#21 回覆: cross-under 應該是在做 down-unweighting
發表於 : 週二 3月 24, 2015 4:14 pm
光速。norman 寫:請問,這意思是什麼?![]()
光速。norman 寫:請問,這意思是什麼?![]()
如果是LELO所說的「光速」。B2L2 寫:Next question, how fast could Norman pull up his legs?


我指的「死胡同」沒有任何不好的意思,僅指我們的討論方向及思考方向。B2L2 寫:First, don't assume other are in 想入死胡同了. It could be equally possible that you are in 死胡同. Keep in open mind for discussion. :)
I don't see my question being strange. We are discussing method to keep COM stable (related to the ground, I assume), right?
First, if there is no support under your COM, COM will free fall and be accelerating towards the group in 9.80665 m/s^2 (pulling by Early garvity). So in order to "lift" the feet off the group, how fast you need to pull your legs?
這次可能有稍看懂了一些,我重覆一下你的問題。B2L2 寫:Nope, you got it wrong. And actually, the question isn't to you alone. It's a discussion. I am not here to point out you have something wrong. Don't misunderstand.
Okay, let's try again. If you are standing on the ground stationary (no motion). How fast you have to "pull" your left in order to left your feet off the ground without changing the COM location?
I know the moment your feet left the ground, you body will be free falling towards the ground. Could you actually pull your legs faster then gravity pull you down?
這段是最後一次拍的,可以注意看慢動作肩膀的位置,完全沒有上移。B2L2 寫:You still have the video that shows you practicing up-weight at home, Norman? Could you post that again?

norman 寫:這段是最後一次拍的,可以注意看慢動作肩膀的位置,完全沒有上移。
只是那時曾有雪友說我用墊腳尖跳的,不然就是說蹲夠快也是可以,我實在很無言。
我只能說信就信,不信依然不信吧?
https://youtu.be/cbTs4U5UM3U

你大便時的姿勢怎麽那麽臭norman 寫:這段是最後一次拍的,可以注意看慢動作肩膀的位置,完全沒有上移。
只是那時曾有雪友說我用墊腳尖跳的,不然就是說蹲夠快也是可以,我實在很無言。
我只能說信就信,不信依然不信吧?
https://youtu.be/cbTs4U5UM3U

我也這麼覺得,肉吃太多了,最近真的天天在吃「六味地黃丸」。skier888 寫:你大便時的姿勢怎麽那麽臭![]()
Good demo there, Norman. Is this the basic form of your 「拉提收縮」 then?norman 寫:這段是最後一次拍的,可以注意看慢動作肩膀的位置,完全沒有上移。
只是那時曾有雪友說我用墊腳尖跳的,不然就是說蹲夠快也是可以,我實在很無言。
我只能說信就信,不信依然不信吧?
https://youtu.be/cbTs4U5UM3U
是的,這只是入門而已,只是讓學會的人體會什麼叫做「自主收縮雙腳」,後面要做的其他動作練習需要靠這個收縮動作,來確保自己是用「收縮」的動作,而不是「蹲下」的動作,兩者使用的肌肉方式不一樣。B2L2 寫:Good demo there, Norman. Is this the basic form of your 「拉提收縮」 then?
其實我一直在想,不知哪天才會有人問我這些問題呢?難得。B2L2 寫:You said "靠腹肌收縮的爆發力去拉雙腳,收腳的速度要比由靜止開始自由落體的速度快。改變方向則要靠髖骨的轉動。"
If a skier needs to 爆 in every turn, is that very tiring? And even 爆, you could only pull up like 1 feet off the ground and only last like half a second. This is very hard to control.
So could I ask what other force involves during skiing that make it less tiring?

Even you said it, nobody could find the difference. Let said it is just internal movement then. I could understand the difference between the two.norman 寫:是的,這只是入門而已,只是讓學會的人體會什麼叫做「自主收縮雙腳」,後面要做的其他動作練習需要靠這個收縮動作,來確保自己是用「收縮」的動作,而不是「蹲下」的動作,兩者使用的肌肉方式不一樣。
我去從以前的影片截出來重新傳上來給你們看一下,如果我不說,你們分得出兩者動作的差別嗎?
You know what we are thinking? The reason you can't correct us is because of what? Again to hard to explain?norman 寫:其實我一直在想,不知哪天才會有人問我這些問題呢?難得。
事實上「拉提收縮」的最終動作不是你們想的這樣子,就算你拿它來做「豚跳」,也是無法直接拉起雙腳的。
How possible to use other muscles to help this? That I cannot agree. If you hold your arm muscle too tight, you lost your flexibility. Why don't make use of those muscles to do other work (like maintain balance is a major task).norman 寫:而在實際滑雪時,在一般中級轉彎以下,不需要這麼用力來拉雙腳的,用到的力量是非常小的,腿先酸,腹部都還不一定感覺到累呢,何況我說過,是用全身的力量去做,把力量分散到全身的力量,這腹肌所需要的力量還會更低,但不可否認,在家裏練習時,腹肌是痛苦的,後面的練習足足讓我的腹肌痛一個月,然後就不痛了。
Your skiing being showed was pretty slow, and so as all the force involved in your skiing was pretty low. I doubt what you had experienced (or understood) covered everything. It could be possible that you're practicing something without a complete picture.norman 寫:想想看,滑道是有斜度的,當我們在滑行時,有速度時,重心質量是不可能跟雪面產生垂直90度掉下去的,所以如果雙腳雪板都不碰雪面時,在有速度下一定是拋物線掉下來的。所以用到腹肌「爆發力」的時間其實只需要很短的時間,就是只有在滑高級轉彎動作時,鋼邊換鋼邊時才需要而已,但也沒想像中需要那麼用力,因為還有速度及離心力跟反作用力幫忙。
I had too little understanding on your 正確傾. Maybe you should start another topic for that.norman 寫:沒練習當然難控制囉,如下這段家裏第二階練習的影片,正確傾還要靠這個練習幫點小忙呢:
https://youtu.be/vJCTNCx_uEE
所以勞不勞累,我覺得練習時比較累,因為不熟,肌肉難免會多用點力,為了達到目標動作也會比較僵硬一點,動作熟練不需要練習又不怕陡度跟速度,還可以更輕鬆一點,取決於對動力運用的深淺,淺就雙腿容易耗力一點,深就比較省力一些,另一個方式就是平常多運動點,不要像我一樣,最近才試練習做淺蹲不到二十下就快不行了,雙腿實在是有夠沒力了,這樣的腿力我只能保證二百~四百公尺不休息,綠彎不用休息,紅線大概一公里左右,彎越小就越短。因為想要腹部先沒力會酸,那是不可能的,一定是雙腿先沒力。
This video is useless for us, showed so many things without explanation.norman 寫:剛才看到這段影片,我上面幾乎沒有說明,我記得我好像有貼出來過,現在在放出來看看,上面都是我在2014年去野澤之前的心得,雖然有些小部份要修改一下,但大體是不變的。
再拿出來讓大家看看一下也不錯。
https://youtu.be/e6iVWt_ec5U
我的意思只是說從外觀看兩者的動作是沒差別的,不說明的話,可能連我也看不出來。B2L2 寫:Even you said it, nobody could find the difference. Let said it is just internal movement then. I could understand the difference between the two.
沒提問,沒法修正或是討論,畢竟我也不可能知道大家在想什麼,也許我們想的是同一個詞,同一個意思,但對問題的觀點及理解不同時,就沒那麼容易了。B2L2 寫:You know what we are thinking? The reason you can't correct us is because of what? Again to hard to explain?
可能不是你想的這樣子,一塊肌肉是立體的,可以有很多種方向的變化,使用到這塊肌肉不代表你有使用到這塊肌內的每一個部份角落,只是可能我們平常使用這塊肌肉的A部份右方向,而沒使用到的B部份上方向,那我們就會不知道如何去使用那部份肌肉,所以這時要靠意識力及正確的動作去練習,越練習使用的會越完整。B2L2 寫:How possible to use other muscles to help this? That I cannot agree. If you hold your arm muscle too tight, you lost your flexibility. Why don't make use of those muscles to do other work (like maintain balance is a major task).
這是中級轉彎,不是嗎?中級轉彎的速度不就差不多都是這個樣子?只是中級轉彎還是有分正確跟不正確的,內含技術量的多寡,取決會不會看而已。B2L2 寫:Your skiing being showed was pretty slow, and so as all the force involved in your skiing was pretty low. I doubt what you had experienced (or understood) covered everything. It could be possible that you're practicing something without a complete picture.
是指下面這個嗎?我該講的都差不多都講了吧?B2L2 寫:I had too little understanding on your 正確傾. Maybe you should start another topic for that.
確實是,這可以看成只是我個人的心得,畢竟我在上面幾乎沒有任何解釋,看得懂就看得懂了,看不懂還是看不懂的。B2L2 寫:This video is useless for us, showed so many things without explanation.
你說的是這個嗎?snowrider 寫:弱慢兄 怎麼這看了好像你在練什麼嚇人的神功
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