一ヶ条（三）支點滑動
｜ Ikkajo 3: Fulcrum Sliding

支點滑動在大東流的技術中隨處可見，以下主要用一亇条做為解釋。

一般認知: 一亇条或其他類似技術中，取方用手控制住受方的肘跟手腕時，以取方手肘為支點且前臂為力臂，意圖推動受方的上半身，如果手肘支點為固定，前臂的力臂距離較短，要推動受方上身重量，要輸出的力量若只是槓桿力學是難以達成。再者，不論是要推動對方向上或往下，取方若僅以手肘做為支點，透過前臂的伸展外推跟收回執行樞轉，受方因為容易感知到取方手肘(支點)存在，取方前臂與受方的連結反而成為受方抵抗的力矩，藉由頂回取方手肘(也就是，受方將取方手肘作為支撐點)，樞轉的手肘點在此時是取方支點也是受方支撐點，因而僵持。

在不考慮變招的研究之下 (當然在實際應用時應該變招，在練習中一遇到抵抗就變招，等於逃避技術失敗的事實)，透過對大東流一亇条的框架研究，我們認為一亇条可能包括支點滑移的技術，意思是，在上述前提中，取方手肘也作為受方支點，但如果我們將支點拿掉呢？也就是本來受方透過取方手肘作為抵抗的支撐點，若此時支點產生無法預期的移動，受方將會難以抵抗。

此處有個最大困難點：如果支點移動被受方認知到，受方將會放棄將取方手肘作為支撐點，而把重心回歸自身，所以取方單純將手肘支點移動的效果是不夠的。

我們觀察到，例如以抱腰擒抱來說，取方如果用腰部為支點往下，受方其實反過來使用取方的腰作為抵抗的支撐點。但如果取方以捨身擒抱的方式（一樣擒抱腰但取方目標是連同受方一起往下倒，不論取方最後是否實際捨身倒下），受方體感上很難找到抵抗的支撐點，因為本來可以抵抗的支撐點墜落，使得受方突然失去重心，這個現象暫時命名為「支點滑動」，之所以為滑動是因為單純的移動支點會讓受方改變對支點的依靠，但如果是如同踩到積水磁磚一般的瞬間滑動行為，會讓受方跟著支點一起移動。我們也發現在一亇条的執行過程中，不論是往上跟往下的崩，帶有支點滑動的技術會讓一亇条產生本質上的改變而讓輸出變得極小。

ulcrum Sliding in Daito-ryu Techniques

Fulcrum sliding can be seen everywhere in Daito-ryu techniques. Below, ikkajo is mainly used as an explanation.

General understanding:

In ikkajo or other similar techniques, when the tori uses their hands to control uke’s elbow and wrist, the tori’s elbow is treated as the pivot, with the forearm acting as the lever, intending to drive uke’s upper body. If the elbow pivot is fixed, the lever length of the forearm is relatively short, making it difficult to move the weight of uke’s upper body by leverage alone. Furthermore, whether tori intends to move uke upward or downward, if the elbow is used solely as the pivot, with the forearm extending outward or retracting as the lever, uke can easily sense the presence of tori’s elbow (the pivot). In this case, the forearm connection between tori and uke actually becomes a torque point of resistance. By bracing against tori’s elbow (in other words, uke treats tori’s elbow as a support point), the pivoting elbow point becomes both tori’s pivot and uke’s support, resulting in stalemate.

If we study the framework of ikkajo without considering alternative variations (of course, in practical use one should switch techniques; in practice, encountering resistance and then changing technique is essentially avoiding the fact that the original attempt failed), we conclude that ikkajo inherently includes a method of fulcrum sliding. That is, under the above conditions, although tori’s elbow also serves as uke’s support, what if the pivot is removed? In other words, uke resists by treating tori’s elbow as a support point, but if the pivot suddenly shifts in an unexpected way, uke will find it difficult to continue resisting.

Here lies the greatest difficulty: if uke perceives the pivot’s movement, uke will abandon treating tori’s elbow as a support point and instead return their center of gravity to themselves. Therefore, simply moving the elbow pivot with the shoulder or hips is insufficient.

We observe, for example, in a waist-clinch hold: if tori drives downward using the hips as a pivot, uke can actually reverse this, using tori’s hips as the support point for resistance. But if tori instead applies a sacrifice clinch—still holding the waist, but aiming to bring uke down together with them (regardless of whether tori actually falls down in the end)—uke, in terms of body sensation, finds it very difficult to identify a support point for resistance. This is because the very support point they could have relied upon collapses, suddenly causing uke to lose balance.

This phenomenon is temporarily termed “fulcrum sliding.” The word “sliding” is used because a simple movement of the pivot causes uke to shift reliance, but a sliding action—like the instant slipping one feels when stepping on a wet tile—makes uke’s body move together with the pivot.

We also observe that in the execution of ikkajo, whether in the upward or downward collapse phases, techniques that incorporate fulcrum sliding fundamentally alter ikkajo, making the required output force extremely small.