Caver Anatomy
- Thread starter Amy
- Start date
simonsays
New member
So, an update...
Popped down calf holes this afternoon with my modified harness (Its a short, simple pitch Amy. Maybe 35'?)
Big difference in the perceived security of my in-harness position. It felt much better as my centre of gravity was below my attachment point on the rope. I was happy to lock off and take both hands of the descender to fiddle with my camera. No hint of falling back.
I didn't have the opportunity to try ascending as it was a through trip and we had two 13 year olds with us who needed minding down the abseil (they both did really well).
Thanks for everyone's input.
Popped down calf holes this afternoon with my modified harness (Its a short, simple pitch Amy. Maybe 35'?)
Big difference in the perceived security of my in-harness position. It felt much better as my centre of gravity was below my attachment point on the rope. I was happy to lock off and take both hands of the descender to fiddle with my camera. No hint of falling back.
I didn't have the opportunity to try ascending as it was a through trip and we had two 13 year olds with us who needed minding down the abseil (they both did really well).
Thanks for everyone's input.
RobinGriffiths
Well-known member
There could be a gap in the market for Potholer's Wives Magazine.
Roger W
Well-known member
Clearly Robin thinks he has enough to support the circulation of a specialist magazine! :bow:
But let's not allow this stuff to distract us from Amy's original subject. Keeping close to the ladder or rope is evidently a problem for quite a few of us - I can remember a time when there was a lot less of me round the middle than there is now! - and the bits of the thread on those lines was quite informative.
Incidentally, has anyone ever done a survey on cavers' physiques? How does the average UK caver's BMI, for example, compare with that of the average Bangladeshi or Barbadian?
But let's not allow this stuff to distract us from Amy's original subject. Keeping close to the ladder or rope is evidently a problem for quite a few of us - I can remember a time when there was a lot less of me round the middle than there is now! - and the bits of the thread on those lines was quite informative.
Incidentally, has anyone ever done a survey on cavers' physiques? How does the average UK caver's BMI, for example, compare with that of the average Bangladeshi or Barbadian?
BMI is largely inaccurate. It was developed using the typical caucasian male in his mid-30's. That's what the scale is based on. Anyone with decent muscle, or larger hips, or breasts, or curves, etc, throws the whole thing off. Ex: a typical athletic person who is perfectly healthy often falls on the scale of overweight or even obese. I doubt a survey of BMI would ever be useful because the numbers are so inaccurate. It makes no effort to distinguish bone from muscle from fat, bone and muscle are both denser than fat. You can have large bones, that's not a "hoax". A quick-and-dirty to determine if you really have large bones or just say so is take your thumb and middle finger and place it around your wrist of your other hand. Don't squeeze just place. If your thumb and middle finger overlap, you have skinny bones, if they meet, you have medium bones, if they dont' meet, you have thick bones.
BMI was actually developed about 200 years ago by a Belgian mathematician and has nothing to do with actual physique. In the formula, you square the height of the person. There's...no physiological logical reason to do this, it just made the formula fit the data and make a nice normal curve. Uhm, if you have to fake your equation to make the data look how you want it, you're doing it wrong....
Additionally it's a logic fail. I can calculate my BMI from my weight and height, which tells me what my BMI is. But actually, it was explicitly stated when developed that it should not be used to determine the "fatness" or fitness of an individual. So to say that a certain level of BMI = fatness, is pure hogwash. You can put in height and weight to get BMI, but you can't then take BMI to get fat-level, or fitness level.
A more accurate measure is waist circumference, because the amount of fat around your midsection is the "bad spot", physiologically, for fat to be at. Someone with toned abs doesn't affect this ratio, but someone with too much fat around the midsection does. Interesting example: myself - I am obese by BMI standards, but by adipose tissue measurements I am normal & healthy.
BMI was actually developed about 200 years ago by a Belgian mathematician and has nothing to do with actual physique. In the formula, you square the height of the person. There's...no physiological logical reason to do this, it just made the formula fit the data and make a nice normal curve. Uhm, if you have to fake your equation to make the data look how you want it, you're doing it wrong....
Additionally it's a logic fail. I can calculate my BMI from my weight and height, which tells me what my BMI is. But actually, it was explicitly stated when developed that it should not be used to determine the "fatness" or fitness of an individual. So to say that a certain level of BMI = fatness, is pure hogwash. You can put in height and weight to get BMI, but you can't then take BMI to get fat-level, or fitness level.
A more accurate measure is waist circumference, because the amount of fat around your midsection is the "bad spot", physiologically, for fat to be at. Someone with toned abs doesn't affect this ratio, but someone with too much fat around the midsection does. Interesting example: myself - I am obese by BMI standards, but by adipose tissue measurements I am normal & healthy.
cap n chris
Well-known member
Thin, short, fit = caving greatness
cap n chris
Well-known member
Nopeywopey
droid
Active member
I reckon it's not so much physique as weight that affects SRT comfort.
Years ago, I was a bat fastard: 5'6" and 185lb. I struggled on things like Bar Pot (120')
Now I'm 148lb and did a 200' pitch a while back, after a 10 year layoff, not easily, but a damn sight more comfortably.
......
Years ago, I was a bat fastard: 5'6" and 185lb. I struggled on things like Bar Pot (120')
Now I'm 148lb and did a 200' pitch a while back, after a 10 year layoff, not easily, but a damn sight more comfortably.
......
pwhole
Well-known member
I'm with Amy on BMI - it's medieval quackery held up as high science. There's no earthly reason why the formula should or could be applied to a human body - it's describing a slab of Spam?, effectively.
I was once described as 'obese' by a practice nurse, when anyone who knows me would counter that description immediately - I just have some muscles. But a 32" waist on a full-grown 5' 10" adult male cannot be obese in any sane world, and I caused a bit of an argument by dismissing the BMI theory so vehemently she asked me to leave. The scary bit was, she knew I was right, but only had the BMI formula to 'officially' use and so felt a bit adrift.
A shame, in the modern world, for the medical establishment to be so retarded on some really obvious issues. At least they don't use ducking-stools any more...
I was once described as 'obese' by a practice nurse, when anyone who knows me would counter that description immediately - I just have some muscles. But a 32" waist on a full-grown 5' 10" adult male cannot be obese in any sane world, and I caused a bit of an argument by dismissing the BMI theory so vehemently she asked me to leave. The scary bit was, she knew I was right, but only had the BMI formula to 'officially' use and so felt a bit adrift.
A shame, in the modern world, for the medical establishment to be so retarded on some really obvious issues. At least they don't use ducking-stools any more...
kay
Well-known member
pwhole said:
It's basically weight divided by height squared, in effect a weight to area ratio. I can see a sensible formula of, say, weight to volume ratio. But of course volume increases with weight, so that ratio might be effectively constant. Weight to height ratio seems more sensible, and it's what we use in normal conversation "Is she really only 8 and a half stone? Well, she's only 5ft 2. I'm 5ft 8 and I'd be really underweight if I were only 8 1/2 stone".
So where does the square come from? My guess is that someone measured weight and height of a lot of people and tried to relate the two, came up with some formula like "best estimate for weight is 1.372 stone + 21.84 height squared" and turned it into an "index" - weight / height squared "should be" about 22 point something.
This seems to be backed up by googling
"What is the scientific basis for the formula? We have to go back to Quatelet and read that "in 1846 he published a book on probability and social science that demonstrated as diverse a collection of human measurements as the heights of French conscripts and the chest circumferences of Scottish soldiers could be taken as approximately normally distributed." (sites 2 and 3 listed below). Therefore the most likely explanation is that both the BMI and the linear expression of Equ. (2) were derived as a gross approximation to a set of observed weights and heights of recruits in a Western European army. An additional tiny piece of evidence for such an origin is the fact that my own weight when I was conscripted into the Greek Army was that given by Eqs (1) or (2)."
http://www.theopavlidis.com/HealthIssues/bmi_0.htm
My 30 inch waist tells me I am overweight. But my BMI is 22. It works both ways.
The medical establishment is not known for its confident understanding of maths.
pwhole
Well-known member
Some excellent stuff there, Fulk. Ironically, my flippant comment about the use of a ducking stool would actually provide the best volume measurement of a human body, by capturing the displaced water in a measuring vessel.
Then we'd know for sure who's a fat lazy witch or an active, muscly witch
Then we'd know for sure who's a fat lazy witch or an active, muscly witch
blackshiver
Member
Just found Decent 29 with the results of the Miss Decent 1973 contest posted earlier in this thread!
Miss D was an Anne Sherratt Photographed by Rich Rose.
Miss F was a Carol Roberts (in Toyland!) - who had many admirers whom, according to the postmarks on the returns, lived on the Flyde Coast! Photo taken by Neil Horesfield.
Paul (Deakin) cheated a bit by entering two photographs. Miss E was his wife - who lost out to Miss A (I shall copy this picture tomorrow evening and post it on my Blackshiver Flicker page). This must have been an interesting day out in Carlswark studing caver anatomy then Paul.....
Miss D was an Anne Sherratt Photographed by Rich Rose.
Miss F was a Carol Roberts (in Toyland!) - who had many admirers whom, according to the postmarks on the returns, lived on the Flyde Coast! Photo taken by Neil Horesfield.
Paul (Deakin) cheated a bit by entering two photographs. Miss E was his wife - who lost out to Miss A (I shall copy this picture tomorrow evening and post it on my Blackshiver Flicker page). This must have been an interesting day out in Carlswark studing caver anatomy then Paul.....
blackshiver
Member
Credit for Paul Deakin for this one (decent 1974) - an interesting insight to caver anatomy and the equipment of the 1970's.
If the photo does not appear its on my blackshiver flickr page and judging by the 700 odd views of the Miss Decent 1973 one there are a lot more cavers out there than I thought.
Bother; Bograt, your brandy medicated instructions don't work........
If the photo does not appear its on my blackshiver flickr page and judging by the 700 odd views of the Miss Decent 1973 one there are a lot more cavers out there than I thought.
Bother; Bograt, your brandy medicated instructions don't work........
