|
6#
楼主 |
发表于 2014-3-8 19:22:16
|
只看该作者
本帖最后由 KuoiGuaBoarder 于 2014-3-9 19:36 编辑
EDGING
Edging and Direction Change
When there is a change of direction, edging is involved. Edging provides the grip that counters
the force of gravity and centrifugal force, keeping the skier turning. The degree of edging is
determined by how fast the skier is going when they turn, and whether they wish to de-
celerate, maintain speed or accelerate. Good edge control makes the ski grip but allows maximum
gliding for any given direction change.
Edging and Pressure Control
Turning on an edged ski or skis generates forces that give the skier a sensation of weight, or
pressure. When the skis are flattening (phase 1) they are releasing their grip and the load against
the snow diminishes. When the skis are turned across the line of travel (phase 2, 3) forces build
and the COM gets deflected. Edge angle increases and pressure builds. Bigger forces from higher
speeds and steeper terrain place greater loads on the skier which must be managed.
Inclination and angulation
Inclination refers to the line of lateral balance between the BOS and COM. This degree of lean is
what the skier must do to counteract the forces of the turn, and it changes within each turn in
response to speed, external forces and intended path of travel. Too much lean and the skier stands
on the inside ski or falls over, and not enough makes it impossible to maintain the arc of the turn.
Angulation is the bending of body segments as the skier inclines. Controlled by the use of ankles,
knees and hips, it keeps the skier in balance against the edges and lets the skier produce edge
angles that are greater than what can be achieved with inclination alone.
Turn Initiation – changing the line of inclination
While balanced on an arc, the COM is inclined to the inside of the BOS. To change direction, the
skier must change this line of inclination, putting the COM to the inside of the new arc. A wedge
or stem is a way of placing the BOS to the outside of the new turn, changing the line of
inclination to the new side.
In parallel skiing this “toppling” can be achieved by releasing pressure on the outside ski and/or
transferring it to the other ski. This effectively shifts the BOS from the downhill ski towards the
outside of the new arc, changing the line of inclination. A smooth release in phase 1 is also a way
of getting the COM to the inside of the new arc. Most edge changes involve combinations of
these elements, and can be passive or active, simultaneous (parallel) or sequential (wedge),
depending on the skills and desires of the skier.
Note: See Biomechanics and skiing: Stability, Direction,Impulse, Angular motion, Angular momentum, as well as Planes of balance: lateral.
|
|