Wrist measurements and body frame size

[Steph2825]

So im curious to know if anyone has looked into bone structures and body frame size.

I found this interesting chart that says to measure your wrist size to determine your body frame size.

Now my wrists arent fat and even if i squeeze a tape measure around my wrist i cant seem to get less than a 6.5 inch measurement and im 5'6 tall.

I have to laugh at the thought of being genuinely big boned. I talked to my dad about it and he said my mom is big boned.

Thoughts?

 

[Trusylver]

There is not very good science behind this, there is a small amount of correlation but not much real science. We did do wrist measurements at uni as part of studies on gathering anthropomorphic data to assess athletes. this is one study Prediction and measurement of frame size in young adult males - PubMed

It is certainly not an excuse to carry excess fat.

I personally have a large bone structure. I know this from my surgeon who has seen and worked on my bones and my bone density is large due to doing heavy weight bearing exercise over my lifetime.

however here is a formula for the men, this is the calculation for maximum lean mass a natural athlete can build based on a mix of wrist and ankle circumference modified by bodyfat%

There is no formula for females as the subjects were all men in developing this formula over



H = Height in inches
A = Ankle circumference at the smallest point
W = Wrist circumference measured on the hand side of the styloid process.
(The styloid process is the bony lump on the outside of your wrist.)
%bf = The body fat percentage at which you want to predict your maximum lean body mass

One must also consider the case where a person's bone structure tapers at the extremities. For instance, the wrist and ankle circumferences could be "small" but the shoulder and hip structures not correspondingly "small". This trait is not entirely uncommon and can produce deceiving results. The opposite end of the spectrum is a slightly built person who has large wrists and ankles - this type of structure also exists. In these cases, it is more difficult to accurately predict muscular potential. I have chosen to present a simplified lean body mass prediction equation, but with the caveat that an adjustment be made for thinly and thickly built men whose structures are not accurately reflected in their wrist and ankle measurements.

 

[Steph2825]

That was an interesting read. Too bad we probably wont see an in depth study done on something like this, at least not in the near future, i imagine.

 

[Llama]

I have wide wrists, ankles, hips, and shoulders but my neck is almost comically thin. It's going to be hard to figure out a useful formula given the enormous variety in human form. Which may be why more research doesn't go into it.

 

[alligatorob]

I can tell you that as I have lost weight (and circumference) everywhere. My wrists have become smaller, and I thought I had nothing to lose there. Ankles too, everything pretty much is smaller now. Apparently my "big" bones that I had assumed all of my life were there turned out not to be bone alone.

 

[Llama]

Standard bracelets wouldn't close around my wrists even when I had a bmi of 19 (at 20).

 

[Err2]

I can tell you that as I have lost weight (and circumference) everywhere. My wrists have become smaller, and I thought I had nothing to lose there. Ankles too, everything pretty much is smaller now. Apparently my "big" bones that I had assumed all of my life were there turned out not to be bone alone.

When I first got a fitbit in May I only had about 1/3 of the holes remaining on the largest band. Now I'm 4 holes into the small/medium band...

View attachment 38539

H = Height in inches
A = Ankle circumference at the smallest point
W = Wrist circumference measured on the hand side of the styloid process.
(The styloid process is the bony lump on the outside of your wrist.)
%bf = The body fat percentage at which you want to predict your maximum lean body mass

In this equation is 36.9% BF expressed as 0.369 or as 36.9? I get either 167 lbs max lean mass or 194 lbs max depending on how I input the percentage...

(67 inches, 7.5" wrist, 9.75" ankle, 36.9% BF). Either way I am a little skeptical - I conservatively estimate I had over 200 lbs lean mass when I weighed 450 lb and I had 162.5 lbs lean mass on my dexa scan a few weeks ago (that 162 did not include ~8 lb of bone mineral).

 

[Err2]

^ It must be entered as 36.9 because if I enter 50% BF as 50 using the same measurements I get 204lb max lean mass which is closer to the ballpark (unfortunately I did not take full body measurements when I started)