long time now, and flying for extended periods doesn't help, but I don't feel any different than if I had driven for a long time.

 

Not only does it mess up your reproductive system, it will give you AIDS as well.

[kodoz]

WBV (whole body vibration)...causes a wide range of serious spinal issues, such as degenerative disc disease, bulging discs, and minute spinal fractures, just to name a few (cringe).

 

No personal experience, but looking in the medical literature database there are some reports of low back pain being more prevalent in helicopter pilots than in other professions. Vibroacoustic disease is another thing that pops up in aviation workers (50% in 4 years for minor symptoms, back pain and more severe symptoms in 4-10 years). And low frequency vibrations have been associated with some specific types of mutations that can lead to malignancies later in life (no mention of 2-headed mutant babies tho).

 

 

I was unclear from the text whether this is an unavoidable consequence of flying helicopters in general....

 

Sounds like it comes with the territory.

 

 

I have to admit, this did give me some pause when I read it - I have always been rather squeamish about spinal/nerve problems.

 

After years of reading studies like this, I've just accepted that living in general is pretty bad for you. It's not a matter of whether what you're doing is killing you, but how what you're doing is killing you. Figure that 50-75% of the population complains of low back pain at some point in life, and cancer is the second most common cause of death in the US.

[Darren Hughes]

From what I've read in different books not much is known about Whole Body Vibration as there haven't been that many conclusive studies. However from them sources I've figured out that WBV is definetly not good for you!! The FAA doesn't barely touch on it in any of their publications that I've read so far, I think there was one or two lines about it in one of their books. The most I've seen writen about it so far has been in a Caledonian Advanced Pilot Training(CAPT) book - JAA ATPL(H) Module 1. This comes from the "Human Performances & Limitations" Chapter, it was written by Phil Croucher who has writen a lot of different books on both fixed wing and helicopters;

"Whole Body Vibration

WBV can be experienced in two ways; through an instantaneous shock with a high peak level (enough to jar you out of your seat, as with turbulence) or through repeated exposure to low levels of vibration from regular motion, as with a helicopter with one blade out of alignment. Its relevance here is its contribution to fatigue(low-frequency vibrations of moderate intensity can induce sleep), but the most common effect of BV is lower back pain and inflamation that can lead to degeneration of discs or trapped nerves. However, of particular importance to long-liners, is the increase in its effects from twisted sitting postures, which increased stress and load on the neck, shoulder and lower back (the main purpose of lumbar support is to produce an even pressure on the discs by allowing the lower spine to curve naturally). For example, vibrations between 2.5 and 5 Hz generate strong resonance in the vertebrae of the neck and lumbar region. Helicopter vibration has a peak power at frequencies around 5 Hz. Vibration from engines can cause micro fractures in the vertebrae, disc protrusion, nerve damage and acute lower back pain. Otherwise, short term exposure has only small effects, such as slight hyperventalation and increased heart rate, plus increased muscle tension from voluntary and involuntary contraction(tenseness dampens the vibration).

 

Acute effects(short term exposures) include headache, chest and abdominal pain, nausea and loss of balance. Chronic effects(long-term exposures) include degenerative spinal changes, lumbar scoliosis, disc disease, degenerative disorders of the spine and herniated discs."

 

We're required to know this stuff for one of the JAA ATPL(H) exams.

 

After years of reading studies like this, I've just accepted that living in general is pretty bad for you.

 

I have to agree there, and there's not much point in dwelling on it too much. But I guess it's important to realize when getting into this business that you're more than likely in for a life of visits to the chiropractor.

 

On the plus side though, you can't beat the view from the office!!!

[Sugatrix]

IIII've seeeeeeennn nnnoo adddvvverssse aaaaaafffeccccts!!!!!!

[Gomer Pylot]

One of the consequences seems to be hemorrhoids. That is a very common complaint of older helicopter pilots, IME. You see them having surgery for them all the time. Maybe I've just flown smooth ships over the years... Nah, I know better than that. Probably I'm just lucky. Some people smoke 2 packs of cigarettes a day their whole lives, and never get lung cancer. I've never had serious hemorrhoid problems. At least, not serious, not yet.

[Misfit]

Darren:

That is exactly the book I was talking about - "Professional Helicopter Pilot Studies" by Phil Croucher! That passage is the one that made me concerned about this! It really makes it sound serious.

 

"...through repeated exposure to low levels of vibration from regular motion, as with a helicopter with one blade out of alignment..."

 

That was the part that confused me - obviously there is vibration in every helicopter, but is it enough to cause these problems, or does there have to be a specific issue (such as a blade out of alignment) to cause this sort of "damaging" vibration?

 

This is the line that really freaked me out -

 

"...Vibration from engines can cause micro fractures in the vertebrae, disc protrusion, nerve damage and acute lower back pain..."

 

I'm wondering about PERSONAL experience from long term helicopter pilots - have you noticed any back problems? What kind? How long have you been flying? I'm just trying to get an idea if this is really as serious and/or widespread as Croucher makes it sound.

 

kodoz: "...(50% in 4 years for minor symptoms, back pain and more severe symptoms in 4-10 years)..."

 

Does this mean that I will start having severe problems from this after only 4 years of flying? Somehow the idea of needing back surgery at 35 doesn't really appeal to me. Is there any way to avoid these problems? Exercises, etc?

 

Like I said, I am much more interested in personal experiences than I am literature on the subject. What they say in books rarely corresponds to the real world, for better or worse.

 

Thanks to everyone who replied!

[kodoz]

kodoz: "...(50% in 4 years for minor symptoms, back pain and more severe symptoms in 4-10 years)..."

 

Does this mean that I will start having severe problems from this after only 4 years of flying?

 

That 50% was an average from a group of ~150 people that were studied, and the timeframes were the ranges they observed for those symptoms appearing. If this was a bigger study and better researched (like say the Framingham Heart Study, which is the source for a good chunk of our knowledge about who is at risk for cardiovascular disease), I'd say yeah, fly helicopters for 8 hours a day and you have a 50% chance of minor back pain developing in 4 years. In this case, it's not that the literature doesn't correspond to reality but that there's not enough research to pin down your actual risks. And, ascribing a reason for something like back pain is difficult since so many people develop it for many different reasons (like sitting all day), it's difficult to conduct the proper research to say helicopter pilots develop it because of WBV.

 

There may be some specific exercises that might help in this article but, in this case, I'd say do healthy things, eat foods that are good for you, exercise (aerobic, weight-bearing, and flexibility), don't get fat, and if you smoke, quit doing that. Those are all things that will improve your general health and will mitigate your risks for spinal degenerative diseases and other nasties.

 

Like I said, I am much more interested in personal experiences than I am literature on the subject. What they say in books rarely corresponds to the real world, for better or worse.

 

Aww, comon. Books are our friends! Like our POH and the Rotorcraft Flying Manual. Definitely better sources of info than anything you're going to read on the internet!

[Gomer Pylot]

I don't think the cause of the back problems is the vibration as much as the seats. Out of something over 13,000 hours in helicopter seats, I've never spent a second in a comfortable one. They're ok for a half hour or so, maybe even up to an hour. But spend 8 hours a day, every day, in one and you'll be in constant pain. Engineers design a helicopter, have it all just about ready to go, and realize that they need a place for the pilot to sit. So they throw something together in 5 minutes. There is no lumbar support, no thigh support, no ergonomic considerations at all. I've literally seen people get out of helicopters and be unable to walk for awhile. At the least, you generally have to stagger around for awhile before you can walk normally. Using a lumbar cushion and a Relax-o-bak seat helps some, but it's still torture, and there is no other way to describe it. It matters not if the helicopter is brand new or many decades old - the pilot's seat will cause you intense back and buttock pain if you spend more than an hour or so in it at a time, and especially if you spend 6 or 8 hours a day in one. I used to spend up to 14 hours a day in a 206, logging less than 8 hours flight time, and it was excruciatingly painful. But that's the life of a helicopter pilot. It's what everyone longs to do. In the end, pun intended, everyone will pay.

[tiercel]

One of the consequences seems to be hemorrhoids. That is a very common complaint of older helicopter pilots, IME. You see them having surgery for them all the time.

Hemorrhoids are more likely caused by holding "it" in too long, then forcing "it" out with lots of force. This causes blood to collect in blood vessels around the rear exhaust, which causes the blood vessels to swell and stretch, causing varicosities. I think pregnancy can do the same thing. Pickle your load regularly and don't push like your giving birth to a 2nd Lt., just relax and let it happen.

[Darren Hughes]

Jesus, this topic has taken a turn for the worse!!

[PhotoFlyer]

Hemorrhoids are more likely caused by holding "it" in too long, then forcing "it" out with lots of force. This causes blood to collect in blood vessels around the rear exhaust, which causes the blood vessels to swell and stretch, causing varicosities. I think pregnancy can do the same thing. Pickle your load regularly and don't push like your giving birth to a 2nd Lt., just relax and let it happen.

 

Good lord, that was WAY too much information. Or perhaps it was the way it was worded. I don't know, but that really struck me as wrong.

[FredR]

Hemorrhoids are more likely caused by holding "it" in too long, then forcing "it" out with lots of force. This causes blood to collect in blood vessels around the rear exhaust, which causes the blood vessels to swell and stretch, causing varicosities. I think pregnancy can do the same thing. Pickle your load regularly and don't push like your giving birth to a 2nd Lt., just relax and let it happen.

 

I'm sorry, maybe it's the night shift but I thought this quote was hilarious. Definitely TMI....the 2LT comment was an interesting touch.

[Misfit]

Aww, comon. Books are our friends! Like our POH and the Rotorcraft Flying Manual. Definitely better sources of info than anything you're going to read on the internet!

 

I certainly didn't mean to imply that books are not great sources of information, or that the internet was better. I was just saying that you can find a book or article to support almost anything you could think of, and in this case, rather than a study saying "Such-and-such percent of pilots report back pain" (of course they do - as someone said, everyone has back pain - that doesn't tell me anything), I wanted to hear from you guys (actual high-time pilots): Do you have back pain you believe is from flying? Are you only uncomfortable while you're in the pilot's seat, but fine once you get out? Or do you have problems sleeping, walking, or other activities because of it? Have you been diagnosed with specific issues, such as DDD or herniated discs? Have you needed to take medication, or have surgery, because of it?

 

I'm just trying to get an idea of how all those scientific studies translate into the real world. I very much want to fly, and I have no problem accepting the RISKS associated with it, but the idea that (as Gomer said) I WILL be in excruciating pain while I do it (and possibly the rest of the time as well) kind of takes the fun out of it. There's a big difference between something that "might" happen, and something that just "comes with the territory". There is also a big difference between occasional discomfort and constant pain and/or irreversible spinal damage. Before I continue on this path (or make the decision not to), I want to be sure I have the facts straight.

 

I really appreciate everyone's advice and information. Sorry to ask so many questions, but this is very important to me. I don't want to change my whole career path based on something that is not that much of an issue, but on the other hand, I don't want to get four years into it and find out I can't even walk without pain anymore.

[FredR]

Misfit,

I would agree with Gomer. I started flying helicopters in 1991 and have not found one in which my butt could last more than two hours before I decided I wanted to be somewhere else. Most of my experience has been in military aircraft, but even in the newer designs, the seats might as well be a milk crate. Ditto for the civilian aircraft that I've been in so far (the 206 has had the most comfortable seat for me so far...go figure). I've been in that situation where I could hardly walk after flying but it was after 3+ hours straight of long lining and I've found myself to get a little tense during that activity. I think that stress / tension and the poor design (ergonomics) of the aircraft compound the problem. I would think that regular exercise and spending some time between flights outside the aircraft (if possible), helps to alleviate the problem. I have no knowledge on the WBV issue, just what I've experienced.

Fred

[Gomer Pylot]

The anecdotal stories you'll get here are far less useful than scientific studies which examine large numbers of cases. I have back pain only during and soon after flying, but I'm certainly not everyone, and probably not representative of pilots in general. One case, or even several, means nothing. You need a large number of cases before you can even begin to draw any inferences about probabilities, and probabilities are the best you can get. Your case is specific, and has little to do with any other individual case. If you can find data on many individuals, then you can begin to calculate the odds of your having similar outcomes. It's only odds, though, and never certainty.

[Cruzin Chris]

I’ve only done two jobs full time in my life. Fly helicopters and beach patrol lifeguard. While I have experienced hearing loss from 18 years of flying… lifeguarding has given me a hernia that needed an operation, a torn rotator cuff and lots of skin problems. Flying a helicopter is much easier on my body!

[Gomer Pylot]

Chris, what's the story with the snow baffles and clear sunny skies?

[Misfit]

The anecdotal stories you'll get here are far less useful than scientific studies which examine large numbers of cases. I have back pain only during and soon after flying, but I'm certainly not everyone, and probably not representative of pilots in general. One case, or even several, means nothing. You need a large number of cases before you can even begin to draw any inferences about probabilities, and probabilities are the best you can get. Your case is specific, and has little to do with any other individual case. If you can find data on many individuals, then you can begin to calculate the odds of your having similar outcomes. It's only odds, though, and never certainty.

 

The problem with studies or surveys is that they are very broad and general. If you give a pilot a survey that says, "Do you have back pain?" what do you expect them to say? Of course they will say yes. I think if you asked that question of people on the street, you would get a bunch that said yes.

 

What I'm trying to get (besides something to make me feel better about this!) is specifics. That's why I posed the question here - to get a real person's description of what kind of pain, how does it affect their life, is it just "uncomfortable" to fly, or have they had serious issues because of it. These are the facts that will decide whether or not this is a sacrifice I am willing to make for this career, or if I will have to just settle for my PPL. In other words, I am willing to accept the fact that I will be uncomfortable while I am flying, and for a short time afterwards. I am not willing to accept the fact that I will have DDD, and possibly need surgery for it, after only four or five years of flying. So I am trying to figure out which of those is closer to the truth. I can't seem to find that information in a study.

 

FredR and Cruzin Chris: Thank you, those descriptions put it into terms I can relate to!

[Gomer Pylot]

Just because one person has pain, or has none, that doesn't mean you will, or won't. Scientific studies will give you the most accurate probabilities, but it's still just a probability. They don't just ask random people random questions, that isn't how science works. But in the end, it's your decision, so make it based on whatever you like - the phase of the moon, tea leaves, or what someone here says.

[Darren Hughes]

Misfit, you got mail. Just PM'd you.

[Ross85]

I definitely think the helicopter seats have a lot to do with some back problems. You are sitting in an uncomfortable seat for hours and not stretching at all. When you are concentrating on flying so much, you don't notice how uncomfortable you are until you get up. I would say the pain is more from not moving and having poor seats with little lower back support than vibrations.

[SquirrelFlight]

I brought this up to the chiropractor I've been going to (I get 1 hour massages billed to the insurance company as part of "physical therapy"), and he was kind of puzzeled at the idea of vibration causing medical problems. He mentioned that some of the newer therapy techniques make use of whole body vibration.

 

I just rescanned the thread, and maybe I just missed it, but was there an actual medical reference to the WBV problems or the virboraccoustic diseases someone brought up? He said he'd look into it if I could find somewhere for him to start...

[kodoz]

I brought this up to the chiropractor I've been going to (I get 1 hour massages billed to the insurance company as part of "physical therapy"), and he was kind of puzzeled at the idea of vibration causing medical problems. He mentioned that some of the newer therapy techniques make use of whole body vibration.

 

I just rescanned the thread, and maybe I just missed it, but was there an actual medical reference to the WBV problems or the virboraccoustic diseases someone brought up? He said he'd look into it if I could find somewhere for him to start...

 

Yes, there were...but I don't have them handy anymore. If you're familiar with PubMed, search for "whole body vibration" and/or "vibroacoustic disease" (VAD seemed to be more frequently associated with pathological conditions, WBV sometimes with therapeutic approaches); you can limit the searches by adding "helicopter" or "aviation" to the search terms. There are some studies about short term treatments benefiting patients with, for example, Parkinsons disease and cystic fibrosis. Then there are also occupational studies looking at subjects who are exposed to WBV for long periods. PM me if you have any trouble finding what you're looking for.