05 A Few Biomechanical Considerations

Abraham Maslow suggests that your need to sate your hunger or empty your bladder trumps your need to enhance your understanding of ski boots and their impact on performance.  In the same vein, your body needs to remain upright and stable wherever it finds itself, more than it needs to execute a clean wedge christie.  Most of the odd postural contortions seen on the hill are directly related to this need, which I refer to as ‘The Prime Directive’.  Once  the PD is satisfied, the needs move on to protection of the joints, and then to a reduction of effort.  From the viewpoint of the CNS, most everything else should be considered optional.

Conformation of the foot.

In order of prevalence, feet collapse either medially, laterally, or minimally.  The foot that barely collapses is most desirable, and yet rarely seen.  Most everyone else has issues…

A quality footbed should account for and reduce the effects of a collapsing foot, in effect, creating for each user the minority foot type.

Most do not, as this type of tuning takes time, and time is money.

Anything with contour that does not hurt, is a step in the right direction.  And feet do not commonly change shape every 4 years.  Most footbeds will, however, break down in that time.

The Back Seat

Effort should go towards understanding why a skier would ski ‘back of center’, rather than on trying to enforce a different posture.  The same should be applied to hand position. There is always a distinct reason for what may be viewed as aberrant behavior; for lasting effect, seek to treat the disease, rather than the symptom.  More often than not, a skier ‘back of center’ is working in opposition to boot/binding geometry that forces them to the front of the ski.  As soon as they begin to glide, they become unstable, and they seek a location of equilibrium.  They may not be agile in that position, but at least they are, in the moment, upright and stable. And, I might add, seemingly ‘safe’.

The psychology of fear does play some part in postural compromise, but I wager that if an individual did not feel somehow uncertain of their footing, they would not ‘shy away’ from gliding.  The emotional response would then be positive, rather than negative.  After all, while sledding is fun, sledding while standing is funnerer….

In short, take care of the boot geometry, and the posture will take care of itself.

Stance width

In simplest terms, your stance is determined by how well your bones stack up, and how much effort is required to maintain that stack. Typically, the lateral distance between the feet would be about ‘hip width’.   In practice, these two criteria also need to account for structural collapse of the foot, and how the skis meet the snow.  In order to acquire sufficient grip for stability, our stance may need to be wider or narrower than bio-mechanically ideal, such that the skis meet the snow in a ‘functional’ manner. Not every skier has ‘straight’ legs, so for everyone else, stance width is not terribly negotiable without some boot alterations. Sometimes this can be resolved with cuff alignment.  The quickest fix is to jam a few trail maps between the boot cuff and liner, on one side or the other.

Issues of ski/snow contact are readily seen during introductory telemark lessons.  This is due in part to the need to be effective on both skis at the same time.  Quite often the lead ski will have insufficient contact with the snow on its inside edge until it drifts away from the skier, while at the same time the trailing ski has too much engagement on the corresponding edge for similar reasons.

While the notion of ‘parallel shins’ in alpine skiing may seem like something to strive for, that geometric goal may not be feasible. Better to initially seek ‘equal performance’ from each ski.  In other words, you could achieve equality with your shins, and still ski poorly.

Asking a skier to achieve the stance width currently in vogue may turn into a lesson in futility, until you understand why they presently stand the way they do.

Skiing with the feet.

Much is said about skiing with one’s feet, though few skiers truly ski ‘out of the foot’.  It is a very fine line between a boot that is supportive, and a boot that is obstructive.  Block free articulations at the ankle joint, and you will inevitably find some other way to control your skis. Thus, the majority employs some combination of articulations at the knee and hip to engage/disengage their skis.

If the skis contact the snow at ‘odd’ angles, and/or the pressure distribution along their length is uneven, the skier will compensate by rearranging the body such that stability is achieved. Increased joint flexion generally increases muscle tension on that joint, and often on adjacent joints as well.  The effect is to ‘lock’ that part of the kinetic chain, at least until tension is released.

To say nothing about premature fatigue.

A skier in the moguls bobbing up and down at the waist with little leg flexion/extension likely has boot issues.

Canting is generally accepted as the angular relationship between the ski topsheet and the boot sole.  Canting may be used to great effect to remove leverage from the ankle joint, as well as mitigating the rotational tendencies seen of the lower kinetic chain under compression.


The less tension in the body, the greater the compliance to the surface. Ideally, the mass of the torso should not interfere with latent ski performance, nor vice versa.

‘Simple’ flexion/extension of the legs looks good on paper, but often fails in practice, which is to say, while in motion.  If the joints and musculature of the knee, hip, and ankle are devoted to compensating for either medial/lateral, or fore/aft issues derived from boot geometry, they are not also available for other uses.  To do so would countermand the Prime Directive.  If the distance from your clients’ heel to hip varies little from one turn to the next, despite your repeated suggestions to the contrary, look to the boot for answers.

This ‘Kinetic chain lockup’ is primarily related to ramp, with medial/lateral considerations as a secondary cause.

Steer and counter-steer.

The articulations of an unhindered ‘ankle’ joint are very similar in function to the steering axis on a bicycle or motorcycle.  Point the wheel to the right; create a lean to the left.  Point your toes to the right; create a turn to the left. (Important to note that this ‘pointing’ is not the result of leg rotation at the hip joint.)  Notice that if you evert your right foot, the corresponding inside edge of your right ski will engage with the snow…

Compromise the mobility of the ankle joint, and this option is ‘off the table’ so to speak.

Perhaps the most significant aspect of steer and counter-steer via ankle articulation is that the geometric relationship between the ski and the snow may be altered without involving the knee and associated muscles.  This preserves the possibility of free articulation of the leg as a means of controlling/utilizing the energy stored in the ski. (Hooke’s law, F=-KX)

Unfortunately, free articulation of the ankle joint is not all too common, as, one way or the other, many skiers find themselves at odds with their boot geometry.

And thus, mediocre becomes the new awesome, as skis change shape to make up the for the inabilities of the athlete to ‘move’.