Bigfoot: The Horizontally Dynamic Foot Theory

Horizontally Dynamic Foot Theory
By Karl Sup and Sharon Day
November 21, 2012

Humans have a vertically dynamic foot for upward lift. In this theory, we propose that Sasquatch have a horizontally dynamic foot for enhanced step grip.

Visual evidence in films such as Bluff Creek Patterson-Gimlin film (1967), show a creature whose body length is highly disproportionate with human beings, with powerful gluteus and leg muscles, wide hips, as well as a smooth, compliant gait that does not generate any head bounce. This evidence demonstrates that there is no “step off” in their gait, but instead the sasquatch maintain a knee-bent, ‘snow-shoeing’ compliant gait in which the rear foot and forefoot exhibit separate flexibility, often referred to as a mid-tarsal flexion break. This theory proposes that there is an additional shift of the rear foot towards the forefoot (or an inchworm effect), that can create a composite pinch of substrate or forest litter like pine needles and leaves.

In the instance of a human who is morbidly obese, his frame and gait cannot typically tolerate their excess weight. Instead of the typical push off on the ball of their foot, this individual will sway side to side (“waddle”), thereby wearing down his knee joints. But, in the instance of a very heavy creature perfectly designed for such weight, the hips are wider, the joints are very flexible to allow for a bent-knee, flat-footed gait, which in turn create enormous gluteus muscles, leg muscles, and a smooth “cross country skier” glide that is reported by those who have witnessed this gait.

Humans have an Achilles tendon to lever their foot for that push-off dexterity and it is entirely possible that Sasquatch also possesses a dorsal tendon on the bottom and side of the foot that allows for flexibility on the sole of the foot. 

There have been reports and video of Sasquatches performing what can only be called a rabbit run, where he goes down onto all fours, galloping with his legs up and around rotating like a rabbit’s. This flexibility is highly impressive, but this run makes a great deal more sense for distance covering and staying low and less visible. With the enormous amount of lower body muscle mass that Sasquatch possesses, the launch distance created by going on all four is an enormous leap, legs rotating to give even more momentum to thrust a long distance again. It makes sense both for the ability to remain lower and more hidden, as well as covering ground fast.  Sasquatch is also seen doing a “creeper walk” which is like a squat as if he is sitting in a chair and creeping his bent legs forward. This not only makes him much shorter and less noticeable in brush, but gives him a steady, albeit slow, silent stalking gait.

About the authors of this theory

Karl Sup is a software architect, developer and analyst, and an avid Bigfoot researcher working in the mountains of Arizona for many years.  During this research, he observed a pattern in trackways and prints where debris or pine needles were caught in the center crease of the prints that were “pinched” into place.  Karl’s two children, Jonathan and Kaitlyn, both pre-med majors in college assisted with details regarding anatomy/physiology and the overall feasibility of this theory.  Karl also has had decades of audio analysis and editing, and assisted in helping M.K. Davis clean up and enhance audio from VHS tapes he has been studying and discovered the presence of infrasound within those recordings.

Sharon Day is author of Ghost Hunting Theories and a paranormal enthusiast, co-author of the upcoming book “Paranormal Geeks.” She keeps herself well immersed in all things Bigfoot and is a medical transcriptionist by trade and from a family of doctors and nurses. An experience with a ruptured Achilles tendon and its reattachment had her thinking about Bigfoot’s gait.

(Undisclosed cave entrance in Arizona)

(Comparing height proportions in relation to ratio of leg length to total height)

This is not just a man in a suit – look at the proportions. "Patty's" leg length ratio when compared to her height is 1/3 of her final height. For humans, it’s more than 2/3^rd (see Sharon’s photo on the left)  It’s not only a disproportionately long body (if Sharon had the same ratio, her final height would be 96 inches instead of 68!), the gluteus muscles on the Bigfoot appear to be about 1/3 of its entire back height!

Here's a tribe that runs barefoot --

Look around the 13 seconds on time period at the foot falls -

(animation courtesy of MK Davis)

As an update-MK Davis has been running across evidence to point to this concept -


Thank you, MK, for looking for evidence to support our theory.