When people come upon a suspicious track they might disregard them as being of modern human origin. One of the first things a data collector must consider is the context of the track. One should take into consideration the temperature, terrain, shoed tracks in area, as well as likelihood of human origin. Sometimes people will take off their shoes to let their feet breathe however, they wont stray far from hospitable terrain. You can also verify if someone has taken off their shoes by measuring the barefoot track and compare to the shoed track, a barefoot track is normally an inch smaller than a shoed track. I have heard many times that tracks are disregarded because of being within areas of human activity. If Sasquatch were never around areas of human activity then there would never be any reported sightings. This is a prime example of how some allow bias to overrule evidence presented.
Evidence presented should be assessed with the mind of a child. What I mean by this is that there is no preconceived notions of how things should be but rather allowing the evidence guide the collector. On one of the first trackways I came upon the first thing I noticed was where the location of the tracks as well as where they were going. The tracks were within human range but the anatomy, ratios, and flexibility were much different than I had seen in surgery. I had taken a Physician Assistant as well as another nurse to the site and all had agreed that they were not of modern human origin. We all worked together at that time specializing in Orthopedic surgery. What will follow will be images of the impressions and resulting castings of this particular area.
Here is an 11 inch track discovered above 10,000ft. Although it falls within human parameters, it is the ratios that first caught my eye. The first thing that stood out is how big the big toe was. I have seen a 2 1/2 inch big toe on patients but they were being seen for amputation from diabetic necrosis. The healthiest of these pts are crutch bound, very unlikely being at elevation. Now take notice of the angle of the toes, compare to your own. Do you see any difference? Lets move on to another track within the same trackway.
A few steps from the track above is this track. You can see it comes from the same track maker by that familiar large big toe. What is much different is the evidence of flexibility seen here. You can appreciate the Flexor Hallucis Longus by the dorsal hyperextension of the great toe. The remaining toes are curled up in a ball appearing as peas in a pod. So what we have is a foot with its big toe being hyperextended as their remaining toes being curled up simultaneously. Now I am sure you could probably find someone out there that can do this however the chances of someone with a toe that large with those ratios doing this above 10,000 ft across rough terrain is pretty slim at best.
Here is a side view to get a better appreciation of what is happening. Also take notice of how thin the mid foot is.
Here is a very good example of flexibility. The top two pictures show a reverse image of the impressions with the resulting castings below. The top two pictures show a lighter image for the deeper impressions. The metatarsal impression is very deep and narrow as if the bones were running vertically parallel at the metatarsal break. For a modern human to do this there must be a compromise in the joint capsules. The only logical explanation for this is very flexible tendons and ligaments. There would also have to be different origin and termination points of these tendons as well as collateral ligaments and tendons, even some slight differentiation in skeletal anatomy. Hormones like progesterone may also play a part in this flexibility.
Another example of flexibility. To the left is a very distorted and unfamiliar image. The word "Sierra Sasquatch" is the toes and the other deep impression is the heel. There does not appear as if there was any twisting motion in the heel at the time of the impression which would explain the toes being so far off. The only other explanation would be vertical flexibility as well as horizontal flexibility.