本帖最后由 firehawk 于 2012-12-1 21:30 编辑
原作者：Paul Lorenz
日本室内讲座Japan Indoor Lecture “靠重力，而不是肌肉”Gravity, not muscles
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我一直都希望多了解日本的系统，特别是现在我在日本工作的这时候。我经常看见日本教练在山上讲授十分奇怪的，我从未见过的动作。这引起了我的兴趣，于是我决定要与日本队一同滑雪，并听听他们使用这些动作的缘由。
在进入雪地之前我参加了日本的室内讲座，这对理解他们的雪上展示很有帮助，因为他们在雪上的示范很短很清晰，但没有解释太多。 日本队教练以及一位被雇于帮助他们研发新技术的物理学教授一同给予了这场讲座。
演讲先是关于日本滑雪文化的一些有趣故事。在80年代晚期以及90年代初，日本的滑雪度假村发展飞速。在1993年时有过将近950个滑雪场以及1800万人的滑雪人口。滑雪迅速成为了日本的民族运动，并且吸引了包含老年人在内各年龄段人群的参与。
几年以后，滑雪的价格以及相关伤亡大大增加。导致滑雪运动在日本人中的受欢迎程度大打折扣。在2010年，开业的滑雪场锐减至350家，同时滑雪人口降至大约900万人。 这种情况使SAJ（日本滑雪协会）重新审视他们的滑雪技术，并开始研发一种更新颖更容易掌握的技术，使身体承受更少的压力，并减少受伤的风险。
他们开始寻找其他转弯的途径，主要着重于加大对重力的利用，而非肌肉力量。 物理教授展示了一系列他们研究这种所谓Hybrid Turn“混合转弯”技术时记录的实验录像。这些实验起始于区区一条坡道和一个小球。我们知道如果你让一个小球横于坡道滚动，随着其“惯性”运动减弱，重力的介入，球会被拉向坡底。于是小球会朝着坡底划出一道完美的弧线。
这个实验证明了任何滑雪转弯的前半段可以完全交给重力来执行。然后他们又想出了一种办法来结束当前的弯，并使滑雪者进入另一个方向的新弯。他们使用了许多不同的形状和物体来进行实验，直到他们受到“杯子”的启发。杯子的底部半径小于顶部，这意味着你把杯子放到坡上让它滚动，它会绕着弧线返回到“山上”。通过这个实验，日本人开始试图把自己的身体模仿成杯子的形态（内侧比外侧短）。他们将此称之为“双轴控制”，希望重力对人会产生与杯子相同的效果。
这么做可以完美的划出第一个弯，可是怎么把一连串的弯联系到一起呢？ 下面一系列的实验中，日本人把两个杯子沿着杯沿粘到一起，当杯子从坡上滚下时，重力会使小球滚入靠底端的杯子中，导致这个杯子不得不继续下降，随后两个杯子划出新的弧线。 然后不断重复这个过程，结果是两个杯子仅在重力作用下做到“回转”。
这个实验的奇妙之处在于：小球的位移路线与滑雪者向山下滑行时重心相对于雪板的位置是完全一致的。
如果一个滑雪者将外侧腿放松，并允许重力把他的重心往山下拉动（如同以上实验），重心会穿过雪板，将板底放平，从而开启新弯。日本人在这些试验中已经证明了这个过程是不需要肌肉力量参与的，同时不需要膝盖产生扭矩（进行扭转）。所以这种滑法更安全更轻松。
这种日本正在雪场上教授的新技术被称作“混合转弯”。日本人相信这种新技术会大大减少滑雪受伤的案例，并将被受伤案例“吓跑”的较老一代人吸引过来。他们向所有级别的滑雪者教授这个新技术，无论是什么地形或速度。 随后进入雪上讨论阶段。 我们非常幸运的可以同日本最著名的示范员、全日本比赛冠军井山敬介一同滑雪。在雪上示范时，因为英文能力有限，他们并没有做出太多动作解释。但是他们还是示范出了这种混合转弯，并试图从我们学习使用这种技术的情况来得到反馈。当时我们的Andrew Rae 十分欣喜，并向其他的国家的教练解释日本人想要表达的概念其实非常有意思。这个技术对许多国家的教练来说很难掌握，因为它并不包含直接的施压，外推，扭转之类他们以为会出现的动作。
我十分赞赏他们试图创建更新更好的技术，希望新技术可以增加雪场人数的理念。 这个技术对新手来说绝对是易于掌握的，因为是很多滑雪者最后自然而然产生的动作。但它尽管在实验中得到了验证，在真正实践过程中的效果却有所差异。我们经常会注意到井山敬介身体倒向了内侧板，而外板沿着原先的轨迹继续前进。这时他利用他的力量、平衡能力和滑雪技术修正了问题，而这些能力是大多新人所不具备的。我同样认为，这些技术在某些特定的雪况下会更合适，在澳大利亚的硬雪面上是否奏效有待商榷。
总而言之，这堂课很有意思，而且解答了许多我对之前看到的新鲜练习技巧所产生的疑惑。 [size=14.399999618530273px] ![]()
[size=14.399999618530273px]附原文：
Japan Indoor Lecture
Gravity, not muscles
by Paul Lorenz
I had always wanted to learn more about the Japanese system, particularly now that I am working in Japan. I have often seen Japanese instructors teaching very strange movements out on the hill, very different to anything I had ever seen before. I found this interesting and had therefore made up my mind that I wanted to ski with the Japanese team and listen to their justification of these movements.
I attended the Japanese indoor lecture before heading out on the snow. This proved to be very useful as the on snow portion of the presentation was short and demonstrative, without too much talk.
We were spoken to by the Japanese team coach and also by a physics professor who was employed to develop new ideas about ski technique. The lecture started with some interesting facts about the Japanese skiing culture. Towards the late 80’s and early 90’s there was a boom in the development of ski resorts within Japan. In 1993 there were approximately 950 ski areas with a skiing population of around 18 million. Skiing quickly became one of the Japanese national sports and attracted people of all ages including the older generations.
Over the years the price of skiing and the amount of ski related injuries increased substantially. This saw a decline in popularity among the Japanese people. In 2010 the number of ski areas in operation had dropped to around 350 with a skiing population of approximately 9 million.
This prompted the SAJ to have a look at their ski technique and develop new, more achievable technique that put less stress on the body and lowered the risk of injury.
They started to look at other ways of making a turn, mainly using gravity with less emphasis on muscular effort. The professor had videoed a series of experiments that they had performed to come up with their new ski technique known as the Hybrid Turn. These experiments started with just a ball and a slope. As we all know, if you roll a ball across a slope, as the inertia fades the gravity takes over and pulls the ball down. As this happens the ball makes a perfect arc towards the bottom of the slope.
This proves that the first half of any ski turn can occur with just the allowance of gravity to play its part. They then had to figure out a way to finish the turn so that it would end up going back across the slope in the other direction. They experimented with many different shapes and objects until they stumbled across the idea of the cup. A cup has a smaller radius at the base than it does at the brim. This means that when you roll a cup on its side down a slope it will follow an arc around the base of the cup until it turns back up the hill.
With this experiment the Japanese started to play around with shaping their body in a similar fashion to a cup (shorter on the inside and longer on the outside (they named this “dual axis control”) hoping that gravity would act in the same way as it does with the cup.
This was all well and good for 1 turn, but how would they link these turns together? The next series of experiments saw the Japanese taping 2 cups together by their brim with a solid ball inside. As the cups rolled across the slope, gravity would pull the ball down into the lower cup forcing it to drop and cause the cups to now arc around the new, lower cup. This would repeat itself all the way down the slope, seeing the 2 cups link turns with only the use of gravity.
What was very interesting about this experiment was the path that the ball took was identical to the path that a skiers’ centre of mass takes in relation to the skis, when skiing down the hill.
If a skier relaxes the outside leg and allows gravity to pull their centre of mass down the hill (as in the experiment), the COM passes over the skis which in turn flattens them, and the new turn will initiate. The Japanese had proved with these experiments that no muscular effort was needed, no torque or twist on the knees was needed and therefore this is a much more user friendly and injury free way of skiing.
This new technique is called the “hybrid turn” and is what is being taught on the Japanese ski fields at the moment. They believe this new technique will cut down on ski related injuries and attract the older generations that have been scared off skiing as a result of injuries. They are teaching this technique to all levels, at all performances on all terrain.
We then went out for the on snow clinic. We were lucky enough to ski with one of the most famous demonstrators and competition winners in all of Japan, Keisuke Iyama. During this on snow clinic they did not explain very much as their English was limited. They did however demonstrate the hybrid turn and attempt to give feedback on our performance of this technique. Andrew Rae alsochimed in now and then, explaining to other countries what they really meant which was quite entertaining. This technique was hard to grasp for a lot of countries as it does not involve any direct pressing, pushing or twisting that they all come to expect.
At the end of the day I admire the intent to create new and better technique and hope that this leads to the increase in the amount of skiers seen on the Japanese ski fields. This technique is definitely achievable for beginners as this is what most new skiers end up doing naturally. While it seems very interesting and justified through these experiments, when put into practice proves to be a little different. We often observed Keisuke falling to the inside with his outside ski splaying off on its own course. This was handled with his strength, balance and understanding of skiing but may not be handled by the average beginner. I also think that this technique can be more suited to certain snow conditions. It is debatable if this would be successful on the icy snow fields of Australia.
All in all it was a fun session and answered a lot of the questions I had about the funky Japanese exercises I had seen being used.
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发表于 2012-12-13 17:10:14
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