WHAT’S YOUR PQ? [PERFORMANCE QUOTIENT]


After my disastrous experience in 1977 with the mythical Perfect Fit with Crazy Canuck, Dave Murray (.1); one that transformed Mur from a World Cup racer to a struggling beginner, my work on ski boots became focussed on removing instead of adding material and making room to allow a skier’s foot to assume its natural configuration in the shell of the ski boot. As I improved the accommodation of a skiers’ neurobiomechanical functional requirements in the ski boot, skier performance improved in lockstep. I was merely reducing the structures of the boot that interfered with performance to enable a skier/racer to use the performance they already had.

Fit: The Antithesis of Human Function

Fit, by it’s definition of joining or causing to join together two or more elements so as to form a whole, is the antithesis (def: the direct opposite) of enabling the function of the human foot and lower limbs as one of the most dynamic organs in the human body. Fitting a ski boot to the foot and leg of a skier, especially a racer, equates with imposing a disability on them (2.). Although I didn’t realize it until I read The Shoe in Sport and learned of the barefoot studies done at the Human Performance Laboratory at the University of Calgary, my work on ski boots had transitioned from Fitting (disabling), by adding materials to liners to fill voids between the foot and leg and shell wall, to UnFitting (abling) by removing materials from liners and expanding and grinding boot shells so as to accommodate the neurobiomechanical functional requirements of the foot and leg of a skier.

But the big breakthrough for me came when Steve Podborksi won the 1981-81 World Cup Downhill title using the dorsal constraint system (Dorthotic) I developed and later patented. The Lange boot shells the device was used in had the least constraint of any ski boot I had ever worked with. The instantaneous quantum leap in Steve’s performance compared to the same shell using a conventional liner raised the question of how could a skier’s maximum performance be achieved and was there a way to compare to a skier’s performance in different ski boot/liner configurations to an optimal reference standard?

A reliable indicator that my un-fitting was trending in the right direction was that skiers consistently found that skiing became easier. For racers, coaches would typically report that the racer was skiing better. Improved race results served as further confirmation of my efforts. But these indicators were subjective. I wanted a way to not just measure performance with quantifiable metrics generated from data specific to the activity, I wanted to be able to compare the same metrics to a reference or baseline standard that represented the optimal performance of a skier or racer at a given moment in time. Without a way to measure and compare performance there is no way of knowing how a ski boot is affecting a skier or racer and especially no way of knowing how close they are to skiing at their maximum level of performance. I wanted to develop a skier Performance Quotient or PQ.

Definition of Quotient

  • Mathematics: – a result obtained by dividing one quantity by another.
  • a degree or amount of a specified quality or characteristic.

A skier Performance Quotient would capture baseline metrics from a skier’s performance in a ski boot that provides the optimal functional environment for the foot and lower limbs to the skier’s peformance in different ski boots including a skier’s current ski boot. The ski boot that provides the optimal functional environment for the foot and lower limbs would be designated as 100%. If the same metrics captured in a different ski boot were 78% of the reference standard, the skier’s PQ in the ski boot would represent a PQ of 78% against a possible 100% or 78/100.

Raising the bar of skier/racer function with body work and/or conditioning will raise the PQ. But it cannot close the PQ gap created by the performance limitations of the interference with neurobiomechanical function caused by their ski boot. Nor can trying harder or training more intensely overcome the limitations of a ski boot. Assuming 2 ski racers of equal athletic ability and mental strength, the racer with the ski boot that enables a higher PQ will dominate in competition. The only way to improve a skier’s PQ when it is less than 100% is to improve the functional environment of the ski boot.

In current ski boot design process, manufacturing and aesthetic considerations override skier functional requirements. An innovative approach to the design of the ski boot is needed. This is the subject of my next post.


  1. IN THE BEGINNING: HOW I GOT STARTED IN SKI BOOT MODIFICATIONS, May 12, 2013 – https://wp.me/p3vZhu-y
  2. LESS REALLY IS MORE, May 13, 2013 – https://wp.me/p3vZhu-N

 

6 comments

  1. A possible approach to establishing a skier baseline might be established on a Nastar course-as like golf, most people will race thru a course (using their own boots) and get close to a handicap limit based on their ability and equipment. So establishing what that handicap it is also your race baseline.

    So, race 1/2 day on your regular equipment, Establish your handicap, then switch to a new boot (all other equipment being the same) and race for the rest of day-if you consistently beat your handicap then you are on to something regarding the ski boot-If not, then most likely it is hampering rather than helping.

    If 10 people do this and get the same results, then you may be on to something….I think (yes I know 1 over square root of N in terms of margin of error)

    1. There are significant deficiencies in such an approach that I will address in future posts. A very significant issue is the lack of a device with which to identify what amounts to maximal performance/minimal constraint baseline metric with which to compare the effect of various ski boot structures in a controlled environment with controlled variables.

      1. There will be imperfections to all forms of measurement unless you are able to, for every tester, have the same conditions meaning every snowflake be at the same place and position, same temperature, same sunlight, etc for each person testing.  Of course one must define improvement: warmer foot?  More pressure in turns? Faster? All things considered, time is a good measuring tool compared to anything else out there. (In lab experiments are ok but no substitute for in field  testing.). I will be curious to hear your commentsptr

      2. The issue is to have the same conditions in terms of accomodating individual 3 dimensional joint articulations and neurobiomechanical requirements within the structure of a ski boot as well as mechanical references with the key mechanical points of the foot and ski. This is the level playing that enables skiers to be compared and their Performance Quotient established using date that generates quantifiable metrics. I will post on this issue in the future. For now I suggest you read SKI BOOT ASSESSMENT PROTOCOL, HOCKEY SKATE SMACK-DOWN, PROBLEMATIC FEET AND LEGS and SKI RACING: AN UNLEVEL PLAYING FIELD.

      3. OK, have read a lot  but not all of the manifesto I  have learned some, am able to contribute some, and have some questions.But i do see your appreciation of toe pressure and so hope you may a have an understanding of what I am saying regarding clenched toe pressure vs elevated toe pressure. We are talking about the skier having up to 100 % more pressure to manage with elevated toe pressure which my patent protects. If so and even if not (if i am missing something) I would very much like to get some advice as I am looking for someone to CEO up a kick starter type thing and whatever follows. I will through in the patent and some $ to get things going.  Please tell me if I am right to pursue such things or not.   And of course I respect your science bent so naturally expect comments backed up with fact.

      4. The first step (pun intended) to skiing that utilizes the existing sophisticated neurobiomechanical processes of balance and movement is the ability to balance the torques across the inside edge of the outside ski. Without this, unbalanced torques will be present in two coupled planes. In this situation toe pressure will have a negative effect.

Comments are closed.