Proprioception :
the sense of self-movement and body position.

Even with our eyes closed, we know where our limbs are situated, what load they are carrying, or what angles or joints are bent at.

This self-awareness is obviously extremely important in jiu-jitsu.

It is equally as important to constantly be aware of the opponent’s body, and as there are apparently no words for that yet, I hereby propose : Alioception.

Proprioception (n.)
1906, from proprioceptor, from Latin proprius “own” (see proper) + reception. Coined by English neurophysiologist C.S. Sherrington (1857-1952). Related: Proprioceptive; proprioceptor.
“the sense of self-movement and body position.”

Alioception (n.)
2020, from Latin alius “other” + reception. Coined by Jelaludo. Related: Alioceptive.
“The sense of another’s movements and body position upon touch.”

固有受容性感覚、自己受容性感覚、固有受容、自己受容

Proprioception :

固有感覚（proprioception）は、四肢の位置や動き、関節の曲り具合、筋肉の力の入れ具合などを感知するものです。筋・腱・関節など自分の身体内部の状態を知るための感覚なので、「自己受容感覚」とも訳されています。

Alioceptionは上記と同じですが、「相手の体の感覚」、相手の四肢の位置や動き、関節の曲り具合など。「外体感覚」？元々英語にまだ存在しない言葉の和訳が難しい！