Footprint measurement experiment - help needed! Options

[Paul1968UK]

I was on the beach yesterday, taking a nice day off with the kids. I was looking at the prints my enormous size 15 feet left behind, and remembering what someone once said about a plaster cast being a representation of what a a foot does to the ground when it strikes it rather than being an imprint of a foot, and then thinking about the recent discussion about Patty's foot measurement being unreliable, it got me thinking.

On BFF and plenty of other forums, we have at out disposal hundreds of people who could contribute to an effort to measure their footprints. I know when I looked at my footprints in damp sand yesterday, the prints were approximately 2cm longer than my feet.

What we woudl need to do is to take a series of measurements - say, length and breadth of foot, weight of subject, type of soil/sand, length and breadth of print.

Where possible, make plaster casts and measure them.


If we collected enough data from people, we could could then calculate what the average enlargement of a print/cast is compared to the actual foot and compare them to known casts such as Patty's.

I would recommend everyone measures say five of their own prints.

I'll take advice from someone as to what consitutes 'breadth' as far as human feet are concerned.


How about it?

[Volsquatch]

I'd recommend at least two sets of cast be made of impressions in a sand substrate - one set in damp sand and one in dry.

When sand is soaked wet, impressions will automatically go deeper. When the sand dries it becomes much firmer and the impressions won't penetrate as deep.

I'm still convinced that something to this effect was going on with the "Patty" tracks in '67.

[Night Stalker]

Supposing that you gather enough data to satisfy our resident rocket scientists to debate 10 pages, and determine that the variance is on average a 1% increase for every 2" of actual foot length, what would that information actually do for you?

Should we subtract 1\2" from all supposed BF tracks? Can we be certain that this principle applies to their tracks as well? Does anyone here weigh several hundred pounds? Is this information as empirical as the age of the track?

Just asking . . .



.

[Volsquatch]

Should we subtract 1\2" from all supposed BF tracks?

Of course the results of this experiment will not cause all "supposed BF tracks" to have 1/2" subtracted from them, that's a hasty generalization. One must take into account the varying compositions of the substrates in which the impressions were made.

[Paul1968UK]

Thats precisly the information I would like us to ascertain - what the difference between soil types is. I've heard a lot of anecdotal evidence about different types of soil, but we should be able to do better than that.

[Searcher67]

Well,



|---horizon cut--------------|
-------------\ /--------------------
\ /walls
| Floor |
-----------------------------------------------------------------
Lateral ridge (actual track)

The horizon cut is where and how the track maker placed and removed its foot

Then you have pitch and straddle

Well, the reply doesn't look right after I hit the send button/ but it looks fine right now


The pitch is how the feet turn out
the straddle is the measurement where the heels are apart

stride length is measured from heel to heel

Then you have compression shapes: these may be circles, ovals or rectangles

The reply doesn't look right after I hit the send...So the horizon cut is where the foot enters and leaves the ground

the walls are the edges and the floor is the bottom or the actual track itself

This post has been edited by Searcher67: May 25 2009, 04:52 PM

[Night Stalker]

Of course the results of this experiment will not cause all "supposed BF tracks" to have 1/2" subtracted from them, that's a hasty generalization. One must take into account the varying compositions of the substrates in which the impressions were made.

Of course it's a hasty generalization, what else could it be? I think it is so obvious it wasn't worth commenting on. Accounting for varying compositions in substrates is also a given, that wasn't what I was asking Paul1968UK. It doesn't take a team to know that softer ground and wetter soil or a heavier mammal could leave deeper footprints, I think Paul's children already know that without explanation.

When he gets all this data, half of which will be rejected because it doesn't meet our resident experts criteria, what will the result be? Does the sand to soil ratio make a difference? Probably. Does the temperature make a difference? Probably. Is this due to surface shrinkage in the drying process? probably. How wet is wet? How dry is dry? Dry hard compact or dry soft soft soil? What is the minimum weight requirements in order to be a candidate?

In the end, what will the analysis tell? "A: prints left in wet soil or sand will be larger or become larger, where as B: prints left in dry sand will not be as deep, but will not be increased by the casting process and or found to be a closer match".

And if this is exactly what the point is, then should we have a tighter control than just randomly stepping with bare feet?

I saw some guys try a similar test on MonsterQuest, but imho they screwed it up. They built a frame and attempted to leave tracks with 2 feet at once, and not a single step.

I'm just asking for Paul to more clearly identify what he wants from the end result in order to define the exact steps required to accomplish this.


.

This post has been edited by Night Stalker: May 25 2009, 04:59 PM

[StacyInMI]

I did this about 3 years ago Paul, but then never really did anything with it. I measured the length, ball width, and heel width both weight bearing and non-weight bearing, then made casts in some nice squishy mud. It'll take some time to find the measurements but I'll try to get that up for you Wednesday.

One problem I had though, is that I measured the length of my foot on top of a ruler with my heel against the wall...that was wrong for what I was doing, since the back of the heel that projects out isn't part of the track/print/cast. If we measure a wet footprint on the cement, that wouldn't really be accurate either if the foot sinks more than a millimeter or two into the substrate. So, can anyone suggest what might be the most accurate way to take a foot measurement that would most likely correspond to the part that would actually make the imprint?

Hope that makes sense. I've been 3 nights in a tent and am slightly sleep-deprived.

stride length is measured from heel to heel

Of the same foot (ie. right heel to right heel, or complete two steps). From the heel of one foot to the heel of the next is the step length (just to clarify ).

[vilnoori]

One quick way is to take a picture of your own track in the same substrate in which you find a possible sasquatch track. That way you are dealing the a known as well as an unknown, in approximately the same substrate. I say approximately because as time passes the soil or sand dries, firming it up. So for example,

My print, ladies size 10, I'm 280 pounds (yup, I'm a big gal):




Here's a black bear track in the same stuff, same day:




And here's a possible sasquatch track, again, same place, same day:



Taken in November at a remote location, a barefoot person would be a really unlikely explanation of this track.

[Searcher67]

I did this about 3 years ago Paul, but then never really did anything with it. I measured the length, ball width, and heel width both weight bearing and non-weight bearing, then made casts in some nice squishy mud. It'll take some time to find the measurements but I'll try to get that up for you Wednesday.

One problem I had though, is that I measured the length of my foot on top of a ruler with my heel against the wall...that was wrong for what I was doing, since the back of the heel that projects out isn't part of the track/print/cast. If we measure a wet footprint on the cement, that wouldn't really be accurate either if the foot sinks more than a millimeter or two into the substrate. So, can anyone suggest what might be the most accurate way to take a foot measurement that would most likely correspond to the part that would actually make the imprint?

Hope that makes sense. I've been 3 nights in a tent and am slightly sleep-deprived.
Of the same foot (ie. right heel to right heel, or complete two steps). From the heel of one foot to the heel of the next is the step length (just to clarify ).

Stride length = from heel of left foot to heel of right foot

[Grazhopprr]

I personally don't know of any forensics professors, who will be out there when you find prints, to do the necessary measurements and dirt analysis. Every single print, will be in a miriad of types of soil, with hundreds of properties of compaction, flow, distribution, weight, stride, speed, etc etc etc. Even steps by the same feet, will go over differing types of sand, within a few strides. Many casts of the same track, have come out different looking, because of the soil change over a few feet of the same sand bank. You can't use a consistent layer of beach sand, and your own feet, in that kind of controled environment, to calculate a base model, for use in the field of infinite conditions. Even making your own barefoot track, next to a BF track, has time to contend with. The condition of that sand might have changed since that BF made that track, and using your own measurements as a control, isn't useful. At best, you're coming up with an average guesstimate.

This post has been edited by Grazhopprr: May 25 2009, 08:23 PM

[StacyInMI]

Stride length = from heel of left foot to heel of right foot

No, that is step length. Stride length is from heel to heel of the SAME foot. Trust me, it's part of what I do for a living.

[Searcher67]

No, that is step length. Stride length is from heel to heel of the SAME foot. Trust me, it's part of what I do for a living.

Well, maybe I wrote it down wrong, but according to Jon Vinroot I have written heel of one foot to heel of other foot.. I'll have to take your word for it, because now I'm confused!

[GuyInIndiana]

And Jon Vinroot is ... ?

[Searcher67]

A professional tracker trained by Tom Brown....

[GuyInIndiana]

And Tom Brown is... ?

See how long and boring this can become. Instead of name dropping or 'stuff', why not just look it up yourself?

[Night Stalker]

And so . . . Paul1968UK stated that his imprint in sand was 2cm larger than his actual foot.

While his foot was on the ground and load bearing? Or just horizontally but not with weight on it? Or sitting down?

What if one measures their foot on solid ground by stepping on a tape measurer not against a wall, and as described my StacyInMi. Then measure the <toe to heel> distance of a foot while making the imprint, then measure the imprint after the foot is removed. At what point are these measurements not the same?

[Searcher67]

Name dropping? Look it up myself?

Tom Browns tracking school...I guess you could look it up.....Sheeeesh

[Grazhopprr]

"Harumph, Harumph, Harumph,,,,,,,,,,,,,you over there, you're not Harumphing!!"

[Painthorse]

I'll give it a try. My son wears a size 15 also Paul, 6'4" and weighs approximately 220lbs. I can't break the boy from walking barefoot when walking the dog down the road and his bare footprints kinda look like some of the squatch pics, lol. I'll cast his foot print and post, along with pics of prints found in the same general area along with castings of bear and a possible juvenile squatch. Same area and same soil composition.