“Yet a further problem relates to the efficient transfer of torque from the lower leg and foot to the footwear. When the leg is rotated inwardly relative to the foot by muscular effort, a torsional load is applied to the foot. Present footwear does not adequately provide support or surfaces on and against which the wearer can transfer biomechanically generated forces such as torque to the footwear. Alternatively, the footwear presents sources of resistance which interfere with the movements necessary to initiate such transfer. It is desirable to provide for appropriate movement and such sources of resistance in order to increase the efficiency of this torque transfer and, in so doing, enhance the turning response of the ski.

“The most important source of rotational power with which to apply torque to the footwear is the adductor/rotator muscle groups of the hip joint. In order to optimally link this capability to the footwear, there must be a mechanically stable and competent connection originating at the plantar processes of the foot and extending to the hip joint. Further, the balanced position of the skier’s centre of mass, relative to the ski edge, must be maintained during the application of both turning and edging forces applied to the ski. Monopedal function accommodates both these processes.” – MacPhail, US Patent No 525,265, 350 November 30, 1993 in reference to conventional ski boots and ski technique

COMMENT: The application of torque to the outside ski of a turn resulting from balancing on the outside leg (monopedal stance) and applying rotational force to the leg from the pelvis engages and loads the shovel of the ski while enabling edge hold at angles of the base with the snow in excess of 45 degrees.

As more racers like Federica Brignone adopt a technique based on the application of torque to the outside ski, they will suddenly begin to appear on the podium.

Here is a clip of Brignone in very slow frame-by-frame. Watch carefully as she Rolls Over and applies rotation to her outside ski as evidenced by movement of her knee into the new turn. As she crosses the fall line, her outside ski will be seen to converge at the shovel with her inside ski then lock up with the snow, closing the kinetic chain and translating rotation of her leg into rotation of her ski about its length into the the turn. Brignone is using the powerful rotators in her pelvis to wind her outside ski into the turn like a corkscrew against external torque that is unwind her outside ski out of the turn resulting in a loss of edge grip.

Molto Bene Federica!