I read recently that Dr. Meldrum theorized that the double ball may be a bunched pad. This motivated me to try to provide evidence which demonstrates why I think this explanation is probably incorrect. Footprints provide clear evidence for the underlying structures of the foot. To me, the double ball evidence is interesting and compelling. I think Dr. Meldrum is probably very qualified and respected in his field but I think he may be lacking in some biology and engineering principles. I was reluctant to post this because I know Dr. Meldrum is a popular figure but I am fairly convinced that there are certain things that were not adequately taken into account by Dr. Meldrum’s in his foot reconstructions. The attached foot reconstruction shows Dr. Meldrum’s theoretical bigfoot foot on the left and a typical human foot to the right.

Because I was not satisfied with Dr. Meldrum’s and Dr. Krantz’ reconstructions, I had previously posted my own theoretical bigfoot foot reconstructions but I doubt that my previous attempts were very convincing. I suspect most people in the bigfoot community have not really looked into this issue very far and have deferred to Dr. Meldrum’s or other’s expertise. So I thought I might try a different approach based partly on my engineering background to demonstrate why I believe his reconstruction would not be suitable for a bigfoot.

The late Dr. Ivan Sanderson pointed out over 30 years ago that a bigfoot should have a large ankle relative to a human because it is a much larger animal. He suggested that a bigfoot should have a steep angled forefoot for the same reason. This was a concept that I have not forgotten, nor is it a concept that I can ignore. It is rooted in engineering principles that must be adhered to.

I decided to try a simple analyses using very basic math and engineering to see if I can provide an argument why the foot bones in Dr. Meldrum’s (and Krantz’) reconstructions do not adequately account for the great size of bigfoot nor do they adequately account for the double ball which is present in many if not most prints. My engineering is a little rusty but fortunately I only need to use very basic principles and common sense.

It may at times seem that I am just throwing out numbers and assumptions out there, but I am trying to be conservative and brief. I am not asserting that the following argument can predict the exact structure of a bigfoot foot since it obviously requires an exceedingly complex balance of size, dynamics, strength, weight, etc. to have the ideally adapted structures. Anyway here goes:

My initial assumptions include:
1. Bigfoot are reasonably athletic, at least equal to human. I think they are probably more athletic based on reports, but for the purposes of this comparison, I will conservatively assume they are equal to humans pound for pound.

2. My hypothetical male bigfoot is 8.5 feet tall and 800 pounds. I believe this to be a conservative weight based on reports and depth of footprints. I am assuming its foot is 17.5 inches long. There are smaller and larger ones, but this is the size I am arbitrarily assigning to a large male.

3. For comparison, my hypothetical human is 6 foot tall and 200 pounds

4. The strength per square inch of joint surfaces for humans and bigfoot should be roughly equal since the strength of bone is also roughly the same regardless of the mammal. For this discussion, I will only be referring to the relative load bearing stresses and assumed strength of the ankle joint determined per square inch of joint surface. I could have just as easily used thickness of femur or something similar but I wanted to discus the foot bones so that is why I chose the ankle joint. In addition, the load bearing forces on the ankle joint related to weight are essentially vertical.

5. To simplify, I will only consider the vertical forces related to weight. I will assume that the human and bigfoot are standing still on one foot while rubbing their belly with one hand and patting their head with the other (Sorry, my brother Bob told me to say that; really they are both just standing on one foot, twiddling their thumbs) (Stresses on the bones that are involved in movement, i.e. walking, running, jumping, are very complex and I will not consider them here.)

6. The average human should have a foot length of approximately 15 per cent of their height (I got this number from a forensic site) and therefore the average 6 foot human should have a foot length of about 10.8 inches.

7. To simplify, I am assuming the ankle joint surface of humans and bigfoot are square and are oriented horizontally which of course they are not. Just for ease of comparison, I will assume a 6 foot tall 200 pound human male has an ankle joint that is 2 inches by 2 inches (4 square inches). This is a somewhat arbitrary number but the relationship is linear and it won’t matter which numbers I use for dimensions of the joint as long as they are relative and proportional. In this instance, I am not trying to calculate actual forces, just the relative vertical forces involved between human and bigfoot ankle joint while taking into account my other assumptions. The 200 pound human ankle joint supports 50 pounds per square inch (200 divided by 4) in this example.

8. For ease of mathematical comparison, assume the 200 pound man is 2 feet wide and 1 foot thick though obviously the real dimensions are more complex than this. This man’s volume is 6’*2’*1’ which is equal to 12 cubic feet. Each cubic foot of this 200 pound human therefore weighs 200 / 12 = 16.7 pounds.

9. An 8.5 foot proportional man is 2.5 feet taller than the 200 pound man but would actually be almost 3 times as heavy. Dividing 8.5 feet into 6 feet results in 1.42. The 8.5 foot proportionate man is 1.42 times as long in each dimension relative to the 6 foot man and he would therefore weigh 8.5 * 2.84 * 1.42 * 16.7 pounds (=572 pounds) which I will round to 572 pounds. The proportionate 8.5 foot individual has a proportionate foot length that is 15.3 inches long and has a ankle joint that is 8 square inches ((1.42 inch * 2) inch)*(1.42 * 2inch) = 8.1 square inches, almost exactly twice as much as the 200 pound man; however, he weighs almost three times as much. The 8.5 foot man therefore bears nearly 572 pounds on his 8.1 square inch ankle joint surface or 71 pounds per square inch. Even though he is exactly the same as the smaller man in proportion to height, the forces on his bones are much greater.

The first thing I decided to do was simply measure the Dr. Meldrum’s foot reconstructions of the human and man (on the right). I measured the ankle joint surface on the human and extrapolated for a foot that was 10.8 inches long. I calculated a surface area of 1.8 square inches for the human ankle joint. This means that the ankle joint of this hypothetical 200 pound human supports 106 pounds on each square inch of joint surface.

Next I measured the ankle joint surface on the Bigfoot and extrapolated for a foot that was 17.5 inches long. I calculated a surface area of only 4.38 square inches for the Bigfoot ankle joint. This means that for the 800 pound Bigfoot, 182 pounds per square inch or 1.71 more weight is on each square inch ankle joint surface. This would be equivalent to the 200 pound human suddenly weighing 343 pounds. You can see this would put a tremendous strain on the bones.


I am having some trouble attaching a GIF. I will try later

The attached Gif shows how I believe Dr. Meldrum’s foot bones should be modified. (I believe that you have to click on it to activate GIF). I probably should have left the little toes bigger but I grouped the whole toes as a set. The point was to visually show which bones should be modified in my opinion.

What about the 8.5 foot tall 800 pound bigfoot that is our hypothetical example. In order for the bigfoot to have an ankle that is proportionately strong relative to the 200 pound man, its ankle must support 50 pounds per square inch. The 800 pound bigfoot therefore should have four times the joint surface of the 200 pound man (800 lbs divided by 200 lbs); therefore his ankle joint surface must be 16 square inches which amounts to 4 inches per side, twice as long in each dimension as the 200 pound human. If bigfoot had a foot that was proportional to the 200 pound human relative to its weight, its foot would also be twice as long or 21.6 inches long.

Yet in accordance with my assumptions above, the 800 pound bigfoot has a foot that is only 17.5 inches long. Obviously the bigfoot foot is not proportional to the humans. So how can we modify it without weakening it? In order to consider this as a simple math problem, I decided the break the length of foot into five units as shown on the picture below.

A = heel length, from talus to end of calcaneous (heel bone)
B = the length of the talus (ankle bone from top of talus including ankle joint surface)
C = length of midtarsal bones (navicular, cuniforms, cuboid).
D=length of forefoot (metatarsal), in dispute; it is what I am trying to figure out.
E=length of toe
Therefore A+B+C+D+E= foot length= 17.5 inches

To put numbers in the formula, and calculate for D, I measured a typical human foot and put the percentage of foot length for each category on the attached table. The table includes the relative lengths of A, B, C, D, and E for 10.8 inch long human foot, and the proportionate 21.6 inches long foot, and the hypothetical bigfoot foot that is 17.5 inches long.

The following provides an explanation for solving for D, the length of the forefoot (metatarsal bone, (just the one behind big toe to simplify)).

A We can’t shorten the heel because as Krantz famously pointed out, the heel length needs to be increased to provide additional leverage in a large biped; therefore heel length = 2.16 times 1.33 (a third bigger) = 2.87. This was arbitrarily assigned and is believed to be conservative based on the protruding heel on Patty and the needed extra leverage for a large creature.

B We can’t shorten the ankle joint (talus) because this would result in a weakened ankle (Remember the ankle must be twice as long (in width and length) to support the 800 pound weight). The ankle joint surface is only a part of this (talus) but I will assume that its relative length remains consistent therefore it equals 5.4 inches (from the 21.6 inch foot in table) since it must have equivalent joint surface to maintain similar strength.

C We could shorten the mid tarsal ankle bones including the Cuboid, Cunniforms, and Navicular however, since these bones are already short and are load bearing, I would expect them to be relatively increased in a large animal to maintain the same degree of support. Nonetheless, to be conservative, I shortened them from the 3.2 to 3 inches.

D This is the length of the forefoot or metatarsal and is what I am calculating for.

E The toes could be shortened but these features can be measured with a reasonable degree of certainty from the foot prints and they seem to be relatively proportional to humans. The toe length should be from the end of the to to beneath the first pad. Length of toe bone from Krantz’ reconstruction proportional to a 17.5 inches long foot is 3 inches

Therefore A+B+C+D+E= foot length= 17.5
2.8+5.4+3+D+3=17.5
D=17.5 - 2.9 - 5.4 – 3 – 3 =3.2 inch metatarsal. This number is mere speculation and based on a number of assumptions but it compares to 5.4 inch metatarsal that would be expected from the table if the foot was proportional to a humans based on weight. It turned out that the metatarsal was shortened by 59 per cent. Shortening the metatarsals makes good engineering sense also. By shortening a beam, it is less likely to break. A shortened metatarsal can also account for the double ball. Since the ball of our foot is a joint structure, it seems like common sense that the double b*lls on bigfoot feet represent separate joints at opposite ends of the metatarsal bone yet both Krantz and Meldrum failed to see it that way but then again, both failed to increase the ankle bones to account for the probably greater weight.


I placed the attached figure to show footprints with the double ball.

In Dr. Meldrum’s bigfoot reconstruction, the Tarsal Metatarsal (TMT) joint (between the toe and metatarsal) does not lie beneath the ball In humans, the TMT joint is the ball of the foot and it lies beneath a pad. Dr. Krantz does put this joint beneath the first pad of the double ball. Why Dr. Meldrum thinks a joint on a bigfoot foot would not lie beneath a pad is a mystery to me. Dr. Meldrum’s toe bones would be far more likely to break than a human’s because the forces would be correspondingly far greater on a long toe. I believe the pad beneath the human ball is used to distribute the stresses of walking on the TMT joint . Notice the ends of the metatarsal bones are thicker at the ends. This is because the joints are where the greatest stresses would develop and to compensate the bones are larger at the joint surface. As these joints bend there must be a pad beneath them to redistribute the forces over a larger area. Because bigfoot is huge, its need for pads beneath the joints should be even greater. I don’t think putting the TMT joint between the pads would provide adequate protection.

Impressive !!!

Good posts and observations, Jim.

Why don't you forward this to Meldrum and get his thoughts? I'd like to hear what he thinks of this.

Jim has offered a critique of my foot reconstruction that raises some interesting points, while suffering from a few misconceptions,. I will respond briefly to these in general and then I may be able to follow-up at a later point when I have more time. First, the reconstruction itself is taken out of context. It was never intended to accurately depict proportions of the individual bony elements other than their lengths. The object was to convey a sense of the the disproportionate lengths of the foot segments in contrast to the human foot skeleton. So the discussion and suggested enlargement of the talus is warranted and welcome. However from that point several misconceptions creep in as a result of a lack of familiarity of the biomechanics and functional morphology specifically of the hominoid foot. The transformed skeleton offered by Jim disrupts the obvious correlation between specific bony landmarks and contours of the footprint -- the most telling being the navicular which correlates with the convexity evident on the medial side near the ankle. Significantly, this is related to the midtarsal, or transversetarsal joint involved in the midfoot flexibility evident in the sasquatch foot and responsible for the occassional midatrsal pressure ridge. Move it and the correlation to the pressure ridge is lost as well.

I am quite confident in the reconstructed length of the toes as these proportions are not only borne out in numerous examples of footprint casts, but they are now clearly evident in the P-G film subject when the toes are seen dorsiflexing during the swing phase of gait, as seen in the split-channel images generated by Rick Noll and studied by MK Davis. These toes are not more likely to break, due to the behavioral modifications of the gait of the sasquatch so often reported by witnesses -- compliant gait, with increased period of double support, and push off from midfoot rather than toes. The double-ball feature is not evident in nearly all footprints as Jim asserts. In fact, it is only prominent in a few individuals, which seem to have a more extensive sole pad that extends more distally beneath the toes. Here again, this is borne out by the P-G film, which affords not only a view of the sole of the foot, confirmed by the casts, but now by a view of the dorsum of the foot and clear indications of the proportions of the toes as they dorsiflex.

As for the ball, Jim's description gets a bit confused. It is the metatarsophalangeal (MTP) joint that we are interested in. The toe begins here, not at the tarsometatarsal joint. In my reconstruction of the foot skeleton it does lie beneath the pad formed by the very thick anterior solepad. There is not a well differentiated ball demarcated from the heel pad by an arch. The entire sole pad is thick. The crease exhibited by this particular individual (the reconstruction is based on the filmsubject's foot) lies beneath the joint, just as you have a crease across your palm just beneath the metacarpophalangeal joints of your knuckles. Indeed, if you look at your inked footprints on your birth certificate, you will find that all humans start out with a flexion crease across the ball of their foot beneath the hallucial MTP joint that is generally lost as the ball fills out. I have examined cases of hypermobile flat feet that have retained the flexion crease into adulthood.

Well, I have already spent more time on this than I intended. Suffice it to say that the implications of foot scaling in terms of accomodating the large body mass attributed to sasquatch should be addressed not only by mechanics, but also by kinematics. If the mechanical properties of the materials are insufficient then some accomodation must be made with behavior. Condisering the texture of the habitat, the observed locomotor behavior, the fundamentally hominoid bauplan, the sasquatch foot is an excellent case of form-to- function.

I've attached a PDF of a paper that addresses some of these issues and places them in a broader anthropological context.

Thanks, Jim for bringing these issues to discussion.

Best regards,
Jeff Meldrum

I am floored with all the info provided by this board.

Wife says I need to get out more. :new_weirdsmiley:

thanks Jim and Dr. Meldrum.

Dr. Meldrum, I was very happy to read your response. Since I do not have your expertise in foot anatomy, my interpretations could easily be "misconceptions." Unfortunately I too am somewhat pressed for time but will try spend some time later tonight to respond to some of your points and the pdf in greater detail. I look forward to reading any of your future posts. Thanks for your response.
Jim Zenor

Good to see you here Jeff!

Kathy

I realize the foot structure can be a little mysterious to some (me included) so I thought I would try to use the GIFs to help explain what I am talking about. It will take more time but ultimately I think a picuture is worth a thousand words (I think you need to click on the GIFs). I think it will help explain the difference of opinions (or my misconceptions). The attached GIF shows Dr. Meldrum's reconstructed foot overlapping the Laverty photo. It is my understanding that he believes the bigfoot foot flexes at the transversetarsal joint (aka mid tarsal break) indicated by the line and that this flexion is responsible for the ridge. The ridge in the middle of the Laverty print fits pretty nicely where he placed the joint. The midtarsal break is at the bottom of the green bones.

I think a simpler explanation for the formation of the Laverty print is flexion of the Tarsal Metatarsal Joint which is also shown as the black line GIF below. As I have stated before, I believe it is also possible that there is flexion at the midtarsal break. My modification is very crude and was not intended to fit perfectly. I used it primarily to show the location of the joint. I realize that it might not make sense at first but I will explain later. I have done a previous reconstruction with a GIF that shows this feature and how I think it is probably formed but I am not very satisfied with it so I have decided to try to improve it but it may take some time.

Jim,

This is an interesting analysis and I applaud your effort- as usual. I can't even begin to touch on most of what Jeff has said regarding biomechanics and kinematics but want to point out the most obviously problem that occurred to me on a quick read.

It seems like one of the major premises you started off with has to do with the surface of the joint, i.e. size of the the talus, and certain assumptions about how big or small it must be to support an animal of such assumed weight. While this reads as reasonable, I have to question it's validity. For example, what is the range of possiblities? How big or how small could this surface area really be? What are the actual physical limits for bone compression? Are human ankles actually "overbuilt?" They may not be the best example even if if they are presumably the closest relative. What about other apes? Other animals in general? What is the known range for existing humans including human morphs ranging from Verne Troyer to Calista Flockhart to Andre the Giant?

I don't know any of the answers to these questions, but they would seem necessary to properly make the argument you have outlined. They might help it, or they might hurt it, again I don't know. Ignoring the obvious biomechanical differences, think of huge animals like horses, and how much weight is supported by tiny interphalangeal joints (sometimes one at a time while running or only two at a time while standing on hind legs).

I'd like to see this point of the thought process fleshed out before putting much stock in the rest that follows. Simply scaling from an average hypothetical human form, while certainly illustrative, doesn't really capture the range of possibilities. But I also realize that this was just an excercise and what I'm talking about greatly complicates matters.

And my old caveat- I'm not trying to be a nit picker or simply start an esoteric debate. I think we all need to be careful and consider how easy it is to lay 'truths' in this forum and how dangerous that can be. We all know that if Jeff hadn't responded, some in this forum would at some point be talking about how Jim disproved Meldrum's analysis. There are countless examples of that here. That's not intended to disparage you Jim in any way. I understand what your intention was here and assume you expected critiques. I'd simply advise everyone from overly interpreting excercises like these until both the critiques and the debates have played out. We should all remain as skeptical as possible on both sides of every issue.

And yes, that's part of the fun and beauty of this forum, luckily for us!

Apeman

Well, in the interest of time, I decided to only modify the previous GIF slightly by adding an arrow showing where the ridge is. My GIF does not show a sharp ridge, but I think with a little imagination you can see how a ridge like that is possible. This is a foot that is walking similar to how humans walk and in my opinion similar to how Patty walked. It is walking heel first, then weight is born progressively forward on the foot in a rolling motion. Notice that the forefoot is the last to be lifted from the ground after it thrusts backward. I believe the ridge is formed by first being flattened into the ground and then later pushed up as the forefoot bears more weight and is thrust backward. Notice also that there is a pad beneath the foot behind the joint effectively pushing the ridge further back than the actual joint. This is why I think the double ball is so important. In my reconstruction, it shows where the ends of the metatarsal bones are (the ones previously in blue). It corresponds to where the foot bends and where the most stress would be expected. When I first made this animation, I expected to find that the mid tarsal break (MTB) was most important but after doing them, it is hard to figure out how a bend at the MTB in a normal walking individual could result in the ridge. It seemed that it should be back further. I suppose there is a possibility that in this print, it somehow flexed it foot in a grabbing motion and forced the soil into the ridge but this is not a very satisfying explanation. I suspect Dr. Meldrum has a good explanation but I am ignorant of it. I am a geological engineer by training and a geologist by profession. As a geologist I have logged thousands of soil samples. Part of logging soil samples, involves determining plasticity. The soil where the laverty prints were formed looks somewhat plastic to me but obviously you can only tell so much by looking at a picture. To me it certainly appears consistent with the theory that iit was flattened as the foot rolled over it and then raised up as the forefoot thrust into the ground as it supported more weight and pushed backward. The features that are most telling to me are the cracks formed in the ridge. I am certainly willing to admit that I may have some misconceptions because I am no expert on this stuff. I clearly acknowledge that Dr. Meldrum among others is. I am just an interested amateur trying to understand something that doesn't make complete sense to me.

Edited due to obvious need to get to bed

Apeman wrote "Are human ankles actually "overbuilt?"
I suppose I should have provided this as a condition. I would expect that things should not be overbuilt too much in order to conserve resources and weight. I was just providing evidence that I thought the bigfoot joint surface was weaker in load bearing strength with some conditions. Other forces also play on the bones and these forces might have resulted in "overbuilt" bones so this is certainly possible. The problems that occur much more with overweight people might provide some argument that they are not that overbuilt but obviously there would be many possible explanations.

As students of biology we all know this is a good guiding principal. The problem is that it isn't always true, at least not 100%. This is why plenty of grossly overweight or simply oversized people can walk around and be pretty healthy and not have broken ankles. Of course plenty of them do have serious joint problems because of the stresses we're talking about, but not always.

My point was really more about "what is the range of normal variation" or "what are the physical limits." I agree that it is safe to assume certain biological efficiencies, and in fact, when it comes to biological scaling you could easily argue (or actually prove) that linear relationships aren't valid (i.e. that's why elephants have such comparatively fat legs), which might be a way to strengthen this idea of larger taluses??? Or was that what you actually did, Jim. Let me reread....

Apeman

Great thread guys enjoying it immensely

i think im catching about 50%....

metatarsophalangea?

fundamentally hominoid bauplan?? :new_weirdsmiley:

the navicular which correlates with the convexity evident on the medial side??? :icon_stressed:

:surrender:

back to Mr. Webster's thick book.....I always have it with me now before I start reading posts by the Zenors...but i think Dr. Meldrum one-upped them on this thread.

Nice animation of the footstep. First let me clarify two points before going further with this. One, you have superimposed the skeleton on a photo of the track taken from an oblique angle with foreshortening. There is a clear photo of the cast of that track in the PDF article. Second, the tarsometarsal joint (between the blue and green elements)of the foot, in humans or apes, does not flex. So unless you wish to propose a totally novel kinematic of the foot skeleton for sasquatch, let's set that notion aside for the moment. I could be off a little (but I don't think by much) on the placement of the midtarsal joint -- the metatarsals could be a bit shorter and perhaps the navicular tuberosity project a bit more proximally This would further reduce the bending stresses imposed on the metatarsals. But the green and blues parts of your foot figure effectively act as a single unit (sure there is some slight mobilitybetween elementsat points of articulation, otherwise the joints would be stenosed, but it is slight by comparison to the "midtarsal break" that is evident in apes -- and, I conclude, in the sasquatch foot).

I concurr with your assessment of the substrate and dynamics evident in the footprint. Spot on.

Take a look at http://ivl.imnh.isu.edu/SpecimenLibrary/foot1.html

This is part of an archiving project I am working on at The Idaho Virtualization Lab (IVL). It is lower resolution than the actual scan for the sake of the animation program, but it allows examination of the cast from various perspectives. You will notice the concentration of plantar pressure beneath the forefoot, just ahead of the pressure ridge.


Gotta run,
Jeff Meldrum

Hi Jeff,

Thanks for your comments, and especially for attaching the file so we could download "New Perspectives on the Evolution of Bipedalism."

I printed that out!

Scott

It is unfortunate that my scientific knowledge is so low that the only words I recognized were "Foot" and
"Toe". But it is wonderful to see threads like this pop up. Ones like this are real gems. Thank you to all for the information.

Glad I'm not the only one! I did like the pretty pictures and the one that moved...that was cool!

Sorry if I lost some of you. If you haven't seen this poster, perhaps it might help illustrate some of this discussion as well

http://www.isu.edu/~meldd/fxnlmorph.html





Edited to fix link.

Lets see if I can get my money's worth out of those two college semesters of human anatomy back in 1986....

metatarsophalangea: where the bones of the toes and the foot meet.
metatarsal: the long bones of the feet
phalanges: toe (or finger) bones

fundamentally hominoid bauplan: basically human type body plan

the navicular which correlates with the convexity evident on the medial side: The navicular bone is the highest bone in the top of the arch of your foot
convexity: means the way it bows outward (opposite of concave)
medial side: is the inner edge (or on the side facing the other foot, as opposed to the lateral side, which is the outer or away facing side).

Dr. Meldrum, Thanks for the information about your foot reconstructions. Admittedly, I haven't spent time in the past on this, but the skeletal reconstructions and the underlying structure that produces the midtarsal break now make perfect sense. As for the rest of all this, I'm gonna have to spend some time on this thread with a copy of Gray's Anatomy in hand. Cool!

Thank you for coming aboard and sharing this information with us Dr. Meldrum. I remember some of it from your discussion at the Texas conference. Absolutely fascinating. Thank you again for your time.

Mike

Much of the same ground was covered recently in this thread:

http://www.bigfootforums.com/index.php?showtopic=13850&st=0


Here's a correctly superimposed reconstruction on the Laverty photo (for whatever it's worth).

Click to view attachment

This has been a wonderful, educational thread.

Thank you Dr Meldrum for participating.

Funny thing about all this discussion, I still don't know how a mid tarsal break is supposed to form the Laverty print. Could someone please explain the exact way it is formed. Please include the hypothetical thickness of the sole pad, how the foot bends, etc. in your explanation.

Any ideas on the range of flexibility the mid-tarsal break might allow the Sasquatch foot to bend ?
From extreme convex to extreme concave.
Would this MTB work like a spring in leaping and/or running ?

Thanks Jeff I hadn't read this one before. Its really great of you to spend your time answering questions on our board.

xpert4u

I think that's okay as long as there are no finals.

" A totally novel kinematic of the foot skeleton for sasquatch .. " ?


I know there is something wrong with, or missing with that statement.. I just can't articulate it at the moment.

Maybe someone else can shed some light on it.

Meanwhile, if I come up with something I'll throw it out there...

Thanks califb, my fingers were getting sore flipping the ol' Websters.... :icon14:

Click to view attachmentClick to view attachment

The skeletal reconstruction was doen in one of Roger's casts, but fits well over Titmus' casts of the Laverty track, except for the toe splay. Like I said -- the TTJ could be nudged toward the toes a bit more perhaps, but otherwise the congruence is pretty good.

Click to view attachment

Here is another principal example in the Heryford casts.

I very much appreciate your response Dr. Meldrum. You provided me a few valuable nuggets of information, among them was that the tarsalmetatarsal joint is apparently rigid with the respect to the adjacent ankle bones in humans and presumably apes as well. I am curious just how easily these joints might become flexible but I am sure that would involve a lot of speculating. I also understand your point now about the Navicular which is possibly evident in some tracks. That certainly seems like compelling interpretation that I hadn’t realized before. Are these bulges strickly sole pad features or are they evident above the pad as well? Unfortunately, I am sure most footprint evidence is limited to the sole. I think you are probably correct regarding the sole of the foot being heavily padded. I wonder if it might be more padded on the areas where the foot bends because they are obvious stress points and whether those bulges could possibly correspond to the transversetarsal joint. My only encounter with what I think was a probably a bigfoot happened late one night near Bluff Creek. The most obvious thing that I gathered from that experience was from hearing the footsteps approach. Each step was agonizingly long and you could hear the feet roll along and crush the ground beneath them. That certainly biases me toward a very flexible foot so the idea of the flexible transversetarsal joint makes a lot of sense to me. I am still left with some doubt and questions but I have certainly moved toward your position. I still need to do some more research to satisfy my curiosity. Thanks again.

The joint surfaces of the TMT joints are quite planer, which restricts their flexibility to the degree of laxity of the ligaments of the joint capsule. In the hand the 4th and 5th metacarpals are capable of flexing, as when making a tight fist. But here the joint at the base of the MC4, 5 are a bit more concavoconvex.

A former student of mine conducted research on the sole pad in apes and humans and did an MRI study of a sample of feet. The chimps and gorillas showed a pad that was thickest beneath the calcaneus and tapered toward the MT heads. There wasn’t any differential thickening beneath the transversetarsal joint, at least not on the medial side of the foot. However it was considerably thicker in that region than in humans with an arched foot, where the sole pad was quite thin.

There does seem to be some differential thickening beneath calcaneocuboid joint, and that sometimes produces a noticeable bulge about that joint. You can see it in many human footprints and it seems to be evident in the Heryford example, and to a lesser degree in the Patterson cast outline.

The flexibility of the sasquatch foot is likely significant, and made more dramatic by the great weight of the sasquatch. Your impression of the foot “rolling” through the step is very interesting. One witness I spoke to was afforded a very close view of a squatting sasquatch and he noted the peculiar C-shape formed by the flexible foot with the heel elevated off the ground.

Click to view attachmentClick to view attachment

Here is a depiction of the plantar pressure recorded for a quadrupedal chimp. The hotter the color the higher the pressure. Note the midtarsal break, which concentrates pressure especially beneath the cuboid.

The image to the right is one of Cassies MRI of a chimp. We were looking not only at thickness, but also architecture of the connective tissue within the sole pad.

What an absolutely glorious thread!

Dr. Meldrum, Jim Zenor, and Apeman (been gone for a while) sharing information like the above.

Thank you, gentlemen. I'm lovin' it.

You are so right, Hunster... I couldn't agree more!

Yes... thank you gentlemen for sharing.

But it's too bad the title of this thread implies there are actually some problems with Dr. Meldrum's foot reconstruction model, when in fact seems to be incorrect, IMHO.

I do believe we owe Dr. Meldrum an apology for that bit of irresponsibility as it does give the wrong impression... again, IMHO.

I completely agree. To be consistent on this forum, this thread should have been titled: "Alleged Problems with Dr. Meldrum's Foot Reconstruct." However, to be more accurate, the thread should have been titled: "Caution...Big Words Used."

Amen to that!!!!! :icon14: :icon14: :icon14:

...and just when people start to doubt, and the skeptics arguments start to sound correct, a forum thread like this comes along and provides so much undeniable real science that supports existence.

Dr. Meldrum ....
Jeff !
I wanted to re-ask my earlier question, and forgive me if this has already been covered, but what is the proposed flexibility of a foot morphology like this ?
In Maximum range of motion ?
MTB at full concavity(?)... toes up...
and, MTB convexivity(?)... in a "gripping", toe-clinch ?

And, how would this MTB manifest itself in the animals' bi-pedalism ? Quickness... Speed... Climbing ?

Thank You, Sir !!!

"ELVIS!"

The thing that I respect most about Dr. Meldrum is that he has the courage of his convictions. He fits my definition of true scientist. It is easy for me to post here on the Internet, but he also presents his ideas in a very public way and at great risk to his reputation. I have only gratitude and greatest of respect for him but if I don't understand or agree with someone I certainly will not blindly follow. That would be disrespectful and dishonest in my opinion so I plan to continue to express any doubts, questions, or problems I have.

That was an interesting bit of research. Because the sole pad might be compressed at the joint, I wonder if it might also splay out a bit from the joint forming a slight lateral bulge adjacent to the joint. If not in a chimp, then perhaps in a thicker pad that a bigfoot presumably possesses.

Dr. Meldrum (if you're still here), I wonder if you would be willing to address this argument from Correa Neto on the James Randi Forum. I've asked him repeatedly to contact you with it but for some reason he hasn't, to my knowlege, done that yet.


"The futility of mid-tarsal breaks, once again.

Here´s how the torque equation indicates that bigfoot´s alleged feet anatomy is inneficient for a bipedal supposed to walk long distances.
Complexity and lack of efficiency when it comes to converting the forces created by the leg muscles in to movment.



Understood now? There are no "false premisses here". Just basic Newtonian physics.
Oh, the pic also answer to another question of yours.

And here´s a comparsion between real feet with mid tarsal breaks and alleged bigfoot footprints.

Note that the position of the toes in the apes are completely different from those shown at the alleged bigfoot footprints. Look at your own feet to see similar toe positioning.
Ape pictures came from [IMG]http://williamcalvin.com/portraits; bigfoot footprint images cropped from the bigfoot threads in this forum.

To sum things up, mid tarsal breaks are just another implausibility in bigfoot anatomy. And yet another reason why Krantz, Meldrum & Co. work on bigfoot fails to impress me - and many other people.

Oh, whenever I have some more couple of minutes of free time I will continue our debate regarding teeth shape and bipedalism.
__________________

http://forums.randi.org/showthread.php?t=4...ghlight=Bigfoot

And which cast is this? I'm trying to answer some claims on JREF, such as

"It doesn't seem to matter how bad the fake feet are though.

There are a few particularly bad fakes on Meldrum's page, a picture of John Green examining a particularly bad straight line of particularly bad prints, bear prints, etc., etc."

http://forums.randi.org/showthread.php?t=42523&page=74

and

"It's the wallpaper on his web site ...


Oh, I forgot for a moment.. .. That is the cast, that was a model for one of Wallace's feet;
right down to the crack in the heel ..


What is the the theory behind how a Sas got a scar like that ? Stepped on a machete that someone carelessly left laying around ?"

http://forums.randi.org/showthread.php?t=42523&page=73

e.g., but can't find a match for it. From the URL it would seem to be a Titmus cast, but which one? Is it one that was for sale near Bluff Creek that Wallace could have copied from? What caused the line?



http://www.isu.edu/~meldd/crypto.html

BTW, some of the links are dead.

LAL,

Sorry, but after taking a quick scan through the other lists you are participating in, I don't think it is worth my time to respond more than just briefly to the latest criticisms. They are of a different nature than the points raised by Jim. Neto clearly has no concept of the calculation of the mechanical advantage of the triceps surae (calf musculature) as evidenced by his comments and attempt to diagram his point. The model of the sasquatch foot is a very natural extension of trends displayed in a size-graded sample of ape feet from gibbons to chimps to lowland gorillas to mountain gorillas, not only in relative elongation of the heel but in lessened divergence of the great toe. Humans have departed from this pattern by adopting a fixed arch.

The MT break has little to do with the loss of divegence of the big toe, until the fixation of the arch, at which point the aligned big toe becomes the distal support of the arch. There are a number of interacting modifications at play during the evolution of the modern human foot. (Some people should do the research required before asserting their opinions with such conviction.)

The comments about the casts and footprints illustrated on my webpage and the comaprisons made between the Laverty photo are simply without merit.

The particular cast you asked about is one of Timus's casts.

Thank you for the reply. I agree JREF is mostly a waste of time, but getting my blood boiling before my morning coffee is just one of the ways I start my day.

Do you happen to know where the Titmus cast is from? I take it it's safe to say it's not one you purchased from Paul Freeman. :laugh:

My first encounter with "The Amazing Randi", was back in '91 at the Magic Castle in w. Hollywood, CA.
I was performing there (I was a Magician back then) & after my show one night we all sat around the bar & talked about the latest "HOAXES" that Randi had exposed.
I had not yet become interested in the Bigfoot Phenomenom back then & our discussions were about Houdini (my HERO!) & the debunking of FAKE PSYCHICS. I'm almost positive that the topic of Bigfoot never came up.
I really admired his common sense approach to 'the Mysteries of the Universe". He seemed to be a "No Nonsense" kinda guy....& I like that.
Now, ironically, I find myself at odds with him....not about Psychics & UFOs....but, about his insistance (via the Internet) that BIGFOOT is also a bunch of 'hooey'.
I joined his JREF discussion to argue for the validity of our Research..... however, as of today, I have yet to post on there nor have I read much of his board.
(too busy over here !)

My opinions & ideas aren't worth much here and, evidently, neither are my questions :icon_bang: , so maybe I'll give my ol' pal Randi a 'holler' & see if he thinks I rate any answers to my questions over there......

Evidently he's recovering from something and is unable to answer many e-mails. I haven't found out what's wrong with him yet. I've never seen him post on his own forum, at least under a recognizable SN. I hope you'll post, though. Hunster and I could use some company.

I loved his books and have been a Randi fan since I saw him on Johnny Carson, butI think he's way off base on Sasquatches, although he did take a "show me" stance in one of his articles.

I think your opinions & ideas are worth something here. Which questions specifically? (Some of us kind of cheated and PMd Dr. Meldrum. :new_whistle:)

LAL,
no biggie......... THANKS, anyway!

(check post @ top of page & my previous post on page 2 of this thread.)