“Body tension follows fascial lines and the concept of tensegrity. The more tension created by the body, the faster you can stabilize joints, generate force and improve performance”
– Barefoot Strong by Dr. Emily Splichal
The word ‘tensegrity’ is an invention: a contraction of ‘tensional integrity.’ Tensegrity describes a structural-relationship principle in which structural shape is guaranteed by the finitely closed, comprehensively continuous, tensional behaviors of the system and not by the discontinuous and exclusively local compressional member behaviors. Tensegrity provides the ability to yield increasingly without ultimately breaking or coming asunder”
– Richard Buckminster Fuller – Synergetics p. 372.
You can find many images of structures utilizing principles of tensegrity in a web search. The graphic below is of a model I made years before I had ever heard of tensegrity. Note the shear forces, Fs, resulting from compression-tension in the arches of the foot. The shear forces provide the reaction force for the isometric chain that sets up tensegrity.
“Vibrations are damped through isometric contractions.”
“Previous theories on impact forces and overuse injuries relied much more on eccentric muscle contractions and joint mobility. The research of Dr. Nigg from the University of Calgary has since challenged this concept.”
– Barefoot Strong by Dr. Emily Splichal
The SR Stance imparts a state of tensional integrity in the entire body in a bottom up manner emanating from the plantar foot and extending to the shoulders. The SR Stance configures the angles of joints of the ankle, knee and hip with the associated muscles in isometric contraction. The process of setting up a static preload in the Achilles tendon is actually setting up a state of isometric contraction in the first link of the isometric chain, the soleus.
“What we will soon find out is that it is not the impact forces that are the cause of injury; it is actually a flaw in how our body perceives and responds to these impact forces.”
“Although we associate and perceive impact forces as pressure, we actually perceive impact forces as vibrations. The vibrations caused by ground reaction forces are set at a certain frequency that our muscles are programmed to.”
– Barefoot Strong by Dr. Emily Splichal
By 1980, I had reached the conclusion that the forces required to constrain the foot to a ski must be localised on the dorsum of the foot and substantially perpendicular to the transverse aspect of the ski base in order to maintain a load reference with the plantar foot. Although I did not fully understand the implications, I had concluded that boot boards that were not integrated into the base of the boot shell acted as insulators of vibrations from the ski. Foam boot boards are especially bad because they damp vibrations.
At the time that I conceptualised the in-boot dorsum restraint system disclosed in US Patent No 4,534,122 (Aug, 13, 1985), there were still significant voids in my knowledge. The device, in combination with a cast in place, torsionally and flexurally rigid carbon fibre boot board, was first used by Canadian Crazy Canuck, Steve Podborski, to compete and win on some of the most challenging downhill courses on the World Cup circuit. That he did this less than 4 months post reconstructive ACL surgery was nothing short of a miracle. Although I had based the technology on my untested theory that it might reduce stress on the knee by damping load-unload oscillation, I was both surprised and perplexed by Podborski’s ability to even ski with a knee in such a fragile condition, let alone with minimal pain or discomfort. I now know why. By sheer luck, it appears as if the components I had put in place in his boots must have had the correct vibration frequency to allow the muscles in his legs to damp vibrations and protect his knees.
THE EMERGING REVOLUTION UNDERFOOT
After centuries of damaging feet and causing knee, hip and back pain with the associated suffering, an age of enlightenment is finally emerging with the potential to lift the artisan design of footwear, of which the modern plastic ski boot is arguably the worst example, out of the dark ages. That this is finally happening, hit home recently when I discovered the brilliant Dr. Emily Splichal and her book, Barefoot Strong.
Dr. Splichal’s teachings will challenge everything you THOUGHT (past tense) you knew. She confirmed and clarified concepts and theories that I have mulled over for decades. In reading her book, it was if a bright light suddenly illuminated what had been cloaked for centuries in the darkness of ignorance.
Dr. Splichal has gracously given me permission to reproduce excerpts from her book. But she has done such superb job of articulating the subject matter that I would end reproducing the majority of her book if I were to reproduce every important statement. So I urge those who are reading this post to obtain a copy of Barefoot Strong so I can simply direct readers to the appropriate page and paragraph number in order to facilitate dialog. Here are a few more passages from Barefoot Strong.
“What we will soon find out is that it is not the impact forces that are the cause of injury; it is actually a flaw in how our body perceives and responds to these impact forces”.
“Although we associate and perceive impact forces as pressure, we actually perceive impact forces as vibrations. The vibrations caused by ground reaction forces are set at a certain frequency that our muscles are programmed to.
“As we put on shoes, socks, orthotics we begin to block the plantar receptors, skewing our perception of how hard we are striking the ground”.
The problem? Shoes and even socks block the thousands of small receptors in the bottom (read: plantar aspect) of the foot. What’s worse? Cushioning and extra support in shoes decreases foot strength.
A perfectly fit, tightly constricting ski boot that applies force to all aspects of the foot and leg with arch supports or orthotics that block plantar receptors is the worst possible scenario. More than just circumventing the plantar receptors, it prevents the damping process by bypassing the foot and the portion of the leg encased within the structures of the boot shaft thus acting to transmit forces from the snow up the vertical column with no damping. This objective is clearly stated in patents of which the excerpt below is but one example:
“During skiing the sole of the ski boot is rigidly connected to the ski by a ski binding. As a result, the ski boot acts as an interface between the ski and the lower leg of the skier. In order for the reaction of the ski on the surface of the snow to be transmitted immediately and accurately to the lower leg, and conversely, for the control exerted by the skier on the ski via the lower leg and the interface also to be transmitted immediately and accurately, the foot and lower leg must be held perfectly snug by the boot.”
– US Patent No. 6026594A
Given the importance of tensegrity in stabilizing joints, generating force, improving performance but especially, protecting the structures in the foot and vertical column from injury, the current trend in making boot shafts more upright to encourage skiers to ski in a more upright, relaxed stance should be deeply concerning especially in view of consistent claims that ski boots maximise energy transfer.
In my next I will discuss how footwear caused such long lasting damage to my feet as a child that I am only now through a protracted effort finally achieving a degree of normal foot function. After this post, I will continue to discuss Dr. Splichly’s work in the context of THE EMERGING REVOLUTION UNDERFOOT that has made mininal shoes a billion dollar and rapidly growing segment of the footwear industry.
Dr Emily Splichal is a Podiatrist and Human Movement Specialist. She is the Founder of the Evidence Based Fitness Academy (EBFA) and Creator of the Barefoot Training Specialist, Barefoot Rehab Specialist and Bare Workout Certifications for health and wellness professionals.
I am forever indebted and grateful to Dr. Emily Splichal for the wealth of knowledge she has transferred to me that have renewed my passion and made my efforts of the past 40 years worthwhile. Thankyou Dr. Emily Splichal.
Her book, Barefoot Strong is available in print and ebook formats.
DEDICATION in Barefoot Strong
“For those who have the courage to step out
of their comfort zone and challenge the
Alway’s push past life’s challenges, fulfill your
dreams and live a life full of passion”
To which I would add……… live a life full of passion and purpose.
Do not simply aspire to be