動量與合氣：為什麼對手會失去平衡
｜ Momentum and Aiki

練習模式通常有幾種：對方先攻、我方先攻、以及作招時遇到抵抗的變招

如同多數合氣體系武術，對方(aka Uke 受け)先攻的練習佔多數，不過練習時，Sensei永遠告誡心態必須是攻擊而不是防禦，所以不管對方先攻或我方先攻，只是時機上的不同，永遠都是攻擊技。

雖然練習模式是不配合不抵抗，但所謂不抵抗並非任人宰割(任人宰割不就等於配合了嗎？)，如果練習者(aka Tori 取り)沒能處理好技術，或是某些招式過程中很容易產生不必要的施力讓受方(Uke)身體產生抗力，因此第三種練習模式就是要能從A招遇到狀況馬上轉換成B招。

回到主題，上面三種練習模式，基本都要阻斷對手，也就是說，類似劍術受流(Ukenagashi，將對手的攻擊引導吸收後再反擊)的技術有但不多，理由可能是，在對手的動量(質量X速度)之下，時間短，不可控因素太多難以做到引導反擊，更何況難以預測對方打擊組合的下一步。個人猜想，所有的打擊系武術都要阻斷對手攻擊，因為不阻斷光靠受流，下場可能是在受流過程中對方就用上整套組合技了。

在我們的練習中，不論哪種練習模式，都要將對方阻斷後，這時我們稱為零點（從零開始做招式），練習者要面對的課題就是如何從零開始處理技術，過程就是前文提過的崩作掛程序。有些狀況是，阻斷對手時，對手的動量仍在往前，此時提供崩(破勢)的時機，但時機稍縱即逝，如果沒能掌握時間差(對手動量煞停後恢復重心)，也是要從零點開始做起。

至於如何從零點開始破勢，這就回到合氣假說的理論，合氣是在對手無法感知下破壞重心的技術，變動支點可能是方式之一，這也是為何合氣練習會如此重要，所有技術都會用到合氣的部分或全部。

Our Daito-ryu practice typically involves three modes: the opponent attacks first, we attack first, and adapting techniques when encountering resistance. 

Like most Aiki-related martial arts, the majority of practice focuses on the opponent (Uke) attacking first. However, Sensei always emphasizes that the mindset must be offensive, not defensive. Whether the opponent attacks first or we do, it’s merely a matter of timing—every technique is an attacking technique.

Although our practice avoids resistance or compliance, “non-resistance” doesn’t mean passivity. If the practitioner (Tori) fails to execute a technique properly or encounters resistance during certain moves, the third mode comes into play: seamlessly switching from technique A to technique B when faced with an issue.

On the main topic, all three practice modes fundamentally involve interrupting the opponent. Techniques similar to swordsmanship’s Ukenagashi (redirecting and absorbing the opponent’s attack before countering) exist but are rare. This may be because, under the opponent’s momentum (mass × speed), time is short, and uncontrollable variables make redirecting and countering difficult. Moreover, predicting the next move in an opponent’s combination of strikes is challenging. (I speculate that all striking-based martial arts prioritize interrupting the opponent’s attack, as relying solely on Ukenagashi could allow the opponent to unleash a full combination during the redirection process.)

In our practice, regardless of the mode, we interrupt the opponent, reaching what we call the “zero point,” where techniques begin anew. The practitioner’s challenge is to handle techniques from this zero point, following the process of “collapse, create, and connect” outlined in other articles.

In some cases, when interrupting the opponent, their momentum continues forward, creating a fleeting opportunity for “collapse” (breaking their posture). If the practitioner misses this timing—before the opponent regains balance—they must start again from the zero point. How to break the opponent’s posture from this point ties back to the Aiki hypothesis: Aiki is the art of disrupting an opponent’s balance imperceptibly. Shifting the pivot point is one method, which is why Aiki training is so critical—every technique involves some or all elements of Aiki.