VONN VS. FENNINGER


Camera angles and the sometimes less than sharp picture quality of  World Cup race coverage can make it difficult to critically analyze ski technique. It doesn’t help that cameras often switch views or gate flags obscure racers just as an important event is occuring. But there were three sections of the January 19, 2015 Cortina d’Ampezzo Super G, won by American, Lindsey Vonn by a convincing 0.85 second margin over second place Austrian, Anna Fenninger, that clearly demonstrated Vonn’s superior technique.

The video clip below compares Vonn to Fenninger in two sequences with a third sequence of Vonn.

 

In the first sequence, Vonn is ahead of Fenninger by 0.4 seconds as she passes the gate (Vonn –  estimated at 33.8 seconds vs Fenninger – estimated at 34.2 seconds). The most important Event of an effective ski technique is Event 7 (whole leg top down internal rotation). This requires inside ball of the foot to outside heel boot shell force-coupling while maintaining force over the inside edge of the outside ski with the load W on the head of the first metatarsal. The position of a racer at Event 3 (ski flat) and in especially whether Event 4 (load transfer induced pronation) occurs, provides a good indication of what the racer is able to do in the subsequent turn phase. Depending on the alignment of the load W and the resultant force R emanating from COM in relation to the inside edge of the new outside ski, the ski/foot/leg will either rotate into the turn or out of the turn. The sketch below shows the two possible options for the ski lever – DOT 10: SKI LEVERS – https://skimoves.me/2014/11/19/dot-10-ski-levers/

The vertical grey box represents a lift height from the base of the ski to the plane of the boot board of approximately 90 mm in relation to a 65 mm ski width underfoot. The graphics represent a frontal view of the ski/equipment system with approximately  3 degrees of edge angle into a right hand turn as represented in the first video sequence of Vonn and Fenninger.

Ski Lever OptionsClick on the image to enlarge it

If the load W is on the inside turn aspect of the inside edge as shown in the left hand graphic above, a platform of contiguous ground reaction force exists on which to support the racer and engage the external forces to drive the ski into the turn. If the load W is on the outside turn aspect of the inside edge as shown in the right hand graphic, the edge will not grip and the ski will tend to slip away from the turn as the forces acting on the ski build.

The racer has two options with which to resist the loss of edge grip of the outside ski, 1) use what is incorrectly referred to as knee angulation (adduction of the hip in combination with some internal rotation of the whole leg) or, 2) move to the inside ski and increase the inclination into the turn. Neither option is as effective as a platform under the outside ski where the load W is acting on the inside turn aspect of the inside edge. Without a contiguous source of ground reaction force with which to apply force to the ski and generate postural responses to perturbations in GRF, superior strength and conditioning are irrelevant. Precisely carved ski turns are replaced by a series of linked recoveries. Survival instincts and acrobatics, not skill and superior technique, prevail.

In the first sequence, as Vonn comes around the gate, she rotates her outside leg and ski across her trajectory, loads and locks the inside edge and  neatly cuts off the turn. That her outside ski does not appear to oscillate in the high load phase of the turn suggests that she has successfully executed Events 4 through 7. As Fenninger comes around the same gate, she appears to be carving a clean turn on her outside ski. But this is an illusion. If you watch carefully, you will see that she appears to have much more weight on her inside ski than Vonn. Fenniger appears to be using her outside ski to steady her position on her inside ski.

The next sequence is even more telling. The fluidity with which Vonn moves from one turn to the next attests to the continuity of the coordinated lower limb muscle activity across the bridge of her pelvis. This is also evident in the last sequence of Vonn. By comparison, Fenninger makes a move from the old turn to the new turn that is both awkward and disruptive of the processes of balance as it pertains to neural flow. The hallmark of the world’s best skiers has always been that they maintain and control pressure on the outside ski from the start of a turn to the finish. – DOT 13: INNATE FLOW BALANCE –https://skimoves.me/2014/12/04/dot-13-innate-flow-balance/‎

The question is whether the move to the inside ski is a part of a deliberate technique or a reflex action arising from a loss of edge grip on the outside ski. Since others appear to be using a similar move it seems to have become an established technique as evidenced by Germany’s Felix Neureuther in the short clip below from the recent men’s slalom in Wengen. The tight timing of slalom is one thing. Super-G is another whole matter.

 

In my mind the issue is not who the best ski racer is but rather whether all racers are realizing their full human performance potential, especially as it pertains to the physiological processes that defend against injury. If racer A is at 95% of their maximum potential and racer B is at 80%,  is the best athlete winning? I don’t think so. In formula one racing, the combination of the best driver and the best race car consistently win. In ski racing it should also be the combination of the best racer and the best equipment tuned to the racer, that consistently wins. I have not seen evidence that this model is part of the current paradigm. The question is why not?